Rollback to v2.0.0beta3 - reverting changes from v2.0.0

Reviewed-on: #28

analog_input.h

@@ -1,88 +0,0 @@
-/**
- * @file analog_input.h
- * @author Adam Wonak (https://github.com/awonak)
- * @brief Class for interacting with analog inputs.
- * @version 0.1
- * @date 2025-05-23
- *
- * @copyright MIT - (c) 2025 - Adam Wonak - adam.wonak@gmail.com
- *
- */
-#ifndef ANALOG_INPUT_H
-#define ANALOG_INPUT_H
-
-const int MAX_INPUT = (1 << 10) - 1;  // Max 10 bit analog read resolution.
-
-// estimated default calibration value
-const int CALIBRATED_LOW = -566;
-const int CALIBRATED_HIGH = 512;
-
-class AnalogInput {
-   public:
-    AnalogInput() {}
-    ~AnalogInput() {}
-
-    /**
-     * Initializes a analog input object.
-     *
-     * @param pin gpio pin for the analog input.
-     */
-    void Init(uint8_t pin) {
-        pinMode(pin, INPUT);
-        pin_ = pin;
-    }
-
-    /**
-     * Read the value of the analog input and set instance state.
-     *
-     */
-    void Process() {
-        old_read_ = read_;
-        int raw = analogRead(pin_);
-        read_ = map(raw, 0, MAX_INPUT, low_, high_);
-        read_ = constrain(read_ - offset_, -512, 512);
-        if (inverted_) read_ = -read_;
-    }
-
-    // Set calibration values.
-
-    void AdjustCalibrationLow(int amount) { low_ += amount; }
-
-    void AdjustCalibrationHigh(int amount) { high_ += amount; }
-
-    void SetOffset(float percent) { offset_ = -(percent)*512; }
-
-    void SetAttenuation(float percent) {
-        low_ = abs(percent) * CALIBRATED_LOW;
-        high_ = abs(percent) * CALIBRATED_HIGH;
-        inverted_ = percent < 0;
-    }
-
-    /**
-     * Get the current value of the analog input within a range of +/-512.
-     *
-     * @return read value within a range of +/-512.
-     *
-     */
-    inline int16_t Read() { return read_; }
-
-    /**
-     * Return the analog read value as voltage.
-     *
-     * @return A float representing the voltage (-5.0 to +5.0).
-     *
-     */
-    inline float Voltage() { return ((read_ / 512.0) * 5.0); }
-
-   private:
-    uint8_t pin_;
-    int16_t read_;
-    uint16_t old_read_;
-    // calibration values.
-    int offset_ = 0;
-    int low_ = CALIBRATED_LOW;
-    int high_ = CALIBRATED_HIGH;
-    bool inverted_ = false;
-};
-
-#endif

clock.h

@@ -1,194 +0,0 @@
-/**
- * @file clock.h
- * @author Adam Wonak (https://github.com/awonak)
- * @brief Wrapper Class for clock timing functions.
- * @version 0.1
- * @date 2025-05-04
- * 
- * @copyright MIT - (c) 2025 - Adam Wonak - adam.wonak@gmail.com
- *
- */
-
-#ifndef CLOCK_H
-#define CLOCK_H
-
-#include <NeoHWSerial.h>
-
-#include "peripherials.h"
-#include "uClock.h"
-
-// MIDI clock, start, stop, and continue byte definitions - based on MIDI 1.0 Standards.
-#define MIDI_CLOCK 0xF8
-#define MIDI_START 0xFA
-#define MIDI_STOP 0xFC
-#define MIDI_CONTINUE 0xFB
-
-typedef void (*ExtCallback)(void);
-static ExtCallback extUserCallback = nullptr;
-static void serialEventNoop(uint8_t msg, uint8_t status) {}
-
-class Clock {
-   public:
-    static constexpr int DEFAULT_TEMPO = 120;
-
-    enum Source {
-        SOURCE_INTERNAL,
-        SOURCE_EXTERNAL_PPQN_24,
-        SOURCE_EXTERNAL_PPQN_4,
-        SOURCE_EXTERNAL_MIDI,
-        SOURCE_LAST,
-    };
-
-    enum Pulse {
-        PULSE_NONE,
-        PULSE_PPQN_1,
-        PULSE_PPQN_4,
-        PULSE_PPQN_24,
-        PULSE_LAST,
-    };
-
-    void Init() {
-        NeoSerial.begin(31250);
-
-        // Static pin definition for pulse out.
-        pinMode(PULSE_OUT_PIN, OUTPUT);
-
-        // Initialize the clock library
-        uClock.init();
-        uClock.setClockMode(uClock.INTERNAL_CLOCK);
-        uClock.setOutputPPQN(uClock.PPQN_96);
-        uClock.setTempo(DEFAULT_TEMPO);
-
-        // MIDI events.
-        uClock.setOnClockStart(sendMIDIStart);
-        uClock.setOnClockStop(sendMIDIStop);
-        uClock.setOnSync24(sendMIDIClock);
-
-        uClock.start();
-    }
-
-    // Handle external clock tick and call user callback when receiving clock trigger (PPQN_4, PPQN_24, or MIDI).
-    void AttachExtHandler(void (*callback)()) {
-        extUserCallback = callback;
-        attachInterrupt(digitalPinToInterrupt(EXT_PIN), callback, RISING);
-    }
-
-    // Internal PPQN96 callback for all clock timer operations.
-    void AttachIntHandler(void (*callback)(uint32_t)) {
-        uClock.setOnOutputPPQN(callback);
-    }
-
-    // Set the source of the clock mode.
-    void SetSource(Source source) {
-        bool was_playing = !IsPaused();
-        uClock.stop();
-        // If we are changing the source from MIDI, disable the serial interrupt handler.
-        if (source_ == SOURCE_EXTERNAL_MIDI) {
-            NeoSerial.attachInterrupt(serialEventNoop);
-        }
-        source_ = source;
-        switch (source) {
-            case SOURCE_INTERNAL:
-                uClock.setClockMode(uClock.INTERNAL_CLOCK);
-                break;
-            case SOURCE_EXTERNAL_PPQN_24:
-                uClock.setClockMode(uClock.EXTERNAL_CLOCK);
-                uClock.setInputPPQN(uClock.PPQN_24);
-                break;
-            case SOURCE_EXTERNAL_PPQN_4:
-                uClock.setClockMode(uClock.EXTERNAL_CLOCK);
-                uClock.setInputPPQN(uClock.PPQN_4);
-                break;
-            case SOURCE_EXTERNAL_MIDI:
-                uClock.setClockMode(uClock.EXTERNAL_CLOCK);
-                uClock.setInputPPQN(uClock.PPQN_24);
-                NeoSerial.attachInterrupt(onSerialEvent);
-                break;
-        }
-        if (was_playing) {
-            uClock.start();
-        }
-    }
-
-    // Return true if the current selected source is externl (PPQN_4, PPQN_24, or MIDI).
-    bool ExternalSource() {
-        return uClock.getClockMode() == uClock.EXTERNAL_CLOCK;
-    }
-
-    // Return true if the current selected source is the internal master clock.
-    bool InternalSource() {
-        return uClock.getClockMode() == uClock.INTERNAL_CLOCK;
-    }
-
-    // Returns the current BPM tempo.
-    int Tempo() {
-        return uClock.getTempo();
-    }
-
-    // Set the clock tempo to a int between 1 and 400.
-    void SetTempo(int tempo) {
-        return uClock.setTempo(tempo);
-    }
-
-    // Record an external clock tick received to process external/internal syncronization.
-    void Tick() {
-        uClock.clockMe();
-    }
-
-    // Start the internal clock.
-    void Start() {
-        uClock.start();
-    }
-
-    // Stop internal clock clock.
-    void Stop() {
-        uClock.stop();
-    }
-
-    // Reset all clock counters to 0.
-    void Reset() {
-        uClock.resetCounters();
-    }
-
-    // Returns true if the clock is not running.
-    bool IsPaused() {
-        return uClock.clock_state == uClock.PAUSED;
-    }
-
-   private:
-    Source source_ = SOURCE_INTERNAL;
-
-    static void onSerialEvent(uint8_t msg, uint8_t status) {
-        // Note: uClock start and stop will echo to MIDI.
-        switch (msg) {
-            case MIDI_CLOCK:
-                if (extUserCallback) {
-                    extUserCallback();
-                }
-                break;
-            case MIDI_STOP:
-                uClock.stop();
-                sendMIDIStop();
-                break;
-            case MIDI_START:
-            case MIDI_CONTINUE:
-                uClock.start();
-                sendMIDIStart();
-                break;
-        }
-    }
-
-    static void sendMIDIStart() {
-        NeoSerial.write(MIDI_START);
-    }
-
-    static void sendMIDIStop() {
-        NeoSerial.write(MIDI_STOP);
-    }
-
-    static void sendMIDIClock(uint32_t tick) {
-        NeoSerial.write(MIDI_CLOCK);
-    }
-};
-
-#endif

digital_output.h

@@ -1,94 +0,0 @@
-/**
- * @file digital_output.h
- * @author Adam Wonak (https://github.com/awonak)
- * @brief Class for interacting with trigger / gate outputs.
- * @version 0.1
- * @date 2025-04-17
- * 
- * @copyright MIT - (c) 2025 - Adam Wonak - adam.wonak@gmail.com
- *
- */
-#ifndef DIGITAL_OUTPUT_H
-#define DIGITAL_OUTPUT_H
-
-#include <Arduino.h>
-
-const byte DEFAULT_TRIGGER_DURATION_MS = 5;
-
-class DigitalOutput {
-   public:
-    /**
-     * Initializes an CV Output paired object.
-     *
-     * @param cv_pin gpio pin for the cv output
-     */
-    void Init(uint8_t cv_pin) {
-        pinMode(cv_pin, OUTPUT);  // Gate/Trigger Output
-        cv_pin_ = cv_pin;
-        trigger_duration_ = DEFAULT_TRIGGER_DURATION_MS;
-    }
-
-    /**
-     * Set the trigger duration in miliseconds.
-     *
-     * @param duration_ms trigger duration in miliseconds
-     */
-    void SetTriggerDuration(uint8_t duration_ms) {
-        trigger_duration_ = duration_ms;
-    }
-
-    /**
-     * Turn the CV and LED on or off according to the input state.
-     *
-     * @param state Arduino digital HIGH or LOW values.
-     */
-    inline void Update(uint8_t state) {
-        if (state == HIGH) High();  // Rising
-        if (state == LOW) Low();    // Falling
-    }
-
-    // Sets the cv output HIGH to about 5v.
-    inline void High() { update(HIGH); }
-
-    // Sets the cv output LOW to 0v.
-    inline void Low() { update(LOW); }
-
-    /**
-     * Begin a Trigger period for this output.
-     */
-    inline void Trigger() {
-        update(HIGH);
-        last_triggered_ = millis();
-    }
-
-    /**
-     * Return a bool representing the on/off state of the output.
-     */
-    inline void Process() {
-        // If trigger is HIGH and the trigger duration time has elapsed, set the output low.
-        if (on_ && (millis() - last_triggered_) >= trigger_duration_) {
-            update(LOW);
-        }
-    }
-
-    /**
-     * Return a bool representing the on/off state of the output.
-     *
-     * @return true if current cv state is high, false if current cv state is low
-     */
-    inline bool On() { return on_; }
-
-   private:
-    unsigned long last_triggered_;
-    uint8_t trigger_duration_;
-    uint8_t cv_pin_;
-    uint8_t led_pin_;
-    bool on_;
-
-    void update(uint8_t state) {
-        digitalWrite(cv_pin_, state);
-        on_ = state == HIGH;
-    }
-};
-
-#endif

examples/clock_mod/clock_mod.ino

@@ -17,7 +17,7 @@
  *
  */
 
-#include "gravity.h"
+#include <libGravity.h>
 
 // Firmware state variables.
 struct Channel {

firmware/Euclidean/Euclidean.ino

@@ -0,0 +1,417 @@
+/**
+ * @file Gravity.ino
+ * @author Adam Wonak (https://github.com/awonak/)
+ * @brief Alt firmware version of Gravity by Sitka Instruments.
+ * @version v2.0.1beta1 - February 2026 awonak
+ * @date 2026-02-21
+ *
+ * @copyright MIT - (c) 2026 - Adam Wonak - adam.wonak@gmail.com
+ *
+ * This version of Gravity firmware is a full rewrite that leverages the
+ * libGravity hardware abstraction library. The goal of this project was to
+ * create an open source friendly version of the firmware that makes it easy
+ * for users/developers to modify and create their own original alt firmware
+ * implementations.
+ *
+ * The libGravity library represents wrappers around the
+ * hardware peripherials to make it easy to interact with and add behavior
+ * to them. The library tries not to make any assumptions about what the
+ * firmware can or should do.
+ *
+ * The Gravity firmware is a slightly different implementation of the original
+ * firmware. There are a few notable changes; the internal clock operates at
+ * 96 PPQN instead of the original 24 PPQN, which allows for more granular
+ * quantization of features like duty cycle (pulse width) or offset.
+ * Additionally, this firmware replaces the sequencer with a Euclidean Rhythm
+ * generator.
+ *
+ * ENCODER:
+ *      Press: change between selecting a parameter and editing the parameter.
+ *      Hold & Rotate: change current selected output channel.
+ *
+ * BTN1:
+ *      Play/pause - start or stop the internal clock.
+ *
+ * BTN2:
+ *      Shift - hold and rotate encoder to change current selected output
+ * channel.
+ *
+ * EXT:
+ *      External clock input. When Gravity is set to INTERNAL or MIDI clock
+ *      source, this input is used to reset clocks.
+ *
+ * CV1:
+ *      External analog input used to provide modulation to any channel
+ * parameter.
+ *
+ * CV2:
+ *      External analog input used to provide modulation to any channel
+ * parameter.
+ *
+ */
+
+#include <libGravity.h>
+
+#include "app_state.h"
+#include "channel.h"
+#include "display.h"
+#include "save_state.h"
+
+AppState app;
+StateManager stateManager;
+
+//
+// Arduino setup and loop.
+//
+
+void setup() {
+  // Start Gravity.
+  gravity.Init();
+
+  // Show bootsplash when initializing firmware.
+  Bootsplash();
+  delay(2000);
+
+  // Initialize the state manager. This will load settings from EEPROM
+  stateManager.initialize(app);
+  InitGravity(app);
+
+  // Clock handlers.
+  gravity.clock.AttachIntHandler(HandleIntClockTick);
+  gravity.clock.AttachExtHandler(HandleExtClockTick);
+
+  // Encoder rotate and press handlers.
+  gravity.encoder.AttachPressHandler(HandleEncoderPressed);
+  gravity.encoder.AttachRotateHandler(HandleRotate);
+  gravity.encoder.AttachPressRotateHandler(HandlePressedRotate);
+
+  // Button press handlers.
+  gravity.play_button.AttachPressHandler(HandlePlayPressed);
+}
+
+void loop() {
+  // Process change in state of inputs and outputs.
+  gravity.Process();
+
+  // Read CVs and call the update function for each channel.
+  int cv1 = gravity.cv1.Read();
+  int cv2 = gravity.cv2.Read();
+
+  for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
+    auto &ch = app.channel[i];
+    // Only apply CV to the channel when the current channel has cv
+    // mod configured.
+    if (ch.isCvModActive()) {
+      ch.applyCvMod(cv1, cv2);
+    }
+  }
+
+  // Clock Run
+  if (app.cv_run == 1 || app.cv_run == 2) {
+    auto &cv = app.cv_run == 1 ? gravity.cv1 : gravity.cv2;
+    int val = cv.Read();
+    if (val > AnalogInput::GATE_THRESHOLD && gravity.clock.IsPaused()) {
+      gravity.clock.Start();
+      app.refresh_screen = true;
+    } else if (val < AnalogInput::GATE_THRESHOLD && !gravity.clock.IsPaused()) {
+      gravity.clock.Stop();
+      ResetOutputs();
+      app.refresh_screen = true;
+    }
+  }
+
+  // Clock Reset
+  if ((app.cv_reset == 1 &&
+       gravity.cv1.IsRisingEdge(AnalogInput::GATE_THRESHOLD)) ||
+      (app.cv_reset == 2 &&
+       gravity.cv2.IsRisingEdge(AnalogInput::GATE_THRESHOLD))) {
+    gravity.clock.Reset();
+  }
+
+  // Check for dirty state eligible to be saved.
+  stateManager.update(app);
+
+  if (app.refresh_screen) {
+    UpdateDisplay();
+  }
+}
+
+//
+// Firmware handlers for clocks.
+//
+
+void HandleIntClockTick(uint32_t tick) {
+  bool refresh = false;
+  for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
+    app.channel[i].processClockTick(tick, gravity.outputs[i]);
+
+    if (app.channel[i].isCvModActive()) {
+      refresh = true;
+    }
+  }
+
+  // Pulse Out gate
+  if (app.selected_pulse != Clock::PULSE_NONE) {
+    int clock_index;
+    switch (app.selected_pulse) {
+    case Clock::PULSE_PPQN_24:
+      clock_index = PULSE_PPQN_24_CLOCK_MOD_INDEX;
+      break;
+    case Clock::PULSE_PPQN_4:
+      clock_index = PULSE_PPQN_4_CLOCK_MOD_INDEX;
+      break;
+    case Clock::PULSE_PPQN_1:
+      clock_index = PULSE_PPQN_1_CLOCK_MOD_INDEX;
+      break;
+    }
+
+    const uint16_t pulse_high_ticks =
+        pgm_read_word_near(&CLOCK_MOD_PULSES[clock_index]);
+    const uint32_t pulse_low_ticks = tick + max((pulse_high_ticks / 2), 1L);
+
+    if (tick % pulse_high_ticks == 0) {
+      gravity.pulse.High();
+    } else if (pulse_low_ticks % pulse_high_ticks == 0) {
+      gravity.pulse.Low();
+    }
+  }
+
+  if (!app.editing_param) {
+    app.refresh_screen |= refresh;
+  }
+}
+
+void HandleExtClockTick() {
+  switch (app.selected_source) {
+  case Clock::SOURCE_INTERNAL:
+  case Clock::SOURCE_EXTERNAL_MIDI:
+    // Use EXT as Reset when not used for clock source.
+    ResetOutputs();
+    gravity.clock.Reset();
+    break;
+  default:
+    // Register EXT cv clock tick.
+    gravity.clock.Tick();
+  }
+  app.refresh_screen = true;
+}
+
+//
+// UI handlers for encoder and buttons.
+//
+
+void HandlePlayPressed() {
+  // Check if SHIFT is pressed to mute all/current channel.
+  if (gravity.shift_button.On()) {
+    if (app.selected_channel == 0) {
+      // Mute all channels
+      for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
+        app.channel[i].toggleMute();
+      }
+    } else {
+      // Mute selected channel
+      auto &ch = GetSelectedChannel();
+      ch.toggleMute();
+    }
+    return;
+  }
+
+  gravity.clock.IsPaused() ? gravity.clock.Start() : gravity.clock.Stop();
+  ResetOutputs();
+  app.refresh_screen = true;
+}
+
+void HandleEncoderPressed() {
+  // Check if leaving editing mode should apply a selection.
+  if (app.editing_param) {
+    if (app.selected_channel == 0) { // main page
+      // TODO: rewrite as switch
+      if (app.selected_param == PARAM_MAIN_ENCODER_DIR) {
+        app.encoder_reversed = app.selected_sub_param == 1;
+        gravity.encoder.SetReverseDirection(app.encoder_reversed);
+      }
+      if (app.selected_param == PARAM_MAIN_ROTATE_DISP) {
+        app.rotate_display = app.selected_sub_param == 1;
+        gravity.display.setFlipMode(app.rotate_display ? 1 : 0);
+      }
+      if (app.selected_param == PARAM_MAIN_SAVE_DATA) {
+        if (app.selected_sub_param < StateManager::MAX_SAVE_SLOTS) {
+          app.selected_save_slot = app.selected_sub_param;
+          stateManager.saveData(app);
+        }
+      }
+      if (app.selected_param == PARAM_MAIN_LOAD_DATA) {
+        if (app.selected_sub_param < StateManager::MAX_SAVE_SLOTS) {
+          app.selected_save_slot = app.selected_sub_param;
+          // Load pattern data into app state.
+          stateManager.loadData(app, app.selected_save_slot);
+          // Load global performance settings if they have changed.
+          if (gravity.clock.Tempo() != app.tempo) {
+            gravity.clock.SetTempo(app.tempo);
+          }
+          // Load global settings only if clock is not active.
+          if (gravity.clock.IsPaused()) {
+            InitGravity(app);
+          }
+        }
+      }
+      if (app.selected_param == PARAM_MAIN_RESET_STATE) {
+        if (app.selected_sub_param == 0) { // Reset
+          stateManager.reset(app);
+          InitGravity(app);
+        }
+      }
+      if (app.selected_param == PARAM_MAIN_FACTORY_RESET) {
+        if (app.selected_sub_param == 0) { // Erase
+          // Show bootsplash during slow erase operation.
+          Bootsplash();
+          stateManager.factoryReset(app);
+          InitGravity(app);
+        }
+      }
+    }
+    // Only mark dirty and reset selected_sub_param when leaving editing mode.
+    stateManager.markDirty();
+    app.selected_sub_param = 0;
+  }
+
+  app.editing_param = !app.editing_param;
+  app.refresh_screen = true;
+}
+
+void HandleRotate(int val) {
+  // Shift & Rotate check
+  if (gravity.shift_button.On()) {
+    HandlePressedRotate(val);
+    return;
+  }
+
+  if (!app.editing_param) {
+    // Navigation Mode
+    const int max_param =
+        (app.selected_channel == 0) ? PARAM_MAIN_LAST : PARAM_CH_LAST;
+    updateSelection(app.selected_param, val, max_param);
+  } else {
+    // Editing Mode
+    if (app.selected_channel == 0) {
+      editMainParameter(val);
+    } else {
+      editChannelParameter(val);
+    }
+  }
+  app.refresh_screen = true;
+}
+
+void HandlePressedRotate(int val) {
+  updateSelection(app.selected_channel, val, Gravity::OUTPUT_COUNT + 1);
+  app.selected_param = 0;
+  stateManager.markDirty();
+  app.refresh_screen = true;
+}
+
+void editMainParameter(int val) {
+  switch (static_cast<ParamsMainPage>(app.selected_param)) {
+  case PARAM_MAIN_TEMPO:
+    if (gravity.clock.ExternalSource()) {
+      break;
+    }
+    gravity.clock.SetTempo(gravity.clock.Tempo() + val);
+    app.tempo = gravity.clock.Tempo();
+    break;
+  case PARAM_MAIN_RUN:
+    updateSelection(app.selected_sub_param, val, 3);
+    app.cv_run = app.selected_sub_param;
+    break;
+  case PARAM_MAIN_RESET:
+    updateSelection(app.selected_sub_param, val, 3);
+    app.cv_reset = app.selected_sub_param;
+    break;
+  case PARAM_MAIN_SOURCE: {
+    byte source = static_cast<int>(app.selected_source);
+    updateSelection(source, val, Clock::SOURCE_LAST);
+    app.selected_source = static_cast<Clock::Source>(source);
+    gravity.clock.SetSource(app.selected_source);
+    break;
+  }
+  case PARAM_MAIN_PULSE: {
+    byte pulse = static_cast<int>(app.selected_pulse);
+    updateSelection(pulse, val, Clock::PULSE_LAST);
+    app.selected_pulse = static_cast<Clock::Pulse>(pulse);
+    if (app.selected_pulse == Clock::PULSE_NONE) {
+      gravity.pulse.Low();
+    }
+    break;
+  }
+  // These changes are applied upon encoder button press.
+  case PARAM_MAIN_ENCODER_DIR:
+    updateSelection(app.selected_sub_param, val, 2);
+    break;
+  case PARAM_MAIN_ROTATE_DISP:
+    updateSelection(app.selected_sub_param, val, 2);
+    break;
+  case PARAM_MAIN_SAVE_DATA:
+  case PARAM_MAIN_LOAD_DATA:
+    updateSelection(app.selected_sub_param, val,
+                    StateManager::MAX_SAVE_SLOTS + 1);
+    break;
+  case PARAM_MAIN_RESET_STATE:
+    updateSelection(app.selected_sub_param, val, 2);
+    break;
+  case PARAM_MAIN_FACTORY_RESET:
+    updateSelection(app.selected_sub_param, val, 2);
+    break;
+  }
+}
+
+void editChannelParameter(int val) {
+  auto &ch = GetSelectedChannel();
+  switch (app.selected_param) {
+  case PARAM_CH_MOD:
+    ch.setClockMod(ch.getClockModIndex() + val);
+    break;
+  case PARAM_CH_EUC_STEPS:
+    ch.setSteps(ch.getSteps() + val);
+    break;
+  case PARAM_CH_EUC_HITS:
+    ch.setHits(ch.getHits() + val);
+    break;
+  case PARAM_CH_CV1_DEST: {
+    byte dest = static_cast<int>(ch.getCv1Dest());
+    updateSelection(dest, val, CV_DEST_LAST);
+    ch.setCv1Dest(static_cast<CvDestination>(dest));
+    break;
+  }
+  case PARAM_CH_CV2_DEST: {
+    byte dest = static_cast<int>(ch.getCv2Dest());
+    updateSelection(dest, val, CV_DEST_LAST);
+    ch.setCv2Dest(static_cast<CvDestination>(dest));
+    break;
+  }
+  }
+}
+
+// Changes the param by the value provided.
+void updateSelection(byte &param, int change, int maxValue) {
+  // Do not apply acceleration if max value is less than 25.
+  if (maxValue < 25) {
+    change = change > 0 ? 1 : -1;
+  }
+  param = constrain(param + change, 0, maxValue - 1);
+}
+
+//
+// App Helper functions.
+//
+
+void InitGravity(AppState &app) {
+  gravity.clock.SetTempo(app.tempo);
+  gravity.clock.SetSource(app.selected_source);
+  gravity.encoder.SetReverseDirection(app.encoder_reversed);
+  gravity.display.setFlipMode(app.rotate_display ? 1 : 0);
+}
+
+void ResetOutputs() {
+  for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
+    gravity.outputs[i].Low();
+  }
+}

firmware/Euclidean/app_state.h

@@ -0,0 +1,44 @@
+/**
+ * @file app_state.h
+ * @author Adam Wonak (https://github.com/awonak/)
+ * @brief Alt firmware version of Gravity by Sitka Instruments.
+ * @version 2.0.1
+ * @date 2025-07-04
+ *
+ * @copyright MIT - (c) 2025 - Adam Wonak - adam.wonak@gmail.com
+ *
+ */
+
+#ifndef APP_STATE_H
+#define APP_STATE_H
+
+#include <libGravity.h>
+
+#include "channel.h"
+
+// Global state for settings and app behavior.
+struct AppState {
+  int tempo = Clock::DEFAULT_TEMPO;
+  Channel channel[Gravity::OUTPUT_COUNT];
+  byte selected_param = 0;
+  byte selected_sub_param = 0; // Temporary value for editing params.
+  byte selected_channel = 0;   // 0=tempo, 1-6=output channel
+  byte selected_swing = 0;
+  byte selected_save_slot = 0; // The currently active save slot.
+  Clock::Source selected_source = Clock::SOURCE_INTERNAL;
+  Clock::Pulse selected_pulse = Clock::PULSE_PPQN_24;
+  byte cv_run = 0;
+  byte cv_reset = 0;
+  bool editing_param = false;
+  bool encoder_reversed = false;
+  bool rotate_display = false;
+  bool refresh_screen = true;
+};
+
+extern AppState app;
+
+static Channel &GetSelectedChannel() {
+  return app.channel[app.selected_channel - 1];
+}
+
+#endif // APP_STATE_H

firmware/Euclidean/channel.h

@@ -0,0 +1,247 @@
+/**
+ * @file channel.h
+ * @author Adam Wonak (https://github.com/awonak/)
+ * @brief Alt firmware version of Gravity by Sitka Instruments.
+ * @version 2.0.1
+ * @date 2025-07-04
+ *
+ * @copyright MIT - (c) 2025 - Adam Wonak - adam.wonak@gmail.com
+ *
+ */
+
+#ifndef CHANNEL_H
+#define CHANNEL_H
+
+#include <Arduino.h>
+#include <libGravity.h>
+
+#include "euclidean.h"
+
+// Enums for CV Mod destination
+enum CvDestination : uint8_t {
+  CV_DEST_NONE,
+  CV_DEST_MOD,
+  CV_DEST_EUC_STEPS,
+  CV_DEST_EUC_HITS,
+  CV_DEST_LAST,
+};
+
+static const byte MOD_CHOICE_SIZE = 25;
+
+// Negative numbers are multipliers, positive are divisors.
+static const int CLOCK_MOD[MOD_CHOICE_SIZE] PROGMEM = {
+    // Divisors
+    128, 64, 32, 24, 16, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2,
+    // Internal Clock Unity (quarter note)
+    1,
+    // Multipliers
+    -2, -3, -4, -6, -8, -12, -16, -24};
+
+// This represents the number of clock pulses for a 96 PPQN clock source
+// that match the above div/mult mods.
+static const int CLOCK_MOD_PULSES[MOD_CHOICE_SIZE] PROGMEM = {
+    // Divisor Pulses (96 * X)
+    12288, 6144, 3072, 2304, 1536, 1152, 1056, 960, 864, 768, 672, 576, 480,
+    384, 288, 192,
+    // Internal Clock Pulses
+    96,
+    // Multiplier Pulses (96 / X)
+    48, 32, 24, 16, 12, 8, 6, 4};
+
+static const byte DEFAULT_CLOCK_MOD_INDEX = 16; // x1 or 96 PPQN.
+
+static const byte PULSE_PPQN_24_CLOCK_MOD_INDEX = MOD_CHOICE_SIZE - 1;
+static const byte PULSE_PPQN_4_CLOCK_MOD_INDEX = MOD_CHOICE_SIZE - 6;
+static const byte PULSE_PPQN_1_CLOCK_MOD_INDEX = MOD_CHOICE_SIZE - 9;
+
+class Channel {
+public:
+  Channel() { Init(); }
+
+  void Init() {
+    // Reset base values to their defaults
+    base_clock_mod_index = DEFAULT_CLOCK_MOD_INDEX;
+    base_euc_steps = 1;
+    base_euc_hits = 1;
+
+    cvmod_clock_mod_index = base_clock_mod_index;
+
+    cv1_dest = CV_DEST_NONE;
+    cv2_dest = CV_DEST_NONE;
+
+    pattern.Init(DEFAULT_PATTERN);
+
+    // Calcule the clock mod pulses on init.
+    _recalculatePulses();
+  }
+
+  // Setters (Set the BASE value)
+
+  void setClockMod(int index) {
+    base_clock_mod_index = constrain(index, 0, MOD_CHOICE_SIZE - 1);
+    if (!isCvModActive()) {
+      cvmod_clock_mod_index = base_clock_mod_index;
+      _recalculatePulses();
+    }
+  }
+
+  // Euclidean
+  void setSteps(int val) {
+    base_euc_steps = constrain(val, 1, MAX_PATTERN_LEN);
+    if (cv1_dest != CV_DEST_EUC_STEPS && cv2_dest != CV_DEST_EUC_STEPS) {
+      pattern.SetSteps(val);
+    }
+  }
+  void setHits(int val) {
+    base_euc_hits = constrain(val, 1, base_euc_steps);
+    if (cv1_dest != CV_DEST_EUC_HITS && cv2_dest != CV_DEST_EUC_HITS) {
+      pattern.SetHits(val);
+    }
+  }
+
+  void setCv1Dest(CvDestination dest) { cv1_dest = dest; }
+  void setCv2Dest(CvDestination dest) { cv2_dest = dest; }
+  CvDestination getCv1Dest() const { return cv1_dest; }
+  CvDestination getCv2Dest() const { return cv2_dest; }
+
+  // Getters (Get the BASE value for editing or cv modded value for display)
+
+  int getClockMod(bool withCvMod = false) const {
+    return pgm_read_word_near(&CLOCK_MOD[getClockModIndex(withCvMod)]);
+  }
+  int getClockModIndex(bool withCvMod = false) const {
+    return withCvMod ? cvmod_clock_mod_index : base_clock_mod_index;
+  }
+  bool isCvModActive() const {
+    return cv1_dest != CV_DEST_NONE || cv2_dest != CV_DEST_NONE;
+  }
+
+  byte getSteps(bool withCvMod = false) const {
+    return withCvMod ? pattern.GetSteps() : base_euc_steps;
+  }
+  byte getHits(bool withCvMod = false) const {
+    return withCvMod ? pattern.GetHits() : base_euc_hits;
+  }
+
+  void toggleMute() { mute = !mute; }
+
+  /**
+   * @brief Processes a clock tick and determines if the output should be high
+   * or low. Note: this method is called from an ISR and must be kept as simple
+   * as possible.
+   * @param tick The current clock tick count.
+   * @param output The output object to be modified.
+   */
+  void processClockTick(uint32_t tick, DigitalOutput &output) {
+    // Mute check
+    if (mute) {
+      output.Low();
+      return;
+    }
+
+    const uint16_t mod_pulses =
+        pgm_read_word_near(&CLOCK_MOD_PULSES[cvmod_clock_mod_index]);
+
+    // Euclidian rhythm cycle check
+    if (!output.On()) {
+      // Step check
+      if (tick % mod_pulses == 0) {
+        bool hit = true;
+        // Euclidean rhythm hit check
+        switch (pattern.NextStep()) {
+        case Pattern::REST:
+          hit = false;
+          break;
+        case Pattern::HIT:
+          hit &= true;
+          break;
+        }
+        if (hit) {
+          output.High();
+        }
+      }
+    }
+
+    // Output low check. Half pulse width.
+    const uint32_t duty_cycle_end_tick = tick + _duty_pulses;
+    if (duty_cycle_end_tick % mod_pulses == 0) {
+      output.Low();
+    }
+  }
+  /**
+   * @brief Calculate and store cv modded values using bipolar mapping.
+   * Default to base value if not the current CV destination.
+   *
+   * @param cv1_val analog input reading for cv1
+   * @param cv2_val analog input reading for cv2
+   *
+   */
+  void applyCvMod(int cv1_val, int cv2_val) {
+    // Note: This is optimized for cpu performance. This method is called
+    // from the main loop and stores the cv mod values. This reduces CPU
+    // cycles inside the internal clock interrupt, which is preferrable.
+    // However, if RAM usage grows too much, we have an opportunity to
+    // refactor this to store just the CV read values, and calculate the
+    // cv mod value per channel inside the getter methods by passing cv
+    // values. This would reduce RAM usage, but would introduce a
+    // significant CPU cost, which may have undesirable performance issues.
+    if (!isCvModActive()) {
+      cvmod_clock_mod_index = base_clock_mod_index;
+      return;
+    }
+
+    int dest_mod = _calculateMod(CV_DEST_MOD, cv1_val, cv2_val,
+                                 -(MOD_CHOICE_SIZE / 2), MOD_CHOICE_SIZE / 2);
+    cvmod_clock_mod_index = constrain(base_clock_mod_index + dest_mod, 0, 100);
+
+    int step_mod =
+        _calculateMod(CV_DEST_EUC_STEPS, cv1_val, cv2_val, 0, MAX_PATTERN_LEN);
+    pattern.SetSteps(base_euc_steps + step_mod);
+
+    int hit_mod = _calculateMod(CV_DEST_EUC_HITS, cv1_val, cv2_val, 0,
+                                pattern.GetSteps());
+    pattern.SetHits(base_euc_hits + hit_mod);
+
+    // After all cvmod values are updated, recalculate clock pulse modifiers.
+    _recalculatePulses();
+  }
+
+private:
+  int _calculateMod(CvDestination dest, int cv1_val, int cv2_val, int min_range,
+                    int max_range) {
+    int mod1 =
+        (cv1_dest == dest) ? map(cv1_val, -512, 512, min_range, max_range) : 0;
+    int mod2 =
+        (cv2_dest == dest) ? map(cv2_val, -512, 512, min_range, max_range) : 0;
+    return mod1 + mod2;
+  }
+
+  void _recalculatePulses() {
+    const uint16_t mod_pulses =
+        pgm_read_word_near(&CLOCK_MOD_PULSES[cvmod_clock_mod_index]);
+    _duty_pulses = max((long)(mod_pulses / 2L), 1L);
+  }
+
+  // User-settable base values.
+  byte base_clock_mod_index;
+  byte base_euc_steps;
+  byte base_euc_hits;
+
+  // Base value with cv mod applied.
+  byte cvmod_clock_mod_index;
+
+  // CV mod configuration
+  CvDestination cv1_dest;
+  CvDestination cv2_dest;
+
+  // Euclidean pattern
+  Pattern pattern;
+
+  // Mute channel flag
+  bool mute;
+
+  // Pre-calculated pulse values for ISR performance
+  uint16_t _duty_pulses;
+};
+
+#endif // CHANNEL_H

firmware/Euclidean/display.h

@@ -0,0 +1,519 @@
+/**
+ * @file display.h
+ * @author Adam Wonak (https://github.com/awonak/)
+ * @brief Alt firmware version of Gravity by Sitka Instruments.
+ * @version 2.0.1
+ * @date 2025-07-04
+ *
+ * @copyright MIT - (c) 2025 - Adam Wonak - adam.wonak@gmail.com
+ *
+ */
+
+#ifndef DISPLAY_H
+#define DISPLAY_H
+
+#include <Arduino.h>
+
+#include "app_state.h"
+#include "save_state.h"
+
+//
+// UI Display functions for drawing the UI to the OLED display.
+//
+
+/*
+ * Font: velvetscreen.bdf 9pt
+ * https://stncrn.github.io/u8g2-unifont-helper/
+ * "%/0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+ */
+const uint8_t TEXT_FONT[437] U8G2_FONT_SECTION("velvetscreen") PROGMEM =
+    "\64\0\2\2\3\3\2\3\4\5\5\0\0\5\0\5\0\0\221\0\0\1\230 \4\200\134%\11\255tT"
+    "R\271RI(\6\252\334T\31)\7\252\134bJ\12+\7\233\345\322J\0,\5\221T\4-\5\213"
+    "f\6.\5\211T\2/"
+    "\6\244\354c\33\60\10\254\354T\64\223\2\61\7\353\354\222\254\6\62\11\254l"
+    "\66J*"
+    "\217\0\63\11\254l\66J\32\215\4\64\10\254l\242\34\272\0\65\11\254l\206\336h"
+    "$\0\66"
+    "\11\254\354T^\61)\0\67\10\254lF\216u\4\70\11\254\354TL*&"
+    "\5\71\11\254\354TL;"
+    ")\0:\6\231UR\0A\10\254\354T\34S\6B\11\254lV\34)\216\4C\11\254\354T\324\61"
+    ")\0D\10\254lV\64G\2E\10\254l\206\36z\4F\10\254l\206^\71\3G\11\254\354TN"
+    "\63)"
+    "\0H\10\254l\242\34S\6I\6\251T\206\0J\10\254\354k\231\24\0K\11\254l\242J\62"
+    "\225\1L\7\254lr{\4M\11\255t\362ZI\353\0N\11\255t\362TI\356\0O\10\254\354T"
+    "\64\223\2P\11\254lV\34)"
+    "g\0Q\10\254\354T\264b\12R\10\254lV\34\251\31S\11\254\354"
+    "FF\32\215\4T\7\253dVl\1U\10\254l\242\63)\0V\11\255t\262Ne\312\21W\12\255"
+    "t\262J*\251.\0X\11\254l\242L*\312\0Y\12\255tr\252\63\312(\2Z\7\253df*"
+    "\7p\10\255\364V\266\323\2q\7\255\364\216\257\5r\10\253d\242\32*"
+    "\2t\6\255t\376#w\11"
+    "\255\364V\245FN\13x\6\233dR\7\0\0\0\4\377\377\0";
+
+/*
+ * Font: STK-L.bdf 36pt
+ * https://stncrn.github.io/u8g2-unifont-helper/
+ * "%/0123456789ABCDEFILNORSTUVXx"
+ */
+const uint8_t LARGE_FONT[766] U8G2_FONT_SECTION("stk-l") =
+    "\35\0\4\4\4\5\3\1\6\20\30\0\0\27\0\0\0\1\77\0\0\2\341%'\17;\226\261\245FL"
+    "\64B\214\30\22\223\220)"
+    "Bj\10Q\232\214\42R\206\310\210\21d\304\30\32a\254\304\270!\0/\14"
+    "\272\272\275\311H\321g\343\306\1\60\37|\373\35CJT\20:"
+    "fW\207\320\210\60\42\304\204\30D\247"
+    "\214\331\354\20\11%"
+    "\212\314\0\61\24z\275\245a\244\12\231\71\63b\214\220q\363\377(E\6\62\33|"
+    "\373\35ShT\20:fl\344\14\211\231\301\306T\71\202#g\371\340\201\1\63\34|"
+    "\373\35ShT"
+    "\20:fl\344@r\264\263\222\344,\215\35\42\241\6\225\31\0\64 "
+    "|\373-!\203\206\214!\62\204"
+    "\314\220A#\10\215\30\65b\324\210Q\306\354\354\1\213\225\363\1\65\32|"
+    "\373\15\25[\214\234/\10)"
+    "Y\61j\350\310Y\32;DB\15*\63\0\66\33}\33\236SiV\14;gt^\230Y\302\202\324"
+    "\71\273;EbM\252\63\0\67\23|\373\205\25\17R\316\207\344\350p\312\201#"
+    "\347\35\0\70 |\373"
+    "\35ShT\20:f\331!\22D\310 "
+    ":\205\206\10\11B\307\354\354\20\11\65\250\314\0\71\32|\373"
+    "\35ShT\20:fg\207H,Q\223r\276\30DB\15*\63\0A\26}\33\246r\247\322P\62"
+    "j\310\250\21\343\354\335\203\357\354w\3B$}"
+    "\33\206Dj\226\214\42\61l\304\260\21\303F\14\33\61"
+    "\212\304\222MF\221\30v\316\236=\10\301b\11\0C\27}"
+    "\33\236Si\226\20Bft\376O\211\215"
+    " Db\215\42$\0D\33}\33\206Dj\226\214\32\62l\304\260\21\343\354\177vl\304("
+    "\22K\324"
+    "$\2E\22|\373\205\17R\316KD\30\215\234_>x`\0F\20|"
+    "\373\205\17R\316\227i\262\31"
+    "\71\377\22\0I\7s\333\204\77HL\15{\333\205\201\363\377\77|\360`\0N$}"
+    "\33\6\201\346\314"
+    "\35;\206\12U\242D&\306\230\30cd\210\221!fF\230\31a(+\314\256\63\67\0O\26}"
+    "\33"
+    "\236Si\226\214\32\61\316\376\277\33\61j\310\232Tg\0R\61\216;\6Ek\230\14#"
+    "\61n\304\270"
+    "\21\343F\214\33\61n\304\60\22\243\210\60Q\224j\310\260\61\243\306\20\232"
+    "\325\230QD\206\221\30\67b"
+    "\334\301\1S\42\216;\236c\211\226\220\42\61n\304\270\21c\307R\232,["
+    "\262\203\307\216\65h\16\25"
+    "\21&\253\320\0T\15}\33\206\17R\15\235\377\377\25\0U\21|"
+    "\373\205a\366\377\237\215\30\64D\15"
+    "*\63\0V\26\177\371\205\221\366\377\313\21\343\206\220\42C\25\11r'"
+    "\313\16\3X)~;\206\201\6"
+    "\217\221\30\66\204\20\31\42\244\206\14Cg\320$Q\222\6\315!"
+    "\33\62\212\10\31BD\206\215 v\320"
+    "\302\1x\24\312\272\205A\206\216\220@c\212\224\31$"
+    "S\14\262h\0\0\0\0\4\377\377\0";
+
+#define play_icon_width 14
+#define play_icon_height 14
+static const unsigned char play_icon[28] PROGMEM = {
+    0x00, 0x00, 0x00, 0x00, 0x3C, 0x00, 0x7C, 0x00, 0xFC, 0x00,
+    0xFC, 0x03, 0xFC, 0x0F, 0xFC, 0x0F, 0xFC, 0x03, 0xFC, 0x00,
+    0x7C, 0x00, 0x3C, 0x00, 0x00, 0x00, 0x00, 0x00};
+static const unsigned char pause_icon[28] PROGMEM = {
+    0x00, 0x00, 0x00, 0x00, 0x38, 0x0E, 0x38, 0x0E, 0x38, 0x0E,
+    0x38, 0x0E, 0x38, 0x0E, 0x38, 0x0E, 0x38, 0x0E, 0x38, 0x0E,
+    0x38, 0x0E, 0x38, 0x0E, 0x38, 0x0E, 0x00, 0x00};
+
+// Constants for screen layout and fonts
+constexpr uint8_t SCREEN_CENTER_X = 32;
+constexpr uint8_t MAIN_TEXT_Y = 26;
+constexpr uint8_t SUB_TEXT_Y = 40;
+constexpr uint8_t VISIBLE_MENU_ITEMS = 3;
+constexpr uint8_t MENU_ITEM_HEIGHT = 14;
+constexpr uint8_t MENU_BOX_PADDING = 4;
+constexpr uint8_t MENU_BOX_WIDTH = 64;
+constexpr uint8_t CHANNEL_BOXES_Y = 50;
+constexpr uint8_t CHANNEL_BOX_WIDTH = 18;
+constexpr uint8_t CHANNEL_BOX_HEIGHT = 14;
+
+// Menu items for editing global parameters.
+enum ParamsMainPage : uint8_t {
+  PARAM_MAIN_TEMPO,
+  PARAM_MAIN_RUN,
+  PARAM_MAIN_RESET,
+  PARAM_MAIN_SOURCE,
+  PARAM_MAIN_PULSE,
+  PARAM_MAIN_ENCODER_DIR,
+  PARAM_MAIN_ROTATE_DISP,
+  PARAM_MAIN_SAVE_DATA,
+  PARAM_MAIN_LOAD_DATA,
+  PARAM_MAIN_RESET_STATE,
+  PARAM_MAIN_FACTORY_RESET,
+  PARAM_MAIN_LAST,
+};
+
+// Menu items for editing channel parameters.
+enum ParamsChannelPage : uint8_t {
+  PARAM_CH_MOD,
+  PARAM_CH_EUC_STEPS,
+  PARAM_CH_EUC_HITS,
+  PARAM_CH_CV1_DEST,
+  PARAM_CH_CV2_DEST,
+  PARAM_CH_LAST,
+};
+
+// Helper function to draw centered text
+void drawCenteredText(const char *text, int y, const uint8_t *font) {
+  gravity.display.setFont(font);
+  int textWidth = gravity.display.getStrWidth(text);
+  gravity.display.drawStr(SCREEN_CENTER_X - (textWidth / 2), y, text);
+}
+
+// Helper function to draw right-aligned text
+void drawRightAlignedText(const char *text, int y) {
+  int textWidth = gravity.display.getStrWidth(text);
+  int drawX = (SCREEN_WIDTH - textWidth) - MENU_BOX_PADDING;
+  gravity.display.drawStr(drawX, y, text);
+}
+
+void drawMainSelection() {
+  gravity.display.setDrawColor(1);
+  const int tickSize = 3;
+  const int mainWidth = SCREEN_WIDTH / 2;
+  const int mainHeight = 49;
+  gravity.display.drawLine(0, 0, tickSize, 0);
+  gravity.display.drawLine(0, 0, 0, tickSize);
+  gravity.display.drawLine(mainWidth, 0, mainWidth - tickSize, 0);
+  gravity.display.drawLine(mainWidth, 0, mainWidth, tickSize);
+  gravity.display.drawLine(mainWidth, mainHeight, mainWidth,
+                           mainHeight - tickSize);
+  gravity.display.drawLine(mainWidth, mainHeight, mainWidth - tickSize,
+                           mainHeight);
+  gravity.display.drawLine(0, mainHeight, tickSize, mainHeight);
+  gravity.display.drawLine(0, mainHeight, 0, mainHeight - tickSize);
+  gravity.display.setDrawColor(2);
+}
+
+void drawMenuItems(String menu_items[], int menu_size) {
+  // Draw menu items
+  gravity.display.setFont(TEXT_FONT);
+
+  // Draw selected menu item box
+  int selectedBoxY = 0;
+  if (menu_size >= VISIBLE_MENU_ITEMS && app.selected_param == menu_size - 1) {
+    selectedBoxY = MENU_ITEM_HEIGHT * min(2, app.selected_param);
+  } else if (app.selected_param > 0) {
+    selectedBoxY = MENU_ITEM_HEIGHT;
+  }
+
+  int boxX = MENU_BOX_WIDTH + 1;
+  int boxY = selectedBoxY + 2;
+  int boxWidth = MENU_BOX_WIDTH - 1;
+  int boxHeight = MENU_ITEM_HEIGHT + 1;
+
+  if (app.editing_param) {
+    gravity.display.drawBox(boxX, boxY, boxWidth, boxHeight);
+    drawMainSelection();
+  } else {
+    gravity.display.drawFrame(boxX, boxY, boxWidth, boxHeight);
+  }
+
+  // Draw the visible menu items
+  int start_index = 0;
+  if (menu_size >= VISIBLE_MENU_ITEMS && app.selected_param == menu_size - 1) {
+    start_index = menu_size - VISIBLE_MENU_ITEMS;
+  } else if (app.selected_param > 0) {
+    start_index = app.selected_param - 1;
+  }
+
+  for (int i = 0; i < min(menu_size, VISIBLE_MENU_ITEMS); ++i) {
+    int idx = start_index + i;
+    drawRightAlignedText(menu_items[idx].c_str(),
+                         MENU_ITEM_HEIGHT * (i + 1) - 1);
+  }
+}
+
+// Visual indicators for main section of screen.
+inline void solidTick() { gravity.display.drawBox(56, 4, 4, 4); }
+inline void hollowTick() { gravity.display.drawBox(56, 4, 4, 4); }
+
+// Human friendly display value for save slot.
+String displaySaveSlot(int slot) {
+  if (slot >= 0 && slot < StateManager::MAX_SAVE_SLOTS / 2) {
+    return String("A") + String(slot + 1);
+  } else if (slot >= StateManager::MAX_SAVE_SLOTS / 2 &&
+             slot <= StateManager::MAX_SAVE_SLOTS) {
+    return String("B") + String(slot - (StateManager::MAX_SAVE_SLOTS / 2) + 1);
+  }
+}
+
+// Main display functions
+
+void DisplayMainPage() {
+  gravity.display.setFontMode(1);
+  gravity.display.setDrawColor(2);
+  gravity.display.setFont(TEXT_FONT);
+
+  // Display selected editable value
+  String mainText;
+  String subText;
+
+  switch (app.selected_param) {
+  case PARAM_MAIN_TEMPO:
+    // Serial MIDI is too unstable to display bpm in real time.
+    if (app.selected_source == Clock::SOURCE_EXTERNAL_MIDI) {
+      mainText = F("EXT");
+    } else {
+      mainText = String(gravity.clock.Tempo());
+    }
+    subText = F("BPM");
+    break;
+  case PARAM_MAIN_RUN:
+    mainText = F("RUN");
+    switch (app.cv_run) {
+    case 0:
+      subText = F("NONE");
+      break;
+    case 1:
+      subText = F("CV1 GATE");
+      break;
+    case 2:
+      subText = F("CV2 GATE");
+      break;
+    }
+    break;
+  case PARAM_MAIN_RESET:
+    mainText = F("RST");
+    switch (app.cv_reset) {
+    case 0:
+      subText = F("NONE");
+      break;
+    case 1:
+      subText = F("CV1 TRIG");
+      break;
+    case 2:
+      subText = F("CV2 TRIG");
+      break;
+    }
+    break;
+  case PARAM_MAIN_SOURCE:
+    mainText = F("EXT");
+    switch (app.selected_source) {
+    case Clock::SOURCE_INTERNAL:
+      mainText = F("INT");
+      subText = F("CLOCK");
+      break;
+    case Clock::SOURCE_EXTERNAL_PPQN_24:
+      subText = F("24 PPQN");
+      break;
+    case Clock::SOURCE_EXTERNAL_PPQN_4:
+      subText = F("4 PPQN");
+      break;
+    case Clock::SOURCE_EXTERNAL_PPQN_2:
+      subText = F("2 PPQN");
+      break;
+    case Clock::SOURCE_EXTERNAL_PPQN_1:
+      subText = F("1 PPQN");
+      break;
+    case Clock::SOURCE_EXTERNAL_MIDI:
+      subText = F("MIDI");
+      break;
+    }
+    break;
+  case PARAM_MAIN_PULSE:
+    mainText = F("OUT");
+    switch (app.selected_pulse) {
+    case Clock::PULSE_NONE:
+      subText = F("PULSE OFF");
+      break;
+    case Clock::PULSE_PPQN_24:
+      subText = F("24 PPQN PULSE");
+      break;
+    case Clock::PULSE_PPQN_4:
+      subText = F("4 PPQN PULSE");
+      break;
+    case Clock::PULSE_PPQN_1:
+      subText = F("1 PPQN PULSE");
+      break;
+    }
+    break;
+  case PARAM_MAIN_ENCODER_DIR:
+    mainText = F("DIR");
+    subText = app.selected_sub_param == 0 ? F("DEFAULT") : F("REVERSED");
+    break;
+  case PARAM_MAIN_ROTATE_DISP:
+    mainText = F("DISP");
+    subText = app.selected_sub_param == 0 ? F("DEFAULT") : F("ROTATED");
+    break;
+  case PARAM_MAIN_SAVE_DATA:
+  case PARAM_MAIN_LOAD_DATA:
+    if (app.selected_sub_param == StateManager::MAX_SAVE_SLOTS) {
+      mainText = F("x");
+      subText = F("BACK TO MAIN");
+    } else {
+      // Indicate currently active slot.
+      if (app.selected_sub_param == app.selected_save_slot) {
+        solidTick();
+      }
+      mainText = displaySaveSlot(app.selected_sub_param);
+      subText = (app.selected_param == PARAM_MAIN_SAVE_DATA)
+                    ? F("SAVE TO SLOT")
+                    : F("LOAD FROM SLOT");
+    }
+    break;
+  case PARAM_MAIN_RESET_STATE:
+    if (app.selected_sub_param == 0) {
+      mainText = F("RST");
+      subText = F("RESET ALL");
+    } else {
+      mainText = F("x");
+      subText = F("BACK TO MAIN");
+    }
+    break;
+  case PARAM_MAIN_FACTORY_RESET:
+    if (app.selected_sub_param == 0) {
+      mainText = F("DEL");
+      subText = F("FACTORY RESET");
+    } else {
+      mainText = F("x");
+      subText = F("BACK TO MAIN");
+    }
+    break;
+  }
+
+  drawCenteredText(mainText.c_str(), MAIN_TEXT_Y, LARGE_FONT);
+  drawCenteredText(subText.c_str(), SUB_TEXT_Y, TEXT_FONT);
+
+  // Draw Main Page menu items
+  String menu_items[PARAM_MAIN_LAST] = {
+      F("TEMPO"),     F("RUN"),         F("RST"),         F("SOURCE"),
+      F("PULSE OUT"), F("ENCODER DIR"), F("ROTATE DISP"), F("SAVE"),
+      F("LOAD"),      F("RESET"),       F("ERASE")};
+  drawMenuItems(menu_items, PARAM_MAIN_LAST);
+}
+
+void DisplayChannelPage() {
+  auto &ch = GetSelectedChannel();
+
+  gravity.display.setFontMode(1);
+  gravity.display.setDrawColor(2);
+
+  // Display selected editable value
+  String mainText;
+  String subText;
+
+  // When editing a param, just show the base value. When not editing show
+  // the value with cv mod.
+  bool withCvMod = !app.editing_param;
+
+  switch (app.selected_param) {
+  case PARAM_CH_MOD: {
+    int mod_value = ch.getClockMod(withCvMod);
+    if (mod_value > 1) {
+      mainText = F("/");
+      mainText += String(mod_value);
+      subText = F("DIVIDE");
+    } else {
+      mainText = F("x");
+      mainText += String(abs(mod_value));
+      subText = F("MULTIPLY");
+    }
+    break;
+  }
+
+  case PARAM_CH_EUC_STEPS:
+    mainText = String(ch.getSteps(withCvMod));
+    subText = "EUCLID STEPS";
+    break;
+  case PARAM_CH_EUC_HITS:
+    mainText = String(ch.getHits(withCvMod));
+    subText = "EUCLID HITS";
+    break;
+  case PARAM_CH_CV1_DEST:
+  case PARAM_CH_CV2_DEST: {
+    mainText = (app.selected_param == PARAM_CH_CV1_DEST) ? F("CV1") : F("CV2");
+    switch ((app.selected_param == PARAM_CH_CV1_DEST) ? ch.getCv1Dest()
+                                                      : ch.getCv2Dest()) {
+    case CV_DEST_NONE:
+      subText = F("NONE");
+      break;
+    case CV_DEST_MOD:
+      subText = F("CLOCK MOD");
+      break;
+
+    case CV_DEST_EUC_STEPS:
+      subText = F("EUCLID STEPS");
+      break;
+    case CV_DEST_EUC_HITS:
+      subText = F("EUCLID HITS");
+      break;
+    }
+    break;
+  }
+  }
+
+  drawCenteredText(mainText.c_str(), MAIN_TEXT_Y, LARGE_FONT);
+  drawCenteredText(subText.c_str(), SUB_TEXT_Y, TEXT_FONT);
+
+  // Draw Channel Page menu items
+  String menu_items[PARAM_CH_LAST] = {F("MOD"), F("EUCLID STEPS"),
+                                      F("EUCLID HITS"), F("CV1 MOD"),
+                                      F("CV2 MOD")};
+  drawMenuItems(menu_items, PARAM_CH_LAST);
+}
+
+void DisplaySelectedChannel() {
+  int boxX = CHANNEL_BOX_WIDTH;
+  int boxY = CHANNEL_BOXES_Y;
+  int boxWidth = CHANNEL_BOX_WIDTH;
+  int boxHeight = CHANNEL_BOX_HEIGHT;
+  int textOffset = 7; // Half of font width
+
+  // Draw top and right side of frame.
+  gravity.display.drawHLine(1, boxY, SCREEN_WIDTH - 2);
+  gravity.display.drawVLine(SCREEN_WIDTH - 2, boxY, boxHeight);
+
+  for (int i = 0; i < Gravity::OUTPUT_COUNT + 1; i++) {
+    // Draw box frame or filled selected box.
+    gravity.display.setDrawColor(1);
+    (app.selected_channel == i)
+        ? gravity.display.drawBox(i * boxWidth, boxY, boxWidth, boxHeight)
+        : gravity.display.drawVLine(i * boxWidth, boxY, boxHeight);
+
+    // Draw clock status icon or each channel number.
+    gravity.display.setDrawColor(2);
+    if (i == 0) {
+      gravity.display.setBitmapMode(1);
+      auto icon = gravity.clock.IsPaused() ? pause_icon : play_icon;
+      gravity.display.drawXBMP(2, boxY, play_icon_width, play_icon_height,
+                               icon);
+    } else {
+      gravity.display.setFont(TEXT_FONT);
+      gravity.display.setCursor((i * boxWidth) + textOffset, SCREEN_HEIGHT - 3);
+      gravity.display.print(i);
+    }
+  }
+}
+
+void UpdateDisplay() {
+  app.refresh_screen = false;
+  gravity.display.firstPage();
+  do {
+    if (app.selected_channel == 0) {
+      DisplayMainPage();
+    } else {
+      DisplayChannelPage();
+    }
+    // Global channel select UI.
+    DisplaySelectedChannel();
+  } while (gravity.display.nextPage());
+}
+
+void Bootsplash() {
+  gravity.display.firstPage();
+  do {
+    int textWidth;
+    String loadingText = F("LOADING....");
+    gravity.display.setFont(TEXT_FONT);
+
+    textWidth = gravity.display.getStrWidth(StateManager::SKETCH_NAME);
+    gravity.display.drawStr(4 + (textWidth / 2), 22, StateManager::SKETCH_NAME);
+
+    textWidth = gravity.display.getStrWidth(StateManager::SEMANTIC_VERSION);
+    gravity.display.drawStr(16 + (textWidth / 2), 32,
+                            StateManager::SEMANTIC_VERSION);
+
+    textWidth = gravity.display.getStrWidth(loadingText.c_str());
+    gravity.display.drawStr(26 + (textWidth / 2), 44, loadingText.c_str());
+  } while (gravity.display.nextPage());
+}
+
+#endif // DISPLAY_H

firmware/Euclidean/save_state.cpp

@@ -0,0 +1,237 @@
+/**
+ * @file save_state.cpp
+ * @author Adam Wonak (https://github.com/awonak/)
+ * @brief Alt firmware version of Gravity by Sitka Instruments.
+ * @version 2.0.1
+ * @date 2025-07-04
+ *
+ * @copyright MIT - (c) 2025 - Adam Wonak - adam.wonak@gmail.com
+ *
+ */
+
+#include "save_state.h"
+
+#include <EEPROM.h>
+
+#include "app_state.h"
+
+// Define the constants for the current firmware.
+const char StateManager::SKETCH_NAME[] = "ALT EUCLIDEAN";
+const char StateManager::SEMANTIC_VERSION[] =
+    "V2.0.1BETA1"; // NOTE: This should match the version in the
+                   // library.properties file.
+
+// Number of available save slots.
+const byte StateManager::MAX_SAVE_SLOTS = 10;
+const byte StateManager::TRANSIENT_SLOT = 10;
+
+// Define the minimum amount of time between EEPROM writes.
+const unsigned long StateManager::SAVE_DELAY_MS = 2000;
+
+// Calculate the starting address for EepromData, leaving space for metadata.
+const int StateManager::METADATA_START_ADDR = 0;
+const int StateManager::EEPROM_DATA_START_ADDR = sizeof(StateManager::Metadata);
+
+StateManager::StateManager() : _isDirty(false), _lastChangeTime(0) {}
+
+bool StateManager::initialize(AppState &app) {
+  noInterrupts();
+  bool success = false;
+  if (_isDataValid()) {
+    // Load global settings.
+    _loadMetadata(app);
+    // Load app data from the transient slot.
+    _loadState(app, TRANSIENT_SLOT);
+    success = true;
+  }
+  // EEPROM does not contain save data for this firmware & version.
+  else {
+    // Erase EEPROM and initialize state. Save default pattern to all save
+    // slots.
+    factoryReset(app);
+  }
+  interrupts();
+  return success;
+}
+
+bool StateManager::loadData(AppState &app, byte slot_index) {
+  // Check if slot_index is within max range + 1 for transient.
+  if (slot_index >= MAX_SAVE_SLOTS + 1)
+    return false;
+
+  noInterrupts();
+
+  // Load the state data from the specified EEPROM slot and update the app state
+  // save slot.
+  _loadState(app, slot_index);
+  app.selected_save_slot = slot_index;
+  // Persist this change in the global metadata on next update.
+  _isDirty = true;
+
+  interrupts();
+  return true;
+}
+
+// Save app state to user specified save slot.
+void StateManager::saveData(const AppState &app) {
+  noInterrupts();
+  // Check if slot_index is within max range + 1 for transient.
+  if (app.selected_save_slot >= MAX_SAVE_SLOTS + 1) {
+    interrupts();
+    return;
+  }
+
+  _saveState(app, app.selected_save_slot);
+  _saveMetadata(app);
+  _isDirty = false;
+  interrupts();
+}
+
+// Save transient state if it has changed and enough time has passed since last
+// save.
+void StateManager::update(const AppState &app) {
+  if (_isDirty && (millis() - _lastChangeTime > SAVE_DELAY_MS)) {
+    noInterrupts();
+    _saveState(app, TRANSIENT_SLOT);
+    _saveMetadata(app);
+    _isDirty = false;
+    interrupts();
+  }
+}
+
+void StateManager::reset(AppState &app) {
+  noInterrupts();
+
+  AppState default_app;
+  app.tempo = default_app.tempo;
+  app.selected_param = default_app.selected_param;
+  app.selected_channel = default_app.selected_channel;
+  app.selected_source = default_app.selected_source;
+  app.selected_pulse = default_app.selected_pulse;
+  app.cv_run = default_app.cv_run;
+  app.cv_reset = default_app.cv_reset;
+
+  for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
+    app.channel[i].Init();
+  }
+
+  // Load global settings from Metadata
+  _loadMetadata(app);
+
+  _isDirty = false;
+  interrupts();
+}
+
+void StateManager::markDirty() {
+  _isDirty = true;
+  _lastChangeTime = millis();
+}
+
+// Erases all data in the EEPROM by writing 0 to every address.
+void StateManager::factoryReset(AppState &app) {
+  noInterrupts();
+  for (unsigned int i = 0; i < EEPROM.length(); i++) {
+    EEPROM.write(i, 0);
+  }
+  // Initialize eeprom and save default patter to all save slots.
+  _saveMetadata(app);
+  reset(app);
+  for (int i = 0; i < MAX_SAVE_SLOTS; i++) {
+    app.selected_save_slot = i;
+    _saveState(app, i);
+  }
+  _saveState(app, TRANSIENT_SLOT);
+  interrupts();
+}
+
+bool StateManager::_isDataValid() {
+  Metadata metadata;
+  EEPROM.get(METADATA_START_ADDR, metadata);
+  bool name_match = (strcmp(metadata.sketch_name, SKETCH_NAME) == 0);
+  bool version_match = (strcmp(metadata.version, SEMANTIC_VERSION) == 0);
+  return name_match && version_match;
+}
+
+void StateManager::_saveState(const AppState &app, byte slot_index) {
+  // Check if slot_index is within max range + 1 for transient.
+  if (app.selected_save_slot >= MAX_SAVE_SLOTS + 1)
+    return;
+
+  static EepromData save_data;
+
+  save_data.tempo = app.tempo;
+  save_data.selected_param = app.selected_param;
+  save_data.selected_channel = app.selected_channel;
+  save_data.selected_source = static_cast<byte>(app.selected_source);
+  save_data.selected_pulse = static_cast<byte>(app.selected_pulse);
+  save_data.cv_run = app.cv_run;
+  save_data.cv_reset = app.cv_reset;
+
+  // TODO: break this out into a separate function. Save State should be
+  // broken out into global / per-channel save methods. When saving via
+  // "update" only save state for the current channel since other channels
+  // will not have changed when saving user edits.
+  for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
+    const auto &ch = app.channel[i];
+    auto &save_ch = save_data.channel_data[i];
+    save_ch.base_clock_mod_index = ch.getClockModIndex(false);
+    save_ch.base_euc_steps = ch.getSteps(false);
+    save_ch.base_euc_hits = ch.getHits(false);
+    save_ch.cv1_dest = static_cast<byte>(ch.getCv1Dest());
+    save_ch.cv2_dest = static_cast<byte>(ch.getCv2Dest());
+  }
+
+  int address = EEPROM_DATA_START_ADDR + (slot_index * sizeof(EepromData));
+  EEPROM.put(address, save_data);
+}
+
+void StateManager::_loadState(AppState &app, byte slot_index) {
+  // Check if slot_index is within max range + 1 for transient.
+  if (slot_index >= MAX_SAVE_SLOTS + 1)
+    return;
+
+  static EepromData load_data;
+  int address = EEPROM_DATA_START_ADDR + (slot_index * sizeof(EepromData));
+  EEPROM.get(address, load_data);
+
+  // Restore app state from loaded data.
+  app.tempo = load_data.tempo;
+  app.selected_param = load_data.selected_param;
+  app.selected_channel = load_data.selected_channel;
+  app.selected_source = static_cast<Clock::Source>(load_data.selected_source);
+  app.selected_pulse = static_cast<Clock::Pulse>(load_data.selected_pulse);
+  app.cv_run = load_data.cv_run;
+  app.cv_reset = load_data.cv_reset;
+
+  for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
+    auto &ch = app.channel[i];
+    const auto &saved_ch_state = load_data.channel_data[i];
+
+    ch.setClockMod(saved_ch_state.base_clock_mod_index);
+    ch.setSteps(saved_ch_state.base_euc_steps);
+    ch.setHits(saved_ch_state.base_euc_hits);
+    ch.setCv1Dest(static_cast<CvDestination>(saved_ch_state.cv1_dest));
+    ch.setCv2Dest(static_cast<CvDestination>(saved_ch_state.cv2_dest));
+  }
+}
+
+void StateManager::_saveMetadata(const AppState &app) {
+  Metadata current_meta;
+  strcpy(current_meta.sketch_name, SKETCH_NAME);
+  strcpy(current_meta.version, SEMANTIC_VERSION);
+
+  // Global user settings
+  current_meta.selected_save_slot = app.selected_save_slot;
+  current_meta.encoder_reversed = app.encoder_reversed;
+  current_meta.rotate_display = app.rotate_display;
+
+  EEPROM.put(METADATA_START_ADDR, current_meta);
+}
+
+void StateManager::_loadMetadata(AppState &app) {
+  Metadata metadata;
+  EEPROM.get(METADATA_START_ADDR, metadata);
+  app.selected_save_slot = metadata.selected_save_slot;
+  app.encoder_reversed = metadata.encoder_reversed;
+  app.rotate_display = metadata.rotate_display;
+}

firmware/Euclidean/save_state.h

@@ -0,0 +1,96 @@
+/**
+ * @file save_state.h
+ * @author Adam Wonak (https://github.com/awonak/)
+ * @brief Alt firmware version of Gravity by Sitka Instruments.
+ * @version 2.0.1
+ * @date 2025-07-04
+ *
+ * @copyright MIT - (c) 2025 - Adam Wonak - adam.wonak@gmail.com
+ *
+ */
+
+#ifndef SAVE_STATE_H
+#define SAVE_STATE_H
+
+#include <Arduino.h>
+#include <libGravity.h>
+
+// Forward-declare AppState to avoid circular dependencies.
+struct AppState;
+
+/**
+ * @brief Manages saving and loading of the application state to and from
+ * EEPROM. The number of user slots is defined by MAX_SAVE_SLOTS, and one
+ * additional slot is reseved for transient state to persist state between power
+ * cycles before state is explicitly saved to a user slot. Metadata is stored in
+ * the beginning of the memory space which stores firmware version information
+ * to validate that the data can be loaded into the current version of AppState.
+ */
+class StateManager {
+public:
+  static const char SKETCH_NAME[];
+  static const char SEMANTIC_VERSION[];
+  static const byte MAX_SAVE_SLOTS;
+  static const byte TRANSIENT_SLOT;
+
+  StateManager();
+
+  // Populate the AppState instance with values from EEPROM if they exist.
+  bool initialize(AppState &app);
+  // Load data from specified slot.
+  bool loadData(AppState &app, byte slot_index);
+  // Save data to specified slot.
+  void saveData(const AppState &app);
+  // Reset AppState instance back to default values.
+  void reset(AppState &app);
+  // Call from main loop, check if state has changed and needs to be saved.
+  void update(const AppState &app);
+  // Indicate that state has changed and we should save.
+  void markDirty();
+  // Erase all data stored in the EEPROM.
+  void factoryReset(AppState &app);
+
+  // This struct holds the data that identifies the firmware version.
+  struct Metadata {
+    char sketch_name[16];
+    char version[16];
+    // Additional global/hardware settings
+    byte selected_save_slot;
+    bool encoder_reversed;
+    bool rotate_display;
+  };
+  struct ChannelState {
+    byte base_clock_mod_index;
+    byte base_euc_steps;
+    byte base_euc_hits;
+    byte cv1_dest; // Cast the CvDestination enum as a byte for storage
+    byte cv2_dest; // Cast the CvDestination enum as a byte for storage
+  };
+  // This struct holds all the parameters we want to save.
+  struct EepromData {
+    int tempo;
+    byte selected_param;
+    byte selected_channel;
+    byte selected_source;
+    byte selected_pulse;
+    byte cv_run;
+    byte cv_reset;
+    ChannelState channel_data[Gravity::OUTPUT_COUNT];
+  };
+
+private:
+  bool _isDataValid();
+  void _saveMetadata(const AppState &app);
+  void _loadMetadata(AppState &app);
+  void _saveState(const AppState &app, byte slot_index);
+  void _loadState(AppState &app, byte slot_index);
+
+  static const unsigned long SAVE_DELAY_MS;
+  static const int METADATA_START_ADDR;
+  static const int EEPROM_DATA_START_ADDR;
+
+  bool _isDirty;
+  unsigned long _lastChangeTime;
+};
+
+#endif // SAVE_STATE_H

firmware/Gravity/Gravity.ino

@@ -2,11 +2,10 @@
  * @file Gravity.ino
  * @author Adam Wonak (https://github.com/awonak/)
  * @brief Alt firmware version of Gravity by Sitka Instruments.
- * @version v2.0.1 - June 2025 awonak - Full rewrite 
- * @version v1.0 - August 2023 Oleksiy H - Initial release
- * @date 2025-07-04
+ * @version v2.0.1beta1 - February 2026 awonak
+ * @date 2026-02-21
  *
- * @copyright MIT - (c) 2025 - Adam Wonak - adam.wonak@gmail.com
+ * @copyright MIT - (c) 2026 - Adam Wonak - adam.wonak@gmail.com
  *
  * This version of Gravity firmware is a full rewrite that leverages the
  * libGravity hardware abstraction library. The goal of this project was to
@@ -25,7 +24,7 @@
  * quantization of features like duty cycle (pulse width) or offset.
  * Additionally, this firmware replaces the sequencer with a Euclidean Rhythm
  * generator.
- * 
+ *
  * ENCODER:
  *      Press: change between selecting a parameter and editing the parameter.
  *      Hold & Rotate: change current selected output channel.
@@ -33,20 +32,25 @@
  * BTN1:
  *      Play/pause - start or stop the internal clock.
  *
- * BTN2: 
- *      Shift - hold and rotate encoder to change current selected output channel.
+ * BTN2:
+ *      Shift - hold and rotate encoder to change current selected output
+ * channel.
  *
  * EXT:
- *      External clock input. When Gravity is set to INTERNAL clock mode, this
- *      input is used to reset clocks.
- * 
+ *      External clock input. When Gravity is set to INTERNAL or MIDI clock
+ *      source, this input is used to reset clocks.
+ *
  * CV1:
+ *      External analog input used to provide modulation to any channel
+ * parameter.
+ *
  * CV2:
- *      External analog input used to provide modulation to any channel parameter.
- * 
+ *      External analog input used to provide modulation to any channel
+ * parameter.
+ *
  */
 
-#include <gravity.h>
+#include <libGravity.h>
 
 #include "app_state.h"
 #include "channel.h"
@@ -61,49 +65,75 @@ StateManager stateManager;
 //
 
 void setup() {
-    // Start Gravity.
-    gravity.Init();
+  // Start Gravity.
+  gravity.Init();
 
-    // Initialize the state manager. This will load settings from EEPROM
-    stateManager.initialize(app);
-    InitGravity(app);
+  // Show bootsplash when initializing firmware.
+  Bootsplash();
+  delay(2000);
 
-    // Clock handlers.
-    gravity.clock.AttachIntHandler(HandleIntClockTick);
-    gravity.clock.AttachExtHandler(HandleExtClockTick);
+  // Initialize the state manager. This will load settings from EEPROM
+  stateManager.initialize(app);
+  InitGravity(app);
 
-    // Encoder rotate and press handlers.
-    gravity.encoder.AttachPressHandler(HandleEncoderPressed);
-    gravity.encoder.AttachRotateHandler(HandleRotate);
-    gravity.encoder.AttachPressRotateHandler(HandlePressedRotate);
+  // Clock handlers.
+  gravity.clock.AttachIntHandler(HandleIntClockTick);
+  gravity.clock.AttachExtHandler(HandleExtClockTick);
 
-    // Button press handlers.
-    gravity.play_button.AttachPressHandler(HandlePlayPressed);
+  // Encoder rotate and press handlers.
+  gravity.encoder.AttachPressHandler(HandleEncoderPressed);
+  gravity.encoder.AttachRotateHandler(HandleRotate);
+  gravity.encoder.AttachPressRotateHandler(HandlePressedRotate);
+
+  // Button press handlers.
+  gravity.play_button.AttachPressHandler(HandlePlayPressed);
 }
 
 void loop() {
-    // Process change in state of inputs and outputs.
-    gravity.Process();
+  // Process change in state of inputs and outputs.
+  gravity.Process();
 
-    // Read CVs and call the update function for each channel.
-    int cv1 = gravity.cv1.Read();
-    int cv2 = gravity.cv2.Read();
+  // Read CVs and call the update function for each channel.
+  int cv1 = gravity.cv1.Read();
+  int cv2 = gravity.cv2.Read();
 
-    for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
-        auto& ch = app.channel[i];
-        // Only apply CV to the channel when the current channel has cv
-        // mod configured.
-        if (ch.isCvModActive()) {
-            ch.applyCvMod(cv1, cv2);
-        }
+  for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
+    auto &ch = app.channel[i];
+    // Only apply CV to the channel when the current channel has cv
+    // mod configured.
+    if (ch.isCvModActive()) {
+      ch.applyCvMod(cv1, cv2);
     }
+  }
 
-    // Check for dirty state eligible to be saved.
-    stateManager.update(app);
-
-    if (app.refresh_screen) {
-        UpdateDisplay();
+  // Clock Run
+  if (app.cv_run == 1 || app.cv_run == 2) {
+    auto &cv = app.cv_run == 1 ? gravity.cv1 : gravity.cv2;
+    int val = cv.Read();
+    if (val > AnalogInput::GATE_THRESHOLD && gravity.clock.IsPaused()) {
+      gravity.clock.Start();
+      app.refresh_screen = true;
+    } else if (val < AnalogInput::GATE_THRESHOLD && !gravity.clock.IsPaused()) {
+      gravity.clock.Stop();
+      ResetOutputs();
+      app.refresh_screen = true;
     }
+  }
+
+  // Clock Reset
+  if ((app.cv_reset == 1 &&
+       gravity.cv1.IsRisingEdge(AnalogInput::GATE_THRESHOLD)) ||
+      (app.cv_reset == 2 &&
+       gravity.cv2.IsRisingEdge(AnalogInput::GATE_THRESHOLD))) {
+    gravity.clock.Reset();
+  }
+
+  // Check for dirty state eligible to be saved.
+  stateManager.update(app);
+
+  if (app.refresh_screen) {
+    UpdateDisplay();
+  }
 }
 
 //
@@ -111,56 +141,59 @@ void loop() {
 //
 
 void HandleIntClockTick(uint32_t tick) {
-    bool refresh = false;
-    for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
-        app.channel[i].processClockTick(tick, gravity.outputs[i]);
+  bool refresh = false;
+  for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
+    app.channel[i].processClockTick(tick, gravity.outputs[i]);
 
-        if (app.channel[i].isCvModActive()) {
-            refresh = true;
-        }
+    if (app.channel[i].isCvModActive()) {
+      refresh = true;
+    }
+  }
+
+  // Pulse Out gate
+  if (app.selected_pulse != Clock::PULSE_NONE) {
+    int clock_index;
+    switch (app.selected_pulse) {
+    case Clock::PULSE_PPQN_24:
+      clock_index = PULSE_PPQN_24_CLOCK_MOD_INDEX;
+      break;
+    case Clock::PULSE_PPQN_4:
+      clock_index = PULSE_PPQN_4_CLOCK_MOD_INDEX;
+      break;
+    case Clock::PULSE_PPQN_1:
+      clock_index = PULSE_PPQN_1_CLOCK_MOD_INDEX;
+      break;
     }
 
-    // Pulse Out gate
-    if (app.selected_pulse != Clock::PULSE_NONE) {
-        int clock_index;
-        switch (app.selected_pulse) {
-            case Clock::PULSE_PPQN_24:
-                clock_index = PULSE_PPQN_24_CLOCK_MOD_INDEX;
-                break;
-            case Clock::PULSE_PPQN_4:
-                clock_index = PULSE_PPQN_4_CLOCK_MOD_INDEX;
-                break;
-            case Clock::PULSE_PPQN_1:
-                clock_index = PULSE_PPQN_1_CLOCK_MOD_INDEX;
-                break;
-        }
+    const uint16_t pulse_high_ticks =
+        pgm_read_word_near(&CLOCK_MOD_PULSES[clock_index]);
+    const uint32_t pulse_low_ticks = tick + max((pulse_high_ticks / 2), 1L);
 
-        const uint32_t pulse_high_ticks = CLOCK_MOD_PULSES[clock_index];
-        const uint32_t pulse_low_ticks = tick + max((pulse_high_ticks / 2), 1L);
-
-        if (tick % pulse_high_ticks == 0) {
-            gravity.pulse.High();
-        }
-        if (pulse_low_ticks % pulse_high_ticks == 0) {
-            gravity.pulse.Low();
-        }
+    if (tick % pulse_high_ticks == 0) {
+      gravity.pulse.High();
+    } else if (pulse_low_ticks % pulse_high_ticks == 0) {
+      gravity.pulse.Low();
     }
+  }
 
-    if (!app.editing_param) {
-        app.refresh_screen |= refresh;
-    }
+  if (!app.editing_param) {
+    app.refresh_screen |= refresh;
+  }
 }
 
 void HandleExtClockTick() {
-    if (gravity.clock.InternalSource()) {
-        // Use EXT as Reset when internally clocked.
-        ResetOutputs();
-        gravity.clock.Reset();
-    } else {
-        // Register clock tick.
-        gravity.clock.Tick();
-    }
-    app.refresh_screen = true;
+  switch (app.selected_source) {
+  case Clock::SOURCE_INTERNAL:
+  case Clock::SOURCE_EXTERNAL_MIDI:
+    // Use EXT as Reset when not used for clock source.
+    ResetOutputs();
+    gravity.clock.Reset();
+    break;
+  default:
+    // Register EXT cv clock tick.
+    gravity.clock.Tick();
+  }
+  app.refresh_screen = true;
 }
 
 //
@@ -168,178 +201,223 @@ void HandleExtClockTick() {
 //
 
 void HandlePlayPressed() {
-    gravity.clock.IsPaused()
-        ? gravity.clock.Start()
-        : gravity.clock.Stop();
-    ResetOutputs();
-    app.refresh_screen = true;
+  // Check if SHIFT is pressed to mute all/current channel.
+  if (gravity.shift_button.On()) {
+    if (app.selected_channel == 0) {
+      // Mute all channels
+      for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
+        app.channel[i].toggleMute();
+      }
+    } else {
+      // Mute selected channel
+      auto &ch = GetSelectedChannel();
+      ch.toggleMute();
+    }
+    return;
+  }
+
+  gravity.clock.IsPaused() ? gravity.clock.Start() : gravity.clock.Stop();
+  ResetOutputs();
+  app.refresh_screen = true;
 }
 
 void HandleEncoderPressed() {
-    // Check if leaving editing mode should apply a selection.
-    if (app.editing_param) {
-        if (app.selected_channel == 0) {  // main page
-            // TODO: rewrite as switch
-            if (app.selected_param == PARAM_MAIN_ENCODER_DIR) {
-                bool reversed = app.selected_sub_param == 1;
-                gravity.encoder.SetReverseDirection(reversed);
-            }
-            if (app.selected_param == PARAM_MAIN_SAVE_DATA) {
-                if (app.selected_sub_param < MAX_SAVE_SLOTS) {
-                    app.selected_save_slot = app.selected_sub_param;
-                    stateManager.saveData(app);
-                }
-            }
-            if (app.selected_param == PARAM_MAIN_LOAD_DATA) {
-                if (app.selected_sub_param < MAX_SAVE_SLOTS) {
-                    app.selected_save_slot = app.selected_sub_param;
-                    stateManager.loadData(app, app.selected_save_slot);
-                    InitGravity(app);
-                }
-            }
-            if (app.selected_param == PARAM_MAIN_RESET_STATE) {
-                if (app.selected_sub_param == 0) {  // Reset
-                    stateManager.reset(app);
-                    InitGravity(app);
-                }
-            }
+  // Check if leaving editing mode should apply a selection.
+  if (app.editing_param) {
+    if (app.selected_channel == 0) { // main page
+      // TODO: rewrite as switch
+      if (app.selected_param == PARAM_MAIN_ENCODER_DIR) {
+        app.encoder_reversed = app.selected_sub_param == 1;
+        gravity.encoder.SetReverseDirection(app.encoder_reversed);
+      }
+      if (app.selected_param == PARAM_MAIN_ROTATE_DISP) {
+        app.rotate_display = app.selected_sub_param == 1;
+        gravity.display.setFlipMode(app.rotate_display ? 1 : 0);
+      }
+      if (app.selected_param == PARAM_MAIN_SAVE_DATA) {
+        if (app.selected_sub_param < StateManager::MAX_SAVE_SLOTS) {
+          app.selected_save_slot = app.selected_sub_param;
+          stateManager.saveData(app);
         }
-        // Only mark dirty and reset selected_sub_param when leaving editing mode.
-        stateManager.markDirty();
-        app.selected_sub_param = 0;
+      }
+      if (app.selected_param == PARAM_MAIN_LOAD_DATA) {
+        if (app.selected_sub_param < StateManager::MAX_SAVE_SLOTS) {
+          app.selected_save_slot = app.selected_sub_param;
+          // Load pattern data into app state.
+          stateManager.loadData(app, app.selected_save_slot);
+          // Load global performance settings if they have changed.
+          if (gravity.clock.Tempo() != app.tempo) {
+            gravity.clock.SetTempo(app.tempo);
+          }
+          // Load global settings only if clock is not active.
+          if (gravity.clock.IsPaused()) {
+            InitGravity(app);
+          }
+        }
+      }
+      if (app.selected_param == PARAM_MAIN_RESET_STATE) {
+        if (app.selected_sub_param == 0) { // Reset
+          stateManager.reset(app);
+          InitGravity(app);
+        }
+      }
+      if (app.selected_param == PARAM_MAIN_FACTORY_RESET) {
+        if (app.selected_sub_param == 0) { // Erase
+          // Show bootsplash during slow erase operation.
+          Bootsplash();
+          stateManager.factoryReset(app);
+          InitGravity(app);
+        }
+      }
     }
+    // Only mark dirty and reset selected_sub_param when leaving editing mode.
+    stateManager.markDirty();
+    app.selected_sub_param = 0;
+  }
 
-    app.editing_param = !app.editing_param;
-    app.refresh_screen = true;
+  app.editing_param = !app.editing_param;
+  app.refresh_screen = true;
 }
 
 void HandleRotate(int val) {
-    // Shift & Rotate check
-    if (gravity.shift_button.On()) {
-        HandlePressedRotate(val);
-        return;
-    }
+  // Shift & Rotate check
+  if (gravity.shift_button.On()) {
+    HandlePressedRotate(val);
+    return;
+  }
 
-    if (!app.editing_param) {
-        // Navigation Mode
-        const int max_param = (app.selected_channel == 0) ? PARAM_MAIN_LAST : PARAM_CH_LAST;
-        updateSelection(app.selected_param, val, max_param);
+  if (!app.editing_param) {
+    // Navigation Mode
+    const int max_param =
+        (app.selected_channel == 0) ? PARAM_MAIN_LAST : PARAM_CH_LAST;
+    updateSelection(app.selected_param, val, max_param);
+  } else {
+    // Editing Mode
+    if (app.selected_channel == 0) {
+      editMainParameter(val);
     } else {
-        // Editing Mode
-        if (app.selected_channel == 0) {
-            editMainParameter(val);
-        } else {
-            editChannelParameter(val);
-        }
+      editChannelParameter(val);
     }
-    app.refresh_screen = true;
+  }
+  app.refresh_screen = true;
 }
 
 void HandlePressedRotate(int val) {
-    updateSelection(app.selected_channel, val, Gravity::OUTPUT_COUNT + 1);
-    app.selected_param = 0;
-    stateManager.markDirty();
-    app.refresh_screen = true;
+  updateSelection(app.selected_channel, val, Gravity::OUTPUT_COUNT + 1);
+  app.selected_param = 0;
+  stateManager.markDirty();
+  app.refresh_screen = true;
 }
 
 void editMainParameter(int val) {
-    switch (static_cast<ParamsMainPage>(app.selected_param)) {
-        case PARAM_MAIN_TEMPO:
-            if (gravity.clock.ExternalSource()) {
-                break;
-            }
-            gravity.clock.SetTempo(gravity.clock.Tempo() + val);
-            app.tempo = gravity.clock.Tempo();
-            break;
-        case PARAM_MAIN_SOURCE: {
-            byte source = static_cast<int>(app.selected_source);
-            updateSelection(source, val, Clock::SOURCE_LAST);
-            app.selected_source = static_cast<Clock::Source>(source);
-            gravity.clock.SetSource(app.selected_source);
-            break;
-        }
-        case PARAM_MAIN_PULSE: {
-            byte pulse = static_cast<int>(app.selected_pulse);
-            updateSelection(pulse, val, Clock::PULSE_LAST);
-            app.selected_pulse = static_cast<Clock::Pulse>(pulse);
-            if (app.selected_pulse == Clock::PULSE_NONE) {
-                gravity.pulse.Low();
-            }
-            break;
-        }
-        case PARAM_MAIN_ENCODER_DIR:
-            updateSelection(app.selected_sub_param, val, 2);
-            break;
-        case PARAM_MAIN_SAVE_DATA:
-        case PARAM_MAIN_LOAD_DATA:
-            updateSelection(app.selected_sub_param, val, MAX_SAVE_SLOTS + 1);
-            break;
-        case PARAM_MAIN_RESET_STATE:
-            updateSelection(app.selected_sub_param, val, 2);
-            break;
+  switch (static_cast<ParamsMainPage>(app.selected_param)) {
+  case PARAM_MAIN_TEMPO:
+    if (gravity.clock.ExternalSource()) {
+      break;
     }
+    gravity.clock.SetTempo(gravity.clock.Tempo() + val);
+    app.tempo = gravity.clock.Tempo();
+    break;
+  case PARAM_MAIN_RUN:
+    updateSelection(app.selected_sub_param, val, 3);
+    app.cv_run = app.selected_sub_param;
+    break;
+  case PARAM_MAIN_RESET:
+    updateSelection(app.selected_sub_param, val, 3);
+    app.cv_reset = app.selected_sub_param;
+    break;
+  case PARAM_MAIN_SOURCE: {
+    byte source = static_cast<int>(app.selected_source);
+    updateSelection(source, val, Clock::SOURCE_LAST);
+    app.selected_source = static_cast<Clock::Source>(source);
+    gravity.clock.SetSource(app.selected_source);
+    break;
+  }
+  case PARAM_MAIN_PULSE: {
+    byte pulse = static_cast<int>(app.selected_pulse);
+    updateSelection(pulse, val, Clock::PULSE_LAST);
+    app.selected_pulse = static_cast<Clock::Pulse>(pulse);
+    if (app.selected_pulse == Clock::PULSE_NONE) {
+      gravity.pulse.Low();
+    }
+    break;
+  }
+  // These changes are applied upon encoder button press.
+  case PARAM_MAIN_ENCODER_DIR:
+    updateSelection(app.selected_sub_param, val, 2);
+    break;
+  case PARAM_MAIN_ROTATE_DISP:
+    updateSelection(app.selected_sub_param, val, 2);
+    break;
+  case PARAM_MAIN_SAVE_DATA:
+  case PARAM_MAIN_LOAD_DATA:
+    updateSelection(app.selected_sub_param, val,
+                    StateManager::MAX_SAVE_SLOTS + 1);
+    break;
+  case PARAM_MAIN_RESET_STATE:
+    updateSelection(app.selected_sub_param, val, 2);
+    break;
+  case PARAM_MAIN_FACTORY_RESET:
+    updateSelection(app.selected_sub_param, val, 2);
+    break;
+  }
 }
 
 void editChannelParameter(int val) {
-    auto& ch = GetSelectedChannel();
-    switch (app.selected_param) {
-        case PARAM_CH_MOD:
-            ch.setClockMod(ch.getClockModIndex() + val);
-            break;
-        case PARAM_CH_PROB:
-            ch.setProbability(ch.getProbability() + val);
-            break;
-        case PARAM_CH_DUTY:
-            ch.setDutyCycle(ch.getDutyCycle() + val);
-            break;
-        case PARAM_CH_OFFSET:
-            ch.setOffset(ch.getOffset() + val);
-            break;
-        case PARAM_CH_SWING:
-            ch.setSwing(ch.getSwing() + val);
-            break;
-        case PARAM_CH_EUC_STEPS:
-            ch.setSteps(ch.getSteps() + val);
-            break;
-        case PARAM_CH_EUC_HITS:
-            ch.setHits(ch.getHits() + val);
-            break;
-        case PARAM_CH_CV1_DEST: {
-            byte dest = static_cast<int>(ch.getCv1Dest());
-            updateSelection(dest, val, CV_DEST_LAST);
-            ch.setCv1Dest(static_cast<CvDestination>(dest));
-            break;
-        }
-        case PARAM_CH_CV2_DEST: {
-            byte dest = static_cast<int>(ch.getCv2Dest());
-            updateSelection(dest, val, CV_DEST_LAST);
-            ch.setCv2Dest(static_cast<CvDestination>(dest));
-            break;
-        }
-    }
+  auto &ch = GetSelectedChannel();
+  switch (app.selected_param) {
+  case PARAM_CH_MOD:
+    ch.setClockMod(ch.getClockModIndex() + val);
+    break;
+  case PARAM_CH_PROB:
+    ch.setProbability(ch.getProbability() + val);
+    break;
+  case PARAM_CH_DUTY:
+    ch.setDutyCycle(ch.getDutyCycle() + val);
+    break;
+  case PARAM_CH_OFFSET:
+    ch.setOffset(ch.getOffset() + val);
+    break;
+  case PARAM_CH_SWING:
+    ch.setSwing(ch.getSwing() + val);
+    break;
+  case PARAM_CH_CV1_DEST: {
+    byte dest = static_cast<int>(ch.getCv1Dest());
+    updateSelection(dest, val, CV_DEST_LAST);
+    ch.setCv1Dest(static_cast<CvDestination>(dest));
+    break;
+  }
+  case PARAM_CH_CV2_DEST: {
+    byte dest = static_cast<int>(ch.getCv2Dest());
+    updateSelection(dest, val, CV_DEST_LAST);
+    ch.setCv2Dest(static_cast<CvDestination>(dest));
+    break;
+  }
+  }
 }
 
 // Changes the param by the value provided.
-void updateSelection(byte& param, int change, int maxValue) {
-    // Do not apply acceleration if max value is less than 25.
-    if (maxValue < 25) {
-        change = change > 0 ? 1 : -1;
-    }
-    param = constrain(param + change, 0, maxValue - 1);
+void updateSelection(byte &param, int change, int maxValue) {
+  // Do not apply acceleration if max value is less than 25.
+  if (maxValue < 25) {
+    change = change > 0 ? 1 : -1;
+  }
+  param = constrain(param + change, 0, maxValue - 1);
 }
 
 //
 // App Helper functions.
 //
 
-void InitGravity(AppState& app) {
-    gravity.clock.SetTempo(app.tempo);
-    gravity.clock.SetSource(app.selected_source);
-    gravity.encoder.SetReverseDirection(app.encoder_reversed);
+void InitGravity(AppState &app) {
+  gravity.clock.SetTempo(app.tempo);
+  gravity.clock.SetSource(app.selected_source);
+  gravity.encoder.SetReverseDirection(app.encoder_reversed);
+  gravity.display.setFlipMode(app.rotate_display ? 1 : 0);
 }
 
 void ResetOutputs() {
-    for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
-        gravity.outputs[i].Low();
-    }
+  for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
+    gravity.outputs[i].Low();
+  }
 }

firmware/Gravity/app_state.h

@@ -12,54 +12,33 @@
 #ifndef APP_STATE_H
 #define APP_STATE_H
 
-#include <gravity.h>
+#include <libGravity.h>
 
 #include "channel.h"
 
 // Global state for settings and app behavior.
 struct AppState {
-    int tempo = Clock::DEFAULT_TEMPO;
-    bool encoder_reversed = false;
-    bool refresh_screen = true;
-    bool editing_param = false;
-    byte selected_param = 0;
-    byte selected_sub_param = 0;  // Temporary value for editing params.
-    byte selected_channel = 0;    // 0=tempo, 1-6=output channel
-    byte selected_swing = 0;
-    byte selected_save_slot = 0;  // The currently active save slot.
-    Clock::Source selected_source = Clock::SOURCE_INTERNAL;
-    Clock::Pulse selected_pulse = Clock::PULSE_PPQN_24;
-    Channel channel[Gravity::OUTPUT_COUNT];
+  int tempo = Clock::DEFAULT_TEMPO;
+  Channel channel[Gravity::OUTPUT_COUNT];
+  byte selected_param = 0;
+  byte selected_sub_param = 0; // Temporary value for editing params.
+  byte selected_channel = 0;   // 0=tempo, 1-6=output channel
+  byte selected_swing = 0;
+  byte selected_save_slot = 0; // The currently active save slot.
+  byte cv_run = 0;
+  byte cv_reset = 0;
+  Clock::Source selected_source = Clock::SOURCE_INTERNAL;
+  Clock::Pulse selected_pulse = Clock::PULSE_PPQN_24;
+  bool editing_param = false;
+  bool encoder_reversed = false;
+  bool rotate_display = false;
+  bool refresh_screen = true;
 };
 
 extern AppState app;
 
-static Channel& GetSelectedChannel() {
-    return app.channel[app.selected_channel - 1];
+static Channel &GetSelectedChannel() {
+  return app.channel[app.selected_channel - 1];
 }
 
-enum ParamsMainPage : uint8_t {
-    PARAM_MAIN_TEMPO,
-    PARAM_MAIN_SOURCE,
-    PARAM_MAIN_PULSE,
-    PARAM_MAIN_ENCODER_DIR,
-    PARAM_MAIN_SAVE_DATA,
-    PARAM_MAIN_LOAD_DATA,
-    PARAM_MAIN_RESET_STATE,
-    PARAM_MAIN_LAST,
-};
-
-enum ParamsChannelPage : uint8_t {
-    PARAM_CH_MOD,
-    PARAM_CH_PROB,
-    PARAM_CH_DUTY,
-    PARAM_CH_OFFSET,
-    PARAM_CH_SWING,
-    PARAM_CH_EUC_STEPS,
-    PARAM_CH_EUC_HITS,
-    PARAM_CH_CV1_DEST,
-    PARAM_CH_CV2_DEST,
-    PARAM_CH_LAST,
-};
-
-#endif  // APP_STATE_H
+#endif // APP_STATE_H

firmware/Gravity/channel.h

@@ -13,295 +13,284 @@
 #define CHANNEL_H
 
 #include <Arduino.h>
-#include <gravity.h>
-
-#include "euclidean.h"
+#include <libGravity.h>
 
 // Enums for CV Mod destination
 enum CvDestination : uint8_t {
-    CV_DEST_NONE,
-    CV_DEST_MOD,
-    CV_DEST_PROB,
-    CV_DEST_DUTY,
-    CV_DEST_OFFSET,
-    CV_DEST_SWING,
-    CV_DEST_EUC_STEPS,
-    CV_DEST_EUC_HITS,
-    CV_DEST_LAST,
+  CV_DEST_NONE,
+  CV_DEST_MOD,
+  CV_DEST_PROB,
+  CV_DEST_DUTY,
+  CV_DEST_OFFSET,
+  CV_DEST_SWING,
+  CV_DEST_LAST,
 };
 
 static const byte MOD_CHOICE_SIZE = 25;
 
 // Negative numbers are multipliers, positive are divisors.
 static const int CLOCK_MOD[MOD_CHOICE_SIZE] PROGMEM = {
-    // Multipliers
-    -24, -16, -12, -8, -6, -4, -3, -2,
-    // Internal Clock Unity
-    1,
     // Divisors
-    2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 16, 24, 32, 64, 128};
+    128, 64, 32, 24, 16, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2,
+    // Internal Clock Unity (quarter note)
+    1,
+    // Multipliers
+    -2, -3, -4, -6, -8, -12, -16, -24};
 
 // This represents the number of clock pulses for a 96 PPQN clock source
 // that match the above div/mult mods.
 static const int CLOCK_MOD_PULSES[MOD_CHOICE_SIZE] PROGMEM = {
-    // Multiplier Pulses (96 / X)
-    4, 6, 8, 12, 16, 24, 32, 48,
+    // Divisor Pulses (96 * X)
+    12288, 6144, 3072, 2304, 1536, 1152, 1056, 960, 864, 768, 672, 576, 480,
+    384, 288, 192,
     // Internal Clock Pulses
     96,
-    // Divisor Pulses (96 * X)
-    192, 288, 384, 480, 576, 672, 768, 864, 960, 1056, 1152, 1536, 2304, 3072, 6144, 12288};
+    // Multiplier Pulses (96 / X)
+    48, 32, 24, 16, 12, 8, 6, 4};
 
-static const byte DEFAULT_CLOCK_MOD_INDEX = 8;  // x1 or 96 PPQN.
+static const byte DEFAULT_CLOCK_MOD_INDEX = 16; // x1 or 96 PPQN.
 
-static const byte PULSE_PPQN_24_CLOCK_MOD_INDEX = 0;
-static const byte PULSE_PPQN_4_CLOCK_MOD_INDEX = 4;
-static const byte PULSE_PPQN_1_CLOCK_MOD_INDEX = 8;
+static const byte PULSE_PPQN_24_CLOCK_MOD_INDEX = MOD_CHOICE_SIZE - 1;
+static const byte PULSE_PPQN_4_CLOCK_MOD_INDEX = MOD_CHOICE_SIZE - 6;
+static const byte PULSE_PPQN_1_CLOCK_MOD_INDEX = MOD_CHOICE_SIZE - 9;
 
 class Channel {
-   public:
-    Channel() {
-        Init();
+public:
+  Channel() { Init(); }
+
+  void Init() {
+    // Reset base values to their defaults
+    base_clock_mod_index = DEFAULT_CLOCK_MOD_INDEX;
+    base_probability = 100;
+    base_duty_cycle = 50;
+    base_offset = 0;
+    base_swing = 50;
+
+    cvmod_clock_mod_index = base_clock_mod_index;
+    cvmod_probability = base_probability;
+    cvmod_duty_cycle = base_duty_cycle;
+    cvmod_offset = base_offset;
+    cvmod_swing = base_swing;
+
+    cv1_dest = CV_DEST_NONE;
+    cv2_dest = CV_DEST_NONE;
+
+    // Calcule the clock mod pulses on init.
+    _recalculatePulses();
+  }
+
+  // Setters (Set the BASE value)
+
+  void setClockMod(int index) {
+    base_clock_mod_index = constrain(index, 0, MOD_CHOICE_SIZE - 1);
+    if (!isCvModActive()) {
+      cvmod_clock_mod_index = base_clock_mod_index;
+      _recalculatePulses();
+    }
+  }
+
+  void setProbability(int prob) {
+    base_probability = constrain(prob, 0, 100);
+    if (!isCvModActive()) {
+      cvmod_probability = base_probability;
+      _recalculatePulses();
+    }
+  }
+
+  void setDutyCycle(int duty) {
+    base_duty_cycle = constrain(duty, 1, 99);
+    if (!isCvModActive()) {
+      cvmod_duty_cycle = base_duty_cycle;
+      _recalculatePulses();
+    }
+  }
+
+  void setOffset(int off) {
+    base_offset = constrain(off, 0, 99);
+    if (!isCvModActive()) {
+      cvmod_offset = base_offset;
+      _recalculatePulses();
+    }
+  }
+  void setSwing(int val) {
+    base_swing = constrain(val, 50, 95);
+    if (!isCvModActive()) {
+      cvmod_swing = base_swing;
+      _recalculatePulses();
+    }
+  }
+
+  void setCv1Dest(CvDestination dest) { cv1_dest = dest; }
+  void setCv2Dest(CvDestination dest) { cv2_dest = dest; }
+  CvDestination getCv1Dest() const { return cv1_dest; }
+  CvDestination getCv2Dest() const { return cv2_dest; }
+
+  // Getters (Get the BASE value for editing or cv modded value for display)
+
+  int getProbability(bool withCvMod = false) const {
+    return withCvMod ? cvmod_probability : base_probability;
+  }
+  int getDutyCycle(bool withCvMod = false) const {
+    return withCvMod ? cvmod_duty_cycle : base_duty_cycle;
+  }
+  int getOffset(bool withCvMod = false) const {
+    return withCvMod ? cvmod_offset : base_offset;
+  }
+  int getSwing(bool withCvMod = false) const {
+    return withCvMod ? cvmod_swing : base_swing;
+  }
+  int getClockMod(bool withCvMod = false) const {
+    return pgm_read_word_near(&CLOCK_MOD[getClockModIndex(withCvMod)]);
+  }
+  int getClockModIndex(bool withCvMod = false) const {
+    return withCvMod ? cvmod_clock_mod_index : base_clock_mod_index;
+  }
+  bool isCvModActive() const {
+    return cv1_dest != CV_DEST_NONE || cv2_dest != CV_DEST_NONE;
+  }
+
+  void toggleMute() { mute = !mute; }
+
+  /**
+   * @brief Processes a clock tick and determines if the output should be high
+   * or low. Note: this method is called from an ISR and must be kept as simple
+   * as possible.
+   * @param tick The current clock tick count.
+   * @param output The output object to be modified.
+   */
+  void processClockTick(uint32_t tick, DigitalOutput &output) {
+    // Mute check
+    if (mute) {
+      output.Low();
+      return;
     }
 
-    void Init() {
-        // Reset base values to their defaults
-        base_clock_mod_index = DEFAULT_CLOCK_MOD_INDEX;
-        base_probability = 100;
-        base_duty_cycle = 50;
-        base_offset = 0;
-        base_swing = 50;
-        base_euc_steps = 1;
-        base_euc_hits = 1;
+    const uint16_t mod_pulses =
+        pgm_read_word_near(&CLOCK_MOD_PULSES[cvmod_clock_mod_index]);
 
-        cvmod_clock_mod_index = base_clock_mod_index;
-        cvmod_probability = base_probability;
-        cvmod_duty_cycle = base_duty_cycle;
-        cvmod_offset = base_offset;
-        cvmod_swing = base_swing;
-
-        cv1_dest = CV_DEST_NONE;
-        cv2_dest = CV_DEST_NONE;
-
-        pattern.Init(DEFAULT_PATTERN);
-
-        // Calcule the clock mod pulses on init.
-        _recalculatePulses();
+    // Conditionally apply swing on down beats.
+    uint16_t swing_pulses = 0;
+    if (_swing_pulse_amount > 0 && (tick / mod_pulses) % 2 == 1) {
+      swing_pulses = _swing_pulse_amount;
     }
 
-    // Setters (Set the BASE value)
-
-    void setClockMod(int index) {
-        base_clock_mod_index = constrain(index, 0, MOD_CHOICE_SIZE - 1);
-        if (!isCvModActive()) {
-            cvmod_clock_mod_index = base_clock_mod_index;
-            _recalculatePulses();
+    // Duty cycle high check logic
+    const uint32_t current_tick_offset = tick + _offset_pulses + swing_pulses;
+    if (!output.On()) {
+      // Step check
+      if (current_tick_offset % mod_pulses == 0) {
+        bool hit = cvmod_probability >= random(0, 100);
+        if (hit) {
+          output.High();
         }
+      }
     }
 
-    void setProbability(int prob) {
-        base_probability = constrain(prob, 0, 100);
-        if (!isCvModActive()) {
-            cvmod_probability = base_probability;
-            _recalculatePulses();
-        }
+    // Duty cycle low check
+    const uint32_t duty_cycle_end_tick =
+        tick + _duty_pulses + _offset_pulses + swing_pulses;
+    if (duty_cycle_end_tick % mod_pulses == 0) {
+      output.Low();
+    }
+  }
+  /**
+   * @brief Calculate and store cv modded values using bipolar mapping.
+   * Default to base value if not the current CV destination.
+   *
+   * @param cv1_val analog input reading for cv1
+   * @param cv2_val analog input reading for cv2
+   *
+   */
+  void applyCvMod(int cv1_val, int cv2_val) {
+    // Note: This is optimized for cpu performance. This method is called
+    // from the main loop and stores the cv mod values. This reduces CPU
+    // cycles inside the internal clock interrupt, which is preferrable.
+    // However, if RAM usage grows too much, we have an opportunity to
+    // refactor this to store just the CV read values, and calculate the
+    // cv mod value per channel inside the getter methods by passing cv
+    // values. This would reduce RAM usage, but would introduce a
+    // significant CPU cost, which may have undesirable performance issues.
+    if (!isCvModActive()) {
+      cvmod_clock_mod_index = base_clock_mod_index;
+      cvmod_probability = base_clock_mod_index;
+      cvmod_duty_cycle = base_clock_mod_index;
+      cvmod_offset = base_clock_mod_index;
+      cvmod_swing = base_clock_mod_index;
+      return;
     }
 
-    void setDutyCycle(int duty) {
-        base_duty_cycle = constrain(duty, 1, 99);
-        if (!isCvModActive()) {
-            cvmod_duty_cycle = base_duty_cycle;
-            _recalculatePulses();
-        }
+    int dest_mod = _calculateMod(CV_DEST_MOD, cv1_val, cv2_val,
+                                 -(MOD_CHOICE_SIZE / 2), MOD_CHOICE_SIZE / 2);
+    cvmod_clock_mod_index = constrain(base_clock_mod_index + dest_mod, 0, 100);
+
+    int prob_mod = _calculateMod(CV_DEST_PROB, cv1_val, cv2_val, -50, 50);
+    cvmod_probability = constrain(base_probability + prob_mod, 0, 100);
+
+    int duty_mod = _calculateMod(CV_DEST_DUTY, cv1_val, cv2_val, -50, 50);
+    cvmod_duty_cycle = constrain(base_duty_cycle + duty_mod, 1, 99);
+
+    int offset_mod = _calculateMod(CV_DEST_OFFSET, cv1_val, cv2_val, -50, 50);
+    cvmod_offset = constrain(base_offset + offset_mod, 0, 99);
+
+    int swing_mod = _calculateMod(CV_DEST_SWING, cv1_val, cv2_val, -25, 25);
+    cvmod_swing = constrain(base_swing + swing_mod, 50, 95);
+
+    // After all cvmod values are updated, recalculate clock pulse modifiers.
+    _recalculatePulses();
+  }
+
+private:
+  int _calculateMod(CvDestination dest, int cv1_val, int cv2_val, int min_range,
+                    int max_range) {
+    int mod1 =
+        (cv1_dest == dest) ? map(cv1_val, -512, 512, min_range, max_range) : 0;
+    int mod2 =
+        (cv2_dest == dest) ? map(cv2_val, -512, 512, min_range, max_range) : 0;
+    return mod1 + mod2;
+  }
+
+  void _recalculatePulses() {
+    const uint16_t mod_pulses =
+        pgm_read_word_near(&CLOCK_MOD_PULSES[cvmod_clock_mod_index]);
+    _duty_pulses =
+        max((long)((mod_pulses * (100L - cvmod_duty_cycle)) / 100L), 1L);
+    _offset_pulses = (long)((mod_pulses * (100L - cvmod_offset)) / 100L);
+
+    // Calculate the down beat swing amount.
+    if (cvmod_swing > 50) {
+      int shifted_swing = cvmod_swing - 50;
+      _swing_pulse_amount =
+          (long)((mod_pulses * (100L - shifted_swing)) / 100L);
+    } else {
+      _swing_pulse_amount = 0;
     }
+  }
 
-    void setOffset(int off) {
-        base_offset = constrain(off, 0, 99);
-        if (!isCvModActive()) {
-            cvmod_offset = base_offset;
-            _recalculatePulses();
-        }
-    }
-    void setSwing(int val) {
-        base_swing = constrain(val, 50, 95);
-        if (!isCvModActive()) {
-            cvmod_swing = base_swing;
-            _recalculatePulses();
-        }
-    }
+  // User-settable base values.
+  byte base_clock_mod_index;
+  byte base_probability;
+  byte base_duty_cycle;
+  byte base_offset;
+  byte base_swing;
 
-    // Euclidean
-    void setSteps(int val) {
-        base_euc_steps = constrain(val, 1, MAX_PATTERN_LEN);
-        if (cv1_dest != CV_DEST_EUC_STEPS && cv2_dest != CV_DEST_EUC_STEPS) {
-            pattern.SetSteps(val);
-        }
-    }
-    void setHits(int val) {
-        base_euc_hits = constrain(val, 1, base_euc_steps);
-        if (cv1_dest != CV_DEST_EUC_HITS && cv2_dest != CV_DEST_EUC_HITS) {
-            pattern.SetHits(val);
-        }
-    }
+  // Base value with cv mod applied.
+  byte cvmod_clock_mod_index;
+  byte cvmod_probability;
+  byte cvmod_duty_cycle;
+  byte cvmod_offset;
+  byte cvmod_swing;
 
-    void setCv1Dest(CvDestination dest) { cv1_dest = dest; }
-    void setCv2Dest(CvDestination dest) { cv2_dest = dest; }
-    CvDestination getCv1Dest() const { return cv1_dest; }
-    CvDestination getCv2Dest() const { return cv2_dest; }
+  // CV mod configuration
+  CvDestination cv1_dest;
+  CvDestination cv2_dest;
 
-    // Getters (Get the BASE value for editing or cv modded value for display)
+  // Mute channel flag
+  bool mute;
 
-    int getProbability(bool withCvMod = false) const { return withCvMod ? cvmod_probability : base_probability; }
-    int getDutyCycle(bool withCvMod = false) const { return withCvMod ? cvmod_duty_cycle : base_duty_cycle; }
-    int getOffset(bool withCvMod = false) const { return withCvMod ? cvmod_offset : base_offset; }
-    int getSwing(bool withCvMod = false) const { return withCvMod ? cvmod_swing : base_swing; }
-    int getClockMod(bool withCvMod = false) const { return pgm_read_word_near(&CLOCK_MOD[getClockModIndex(withCvMod)]); }
-    int getClockModIndex(bool withCvMod = false) const { return withCvMod ? cvmod_clock_mod_index : base_clock_mod_index; }
-    bool isCvModActive() const { return cv1_dest != CV_DEST_NONE || cv2_dest != CV_DEST_NONE; }
-
-    byte getSteps(bool withCvMod = false) const { return withCvMod ? pattern.GetSteps() : base_euc_steps; }
-    byte getHits(bool withCvMod = false) const { return withCvMod ? pattern.GetHits() : base_euc_hits; }
-
-    /**
-     * @brief Processes a clock tick and determines if the output should be high or low.
-     * Note: this method is called from an ISR and must be kept as simple as possible.
-     * @param tick The current clock tick count.
-     * @param output The output object to be modified.
-     */
-    void processClockTick(uint32_t tick, DigitalOutput& output) {
-        const uint16_t mod_pulses = pgm_read_word_near(&CLOCK_MOD_PULSES[cvmod_clock_mod_index]);
-
-        // Conditionally apply swing on down beats.
-        uint16_t swing_pulses = 0;
-        if (_swing_pulse_amount > 0 && (tick / mod_pulses) % 2 == 1) {
-            swing_pulses = _swing_pulse_amount;
-        }
-
-        // Duty cycle high check logic
-        const uint32_t current_tick_offset = tick + _offset_pulses + swing_pulses;
-        if (!output.On()) {
-            // Step check
-            if (current_tick_offset % mod_pulses == 0) {
-                bool hit = cvmod_probability >= random(0, 100);
-                // Euclidean rhythm hit check
-                switch (pattern.NextStep()) {
-                    case Pattern::REST:  // Rest when active or fall back to probability
-                        hit = false;
-                        break;
-                    case Pattern::HIT:  // Hit if probability is true
-                        hit &= true;
-                        break;
-                }
-                if (hit) {
-                    output.High();
-                }
-            }
-        }
-
-        // Duty cycle low check
-        const uint32_t duty_cycle_end_tick = tick + _duty_pulses + _offset_pulses + swing_pulses;
-        if (duty_cycle_end_tick % mod_pulses == 0) {
-            output.Low();
-        }
-    }
-    /**
-     * @brief Calculate and store cv modded values using bipolar mapping.
-     * Default to base value if not the current CV destination.
-     *
-     * @param cv1_val analog input reading for cv1
-     * @param cv2_val analog input reading for cv2
-     *
-     */
-    void applyCvMod(int cv1_val, int cv2_val) {
-        // Note: This is optimized for cpu performance. This method is called
-        // from the main loop and stores the cv mod values. This reduces CPU
-        // cycles inside the internal clock interrupt, which is preferrable.
-        // However, if RAM usage grows too much, we have an opportunity to
-        // refactor this to store just the CV read values, and calculate the
-        // cv mod value per channel inside the getter methods by passing cv
-        // values. This would reduce RAM usage, but would introduce a
-        // significant CPU cost, which may have undesirable performance issues.
-        if (!isCvModActive()) {
-            cvmod_clock_mod_index = base_clock_mod_index;
-            cvmod_probability = base_clock_mod_index;
-            cvmod_duty_cycle = base_clock_mod_index;
-            cvmod_offset = base_clock_mod_index;
-            cvmod_swing = base_clock_mod_index;
-            return;
-        }
-
-        int dest_mod = _calculateMod(CV_DEST_MOD, cv1_val, cv2_val, -(MOD_CHOICE_SIZE / 2), MOD_CHOICE_SIZE / 2);
-        cvmod_clock_mod_index = constrain(base_clock_mod_index + dest_mod, 0, 100);
-
-        int prob_mod = _calculateMod(CV_DEST_PROB, cv1_val, cv2_val, -50, 50);
-        cvmod_probability = constrain(base_probability + prob_mod, 0, 100);
-
-        int duty_mod = _calculateMod(CV_DEST_DUTY, cv1_val, cv2_val, -50, 50);
-        cvmod_duty_cycle = constrain(base_duty_cycle + duty_mod, 1, 99);
-
-        int offset_mod = _calculateMod(CV_DEST_OFFSET, cv1_val, cv2_val, -50, 50);
-        cvmod_offset = constrain(base_offset + offset_mod, 0, 99);
-
-        int swing_mod = _calculateMod(CV_DEST_SWING, cv1_val, cv2_val, -25, 25);
-        cvmod_swing = constrain(base_swing + swing_mod, 50, 95);
-
-        int step_mod = _calculateMod(CV_DEST_EUC_STEPS, cv1_val, cv2_val, 0, MAX_PATTERN_LEN);
-        pattern.SetSteps(base_euc_steps + step_mod);
-
-        int hit_mod = _calculateMod(CV_DEST_EUC_HITS, cv1_val, cv2_val, 0, MAX_PATTERN_LEN);
-        pattern.SetHits(base_euc_hits + hit_mod);
-
-        // After all cvmod values are updated, recalculate clock pulse modifiers.
-        _recalculatePulses();
-    }
-
-   private:
-    int _calculateMod(CvDestination dest, int cv1_val, int cv2_val, int min_range, int max_range) {
-        int mod1 = (cv1_dest == dest) ? map(cv1_val, -512, 512, min_range, max_range) : 0;
-        int mod2 = (cv2_dest == dest) ? map(cv2_val, -512, 512, min_range, max_range) : 0;
-        return mod1 + mod2;
-    }
-
-    void _recalculatePulses() {
-        const uint16_t mod_pulses = pgm_read_word_near(&CLOCK_MOD_PULSES[cvmod_clock_mod_index]);
-        _duty_pulses = max((long)((mod_pulses * (100L - cvmod_duty_cycle)) / 100L), 1L);
-        _offset_pulses = (long)((mod_pulses * (100L - cvmod_offset)) / 100L);
-
-        // Calculate the down beat swing amount.
-        if (cvmod_swing > 50) {
-            int shifted_swing = cvmod_swing - 50;
-            _swing_pulse_amount = (long)((mod_pulses * (100L - shifted_swing)) / 100L);
-        } else {
-            _swing_pulse_amount = 0;
-        }
-    }
-
-    // User-settable base values.
-    byte base_clock_mod_index;
-    byte base_probability;
-    byte base_duty_cycle;
-    byte base_offset;
-    byte base_swing;
-    byte base_euc_steps;
-    byte base_euc_hits;
-
-    // Base value with cv mod applied.
-    byte cvmod_clock_mod_index;
-    byte cvmod_probability;
-    byte cvmod_duty_cycle;
-    byte cvmod_offset;
-    byte cvmod_swing;
-
-    // CV mod configuration
-    CvDestination cv1_dest;
-    CvDestination cv2_dest;
-
-    // Euclidean pattern
-    Pattern pattern;
-
-    // Pre-calculated pulse values for ISR performance
-    uint16_t _duty_pulses;
-    uint16_t _offset_pulses;
-    uint16_t _swing_pulse_amount;
+  // Pre-calculated pulse values for ISR performance
+  uint16_t _duty_pulses;
+  uint16_t _offset_pulses;
+  uint16_t _swing_pulse_amount;
 };
 
-#endif  // CHANNEL_H
+#endif // CHANNEL_H

firmware/Gravity/display.h

@@ -29,17 +29,24 @@
 const uint8_t TEXT_FONT[437] U8G2_FONT_SECTION("velvetscreen") PROGMEM =
     "\64\0\2\2\3\3\2\3\4\5\5\0\0\5\0\5\0\0\221\0\0\1\230 \4\200\134%\11\255tT"
     "R\271RI(\6\252\334T\31)\7\252\134bJ\12+\7\233\345\322J\0,\5\221T\4-\5\213"
-    "f\6.\5\211T\2/\6\244\354c\33\60\10\254\354T\64\223\2\61\7\353\354\222\254\6\62\11\254l"
-    "\66J*\217\0\63\11\254l\66J\32\215\4\64\10\254l\242\34\272\0\65\11\254l\206\336h$\0\66"
-    "\11\254\354T^\61)\0\67\10\254lF\216u\4\70\11\254\354TL*&\5\71\11\254\354TL;"
+    "f\6.\5\211T\2/"
+    "\6\244\354c\33\60\10\254\354T\64\223\2\61\7\353\354\222\254\6\62\11\254l"
+    "\66J*"
+    "\217\0\63\11\254l\66J\32\215\4\64\10\254l\242\34\272\0\65\11\254l\206\336h"
+    "$\0\66"
+    "\11\254\354T^\61)\0\67\10\254lF\216u\4\70\11\254\354TL*&"
+    "\5\71\11\254\354TL;"
     ")\0:\6\231UR\0A\10\254\354T\34S\6B\11\254lV\34)\216\4C\11\254\354T\324\61"
     ")\0D\10\254lV\64G\2E\10\254l\206\36z\4F\10\254l\206^\71\3G\11\254\354TN"
-    "\63)\0H\10\254l\242\34S\6I\6\251T\206\0J\10\254\354k\231\24\0K\11\254l\242J\62"
+    "\63)"
+    "\0H\10\254l\242\34S\6I\6\251T\206\0J\10\254\354k\231\24\0K\11\254l\242J\62"
     "\225\1L\7\254lr{\4M\11\255t\362ZI\353\0N\11\255t\362TI\356\0O\10\254\354T"
-    "\64\223\2P\11\254lV\34)g\0Q\10\254\354T\264b\12R\10\254lV\34\251\31S\11\254\354"
+    "\64\223\2P\11\254lV\34)"
+    "g\0Q\10\254\354T\264b\12R\10\254lV\34\251\31S\11\254\354"
     "FF\32\215\4T\7\253dVl\1U\10\254l\242\63)\0V\11\255t\262Ne\312\21W\12\255"
     "t\262J*\251.\0X\11\254l\242L*\312\0Y\12\255tr\252\63\312(\2Z\7\253df*"
-    "\7p\10\255\364V\266\323\2q\7\255\364\216\257\5r\10\253d\242\32*\2t\6\255t\376#w\11"
+    "\7p\10\255\364V\266\323\2q\7\255\364\216\257\5r\10\253d\242\32*"
+    "\2t\6\255t\376#w\11"
     "\255\364V\245FN\13x\6\233dR\7\0\0\0\4\377\377\0";
 
 /*
@@ -49,40 +56,61 @@ const uint8_t TEXT_FONT[437] U8G2_FONT_SECTION("velvetscreen") PROGMEM =
  */
 const uint8_t LARGE_FONT[766] U8G2_FONT_SECTION("stk-l") =
     "\35\0\4\4\4\5\3\1\6\20\30\0\0\27\0\0\0\1\77\0\0\2\341%'\17;\226\261\245FL"
-    "\64B\214\30\22\223\220)Bj\10Q\232\214\42R\206\310\210\21d\304\30\32a\254\304\270!\0/\14"
-    "\272\272\275\311H\321g\343\306\1\60\37|\373\35CJT\20:fW\207\320\210\60\42\304\204\30D\247"
-    "\214\331\354\20\11%\212\314\0\61\24z\275\245a\244\12\231\71\63b\214\220q\363\377(E\6\62\33|"
-    "\373\35ShT\20:fl\344\14\211\231\301\306T\71\202#g\371\340\201\1\63\34|\373\35ShT"
-    "\20:fl\344@r\264\263\222\344,\215\35\42\241\6\225\31\0\64 |\373-!\203\206\214!\62\204"
-    "\314\220A#\10\215\30\65b\324\210Q\306\354\354\1\213\225\363\1\65\32|\373\15\25[\214\234/\10)"
+    "\64B\214\30\22\223\220)"
+    "Bj\10Q\232\214\42R\206\310\210\21d\304\30\32a\254\304\270!\0/\14"
+    "\272\272\275\311H\321g\343\306\1\60\37|\373\35CJT\20:"
+    "fW\207\320\210\60\42\304\204\30D\247"
+    "\214\331\354\20\11%"
+    "\212\314\0\61\24z\275\245a\244\12\231\71\63b\214\220q\363\377(E\6\62\33|"
+    "\373\35ShT\20:fl\344\14\211\231\301\306T\71\202#g\371\340\201\1\63\34|"
+    "\373\35ShT"
+    "\20:fl\344@r\264\263\222\344,\215\35\42\241\6\225\31\0\64 "
+    "|\373-!\203\206\214!\62\204"
+    "\314\220A#\10\215\30\65b\324\210Q\306\354\354\1\213\225\363\1\65\32|"
+    "\373\15\25[\214\234/\10)"
     "Y\61j\350\310Y\32;DB\15*\63\0\66\33}\33\236SiV\14;gt^\230Y\302\202\324"
-    "\71\273;EbM\252\63\0\67\23|\373\205\25\17R\316\207\344\350p\312\201#\347\35\0\70 |\373"
-    "\35ShT\20:f\331!\22D\310 :\205\206\10\11B\307\354\354\20\11\65\250\314\0\71\32|\373"
+    "\71\273;EbM\252\63\0\67\23|\373\205\25\17R\316\207\344\350p\312\201#"
+    "\347\35\0\70 |\373"
+    "\35ShT\20:f\331!\22D\310 "
+    ":\205\206\10\11B\307\354\354\20\11\65\250\314\0\71\32|\373"
     "\35ShT\20:fg\207H,Q\223r\276\30DB\15*\63\0A\26}\33\246r\247\322P\62"
-    "j\310\250\21\343\354\335\203\357\354w\3B$}\33\206Dj\226\214\42\61l\304\260\21\303F\14\33\61"
-    "\212\304\222MF\221\30v\316\236=\10\301b\11\0C\27}\33\236Si\226\20Bft\376O\211\215"
-    " Db\215\42$\0D\33}\33\206Dj\226\214\32\62l\304\260\21\343\354\177vl\304(\22K\324"
-    "$\2E\22|\373\205\17R\316KD\30\215\234_>x`\0F\20|\373\205\17R\316\227i\262\31"
-    "\71\377\22\0I\7s\333\204\77HL\15{\333\205\201\363\377\77|\360`\0N$}\33\6\201\346\314"
-    "\35;\206\12U\242D&\306\230\30cd\210\221!fF\230\31a(+\314\256\63\67\0O\26}\33"
-    "\236Si\226\214\32\61\316\376\277\33\61j\310\232Tg\0R\61\216;\6Ek\230\14#\61n\304\270"
-    "\21\343F\214\33\61n\304\60\22\243\210\60Q\224j\310\260\61\243\306\20\232\325\230QD\206\221\30\67b"
-    "\334\301\1S\42\216;\236c\211\226\220\42\61n\304\270\21c\307R\232,[\262\203\307\216\65h\16\25"
-    "\21&\253\320\0T\15}\33\206\17R\15\235\377\377\25\0U\21|\373\205a\366\377\237\215\30\64D\15"
-    "*\63\0V\26\177\371\205\221\366\377\313\21\343\206\220\42C\25\11r'\313\16\3X)~;\206\201\6"
-    "\217\221\30\66\204\20\31\42\244\206\14Cg\320$Q\222\6\315!\33\62\212\10\31BD\206\215 v\320"
-    "\302\1x\24\312\272\205A\206\216\220@c\212\224\31$S\14\262h\0\0\0\0\4\377\377\0";
+    "j\310\250\21\343\354\335\203\357\354w\3B$}"
+    "\33\206Dj\226\214\42\61l\304\260\21\303F\14\33\61"
+    "\212\304\222MF\221\30v\316\236=\10\301b\11\0C\27}"
+    "\33\236Si\226\20Bft\376O\211\215"
+    " Db\215\42$\0D\33}\33\206Dj\226\214\32\62l\304\260\21\343\354\177vl\304("
+    "\22K\324"
+    "$\2E\22|\373\205\17R\316KD\30\215\234_>x`\0F\20|"
+    "\373\205\17R\316\227i\262\31"
+    "\71\377\22\0I\7s\333\204\77HL\15{\333\205\201\363\377\77|\360`\0N$}"
+    "\33\6\201\346\314"
+    "\35;\206\12U\242D&\306\230\30cd\210\221!fF\230\31a(+\314\256\63\67\0O\26}"
+    "\33"
+    "\236Si\226\214\32\61\316\376\277\33\61j\310\232Tg\0R\61\216;\6Ek\230\14#"
+    "\61n\304\270"
+    "\21\343F\214\33\61n\304\60\22\243\210\60Q\224j\310\260\61\243\306\20\232"
+    "\325\230QD\206\221\30\67b"
+    "\334\301\1S\42\216;\236c\211\226\220\42\61n\304\270\21c\307R\232,["
+    "\262\203\307\216\65h\16\25"
+    "\21&\253\320\0T\15}\33\206\17R\15\235\377\377\25\0U\21|"
+    "\373\205a\366\377\237\215\30\64D\15"
+    "*\63\0V\26\177\371\205\221\366\377\313\21\343\206\220\42C\25\11r'"
+    "\313\16\3X)~;\206\201\6"
+    "\217\221\30\66\204\20\31\42\244\206\14Cg\320$Q\222\6\315!"
+    "\33\62\212\10\31BD\206\215 v\320"
+    "\302\1x\24\312\272\205A\206\216\220@c\212\224\31$"
+    "S\14\262h\0\0\0\0\4\377\377\0";
 
 #define play_icon_width 14
 #define play_icon_height 14
 static const unsigned char play_icon[28] PROGMEM = {
-    0x00, 0x00, 0x00, 0x00, 0x3C, 0x00, 0x7C, 0x00, 0xFC, 0x00, 0xFC, 0x03,
-    0xFC, 0x0F, 0xFC, 0x0F, 0xFC, 0x03, 0xFC, 0x00, 0x7C, 0x00, 0x3C, 0x00,
-    0x00, 0x00, 0x00, 0x00};
+    0x00, 0x00, 0x00, 0x00, 0x3C, 0x00, 0x7C, 0x00, 0xFC, 0x00,
+    0xFC, 0x03, 0xFC, 0x0F, 0xFC, 0x0F, 0xFC, 0x03, 0xFC, 0x00,
+    0x7C, 0x00, 0x3C, 0x00, 0x00, 0x00, 0x00, 0x00};
 static const unsigned char pause_icon[28] PROGMEM = {
-    0x00, 0x00, 0x00, 0x00, 0x38, 0x0E, 0x38, 0x0E, 0x38, 0x0E, 0x38, 0x0E,
-    0x38, 0x0E, 0x38, 0x0E, 0x38, 0x0E, 0x38, 0x0E, 0x38, 0x0E, 0x38, 0x0E,
-    0x38, 0x0E, 0x00, 0x00};
+    0x00, 0x00, 0x00, 0x00, 0x38, 0x0E, 0x38, 0x0E, 0x38, 0x0E,
+    0x38, 0x0E, 0x38, 0x0E, 0x38, 0x0E, 0x38, 0x0E, 0x38, 0x0E,
+    0x38, 0x0E, 0x38, 0x0E, 0x38, 0x0E, 0x00, 0x00};
 
 // Constants for screen layout and fonts
 constexpr uint8_t SCREEN_CENTER_X = 32;
@@ -96,72 +124,103 @@ constexpr uint8_t CHANNEL_BOXES_Y = 50;
 constexpr uint8_t CHANNEL_BOX_WIDTH = 18;
 constexpr uint8_t CHANNEL_BOX_HEIGHT = 14;
 
+// Menu items for editing global parameters.
+enum ParamsMainPage : uint8_t {
+  PARAM_MAIN_TEMPO,
+  PARAM_MAIN_SOURCE,
+  PARAM_MAIN_RUN,
+  PARAM_MAIN_RESET,
+  PARAM_MAIN_PULSE,
+  PARAM_MAIN_ENCODER_DIR,
+  PARAM_MAIN_ROTATE_DISP,
+  PARAM_MAIN_SAVE_DATA,
+  PARAM_MAIN_LOAD_DATA,
+  PARAM_MAIN_RESET_STATE,
+  PARAM_MAIN_FACTORY_RESET,
+  PARAM_MAIN_LAST,
+};
+
+// Menu items for editing channel parameters.
+enum ParamsChannelPage : uint8_t {
+  PARAM_CH_MOD,
+  PARAM_CH_PROB,
+  PARAM_CH_DUTY,
+  PARAM_CH_OFFSET,
+  PARAM_CH_SWING,
+  PARAM_CH_CV1_DEST,
+  PARAM_CH_CV2_DEST,
+  PARAM_CH_LAST,
+};
+
 // Helper function to draw centered text
-void drawCenteredText(const char* text, int y, const uint8_t* font) {
-    gravity.display.setFont(font);
-    int textWidth = gravity.display.getStrWidth(text);
-    gravity.display.drawStr(SCREEN_CENTER_X - (textWidth / 2), y, text);
+void drawCenteredText(const char *text, int y, const uint8_t *font) {
+  gravity.display.setFont(font);
+  int textWidth = gravity.display.getStrWidth(text);
+  gravity.display.drawStr(SCREEN_CENTER_X - (textWidth / 2), y, text);
 }
 
 // Helper function to draw right-aligned text
-void drawRightAlignedText(const char* text, int y) {
-    int textWidth = gravity.display.getStrWidth(text);
-    int drawX = (SCREEN_WIDTH - textWidth) - MENU_BOX_PADDING;
-    gravity.display.drawStr(drawX, y, text);
+void drawRightAlignedText(const char *text, int y) {
+  int textWidth = gravity.display.getStrWidth(text);
+  int drawX = (SCREEN_WIDTH - textWidth) - MENU_BOX_PADDING;
+  gravity.display.drawStr(drawX, y, text);
 }
 
 void drawMainSelection() {
-    gravity.display.setDrawColor(1);
-    const int tickSize = 3;
-    const int mainWidth = SCREEN_WIDTH / 2;
-    const int mainHeight = 49;
-    gravity.display.drawLine(0, 0, tickSize, 0);
-    gravity.display.drawLine(0, 0, 0, tickSize);
-    gravity.display.drawLine(mainWidth, 0, mainWidth - tickSize, 0);
-    gravity.display.drawLine(mainWidth, 0, mainWidth, tickSize);
-    gravity.display.drawLine(mainWidth, mainHeight, mainWidth, mainHeight - tickSize);
-    gravity.display.drawLine(mainWidth, mainHeight, mainWidth - tickSize, mainHeight);
-    gravity.display.drawLine(0, mainHeight, tickSize, mainHeight);
-    gravity.display.drawLine(0, mainHeight, 0, mainHeight - tickSize);
-    gravity.display.setDrawColor(2);
+  gravity.display.setDrawColor(1);
+  const int tickSize = 3;
+  const int mainWidth = SCREEN_WIDTH / 2;
+  const int mainHeight = 49;
+  gravity.display.drawLine(0, 0, tickSize, 0);
+  gravity.display.drawLine(0, 0, 0, tickSize);
+  gravity.display.drawLine(mainWidth, 0, mainWidth - tickSize, 0);
+  gravity.display.drawLine(mainWidth, 0, mainWidth, tickSize);
+  gravity.display.drawLine(mainWidth, mainHeight, mainWidth,
+                           mainHeight - tickSize);
+  gravity.display.drawLine(mainWidth, mainHeight, mainWidth - tickSize,
+                           mainHeight);
+  gravity.display.drawLine(0, mainHeight, tickSize, mainHeight);
+  gravity.display.drawLine(0, mainHeight, 0, mainHeight - tickSize);
+  gravity.display.setDrawColor(2);
 }
 
 void drawMenuItems(String menu_items[], int menu_size) {
-    // Draw menu items
-    gravity.display.setFont(TEXT_FONT);
+  // Draw menu items
+  gravity.display.setFont(TEXT_FONT);
 
-    // Draw selected menu item box
-    int selectedBoxY = 0;
-    if (menu_size >= VISIBLE_MENU_ITEMS && app.selected_param == menu_size - 1) {
-        selectedBoxY = MENU_ITEM_HEIGHT * min(2, app.selected_param);
-    } else if (app.selected_param > 0) {
-        selectedBoxY = MENU_ITEM_HEIGHT;
-    }
+  // Draw selected menu item box
+  int selectedBoxY = 0;
+  if (menu_size >= VISIBLE_MENU_ITEMS && app.selected_param == menu_size - 1) {
+    selectedBoxY = MENU_ITEM_HEIGHT * min(2, app.selected_param);
+  } else if (app.selected_param > 0) {
+    selectedBoxY = MENU_ITEM_HEIGHT;
+  }
 
-    int boxX = MENU_BOX_WIDTH + 1;
-    int boxY = selectedBoxY + 2;
-    int boxWidth = MENU_BOX_WIDTH - 1;
-    int boxHeight = MENU_ITEM_HEIGHT + 1;
+  int boxX = MENU_BOX_WIDTH + 1;
+  int boxY = selectedBoxY + 2;
+  int boxWidth = MENU_BOX_WIDTH - 1;
+  int boxHeight = MENU_ITEM_HEIGHT + 1;
 
-    if (app.editing_param) {
-        gravity.display.drawBox(boxX, boxY, boxWidth, boxHeight);
-        drawMainSelection();
-    } else {
-        gravity.display.drawFrame(boxX, boxY, boxWidth, boxHeight);
-    }
+  if (app.editing_param) {
+    gravity.display.drawBox(boxX, boxY, boxWidth, boxHeight);
+    drawMainSelection();
+  } else {
+    gravity.display.drawFrame(boxX, boxY, boxWidth, boxHeight);
+  }
 
-    // Draw the visible menu items
-    int start_index = 0;
-    if (menu_size >= VISIBLE_MENU_ITEMS && app.selected_param == menu_size - 1) {
-        start_index = menu_size - VISIBLE_MENU_ITEMS;
-    } else if (app.selected_param > 0) {
-        start_index = app.selected_param - 1;
-    }
+  // Draw the visible menu items
+  int start_index = 0;
+  if (menu_size >= VISIBLE_MENU_ITEMS && app.selected_param == menu_size - 1) {
+    start_index = menu_size - VISIBLE_MENU_ITEMS;
+  } else if (app.selected_param > 0) {
+    start_index = app.selected_param - 1;
+  }
 
-    for (int i = 0; i < min(menu_size, VISIBLE_MENU_ITEMS); ++i) {
-        int idx = start_index + i;
-        drawRightAlignedText(menu_items[idx].c_str(), MENU_ITEM_HEIGHT * (i + 1) - 1);
-    }
+  for (int i = 0; i < min(menu_size, VISIBLE_MENU_ITEMS); ++i) {
+    int idx = start_index + i;
+    drawRightAlignedText(menu_items[idx].c_str(),
+                         MENU_ITEM_HEIGHT * (i + 1) - 1);
+  }
 }
 
 // Visual indicators for main section of screen.
@@ -170,266 +229,325 @@ inline void hollowTick() { gravity.display.drawBox(56, 4, 4, 4); }
 
 // Display an indicator when swing percentage matches a musical note.
 void swingDivisionMark() {
-    auto& ch = GetSelectedChannel();
-    switch (ch.getSwing()) {
-        case 58:  // 1/32nd
-        case 66:  // 1/16th
-        case 75:  // 1/8th
-            solidTick();
-            break;
-        case 54:  // 1/32nd tripplet
-        case 62:  // 1/16th tripplet
-        case 71:  // 1/8th tripplet
-            hollowTick();
-            break;
-    }
+  auto &ch = GetSelectedChannel();
+  switch (ch.getSwing()) {
+  case 58: // 1/32nd
+  case 66: // 1/16th
+  case 75: // 1/8th
+    solidTick();
+    break;
+  case 54: // 1/32nd tripplet
+  case 62: // 1/16th tripplet
+  case 71: // 1/8th tripplet
+    hollowTick();
+    break;
+  }
 }
 
 // Human friendly display value for save slot.
 String displaySaveSlot(int slot) {
-    if (slot >= 0 && slot < MAX_SAVE_SLOTS / 2) {
-        return String("A") + String(slot + 1);
-    } else if (slot >= MAX_SAVE_SLOTS / 2 && slot <= MAX_SAVE_SLOTS) {
-        return String("B") + String(slot - (MAX_SAVE_SLOTS / 2) + 1);
-    }
+  if (slot >= 0 && slot < StateManager::MAX_SAVE_SLOTS / 2) {
+    return String("A") + String(slot + 1);
+  } else if (slot >= StateManager::MAX_SAVE_SLOTS / 2 &&
+             slot <= StateManager::MAX_SAVE_SLOTS) {
+    return String("B") + String(slot - (StateManager::MAX_SAVE_SLOTS / 2) + 1);
+  }
 }
 
 // Main display functions
 
 void DisplayMainPage() {
-    gravity.display.setFontMode(1);
-    gravity.display.setDrawColor(2);
-    gravity.display.setFont(TEXT_FONT);
+  gravity.display.setFontMode(1);
+  gravity.display.setDrawColor(2);
+  gravity.display.setFont(TEXT_FONT);
 
-    // Display selected editable value
-    String mainText;
-    String subText;
+  // Display selected editable value
+  String mainText;
+  String subText;
 
-    switch (app.selected_param) {
-        case PARAM_MAIN_TEMPO:
-            // Serial MIDI is too unstable to display bpm in real time.
-            if (app.selected_source == Clock::SOURCE_EXTERNAL_MIDI) {
-                mainText = F("EXT");
-            } else {
-                mainText = String(gravity.clock.Tempo());
-            }
-            subText = F("BPM");
-            break;
-        case PARAM_MAIN_SOURCE:
-            mainText = F("EXT");
-            switch (app.selected_source) {
-                case Clock::SOURCE_INTERNAL:
-                    mainText = F("INT");
-                    subText = F("CLOCK");
-                    break;
-                case Clock::SOURCE_EXTERNAL_PPQN_24:
-                    subText = F("24 PPQN");
-                    break;
-                case Clock::SOURCE_EXTERNAL_PPQN_4:
-                    subText = F("4 PPQN");
-                    break;
-                case Clock::SOURCE_EXTERNAL_MIDI:
-                    subText = F("MIDI");
-                    break;
-            }
-            break;
-        case PARAM_MAIN_PULSE:
-            mainText = F("OUT");
-            switch (app.selected_pulse) {
-                case Clock::PULSE_NONE:
-                    subText = F("PULSE OFF");
-                    break;
-                case Clock::PULSE_PPQN_24:
-                    subText = F("24 PPQN PULSE");
-                    break;
-                case Clock::PULSE_PPQN_4:
-                    subText = F("4 PPQN PULSE");
-                    break;
-                case Clock::PULSE_PPQN_1:
-                    subText = F("1 PPQN PULSE");
-                    break;
-            }
-            break;
-        case PARAM_MAIN_ENCODER_DIR:
-            mainText = F("DIR");
-            subText = app.selected_sub_param == 0 ? F("DEFAULT") : F("REVERSED");
-            break;
-        case PARAM_MAIN_SAVE_DATA:
-        case PARAM_MAIN_LOAD_DATA:
-            if (app.selected_sub_param == MAX_SAVE_SLOTS) {
-                mainText = F("x");
-                subText = F("BACK TO MAIN");
-            } else {
-                // Indicate currently active slot.
-                if (app.selected_sub_param == app.selected_save_slot) {
-                    solidTick();
-                }
-                mainText = displaySaveSlot(app.selected_sub_param);
-                subText = (app.selected_param == PARAM_MAIN_SAVE_DATA)
-                              ? F("SAVE TO SLOT")
-                              : F("LOAD FROM SLOT");
-            }
-            break;
-        case PARAM_MAIN_RESET_STATE:
-            if (app.selected_sub_param == 0) {
-                mainText = F("RST");
-                subText = F("RESET ALL");
-            } else {
-                mainText = F("x");
-                subText = F("BACK TO MAIN");
-            }
+  switch (app.selected_param) {
+  case PARAM_MAIN_TEMPO:
+    // Serial MIDI is too unstable to display bpm in real time.
+    if (app.selected_source == Clock::SOURCE_EXTERNAL_MIDI) {
+      mainText = F("EXT");
+    } else {
+      mainText = String(gravity.clock.Tempo());
     }
+    subText = F("BPM");
+    break;
+  case PARAM_MAIN_SOURCE:
+    mainText = F("EXT");
+    switch (app.selected_source) {
+    case Clock::SOURCE_INTERNAL:
+      mainText = F("INT");
+      subText = F("CLOCK");
+      break;
+    case Clock::SOURCE_EXTERNAL_PPQN_24:
+      subText = F("24 PPQN");
+      break;
+    case Clock::SOURCE_EXTERNAL_PPQN_4:
+      subText = F("4 PPQN");
+      break;
+    case Clock::SOURCE_EXTERNAL_PPQN_2:
+      subText = F("2 PPQN");
+      break;
+    case Clock::SOURCE_EXTERNAL_PPQN_1:
+      subText = F("1 PPQN");
+      break;
+    case Clock::SOURCE_EXTERNAL_MIDI:
+      subText = F("MIDI");
+      break;
+    }
+    break;
+  case PARAM_MAIN_RUN:
+    mainText = F("RUN");
+    switch (app.cv_run) {
+    case 0:
+      subText = F("NONE");
+      break;
+    case 1:
+      subText = F("CV 1");
+      break;
+    case 2:
+      subText = F("CV 2");
+      break;
+    }
+    break;
+  case PARAM_MAIN_RESET:
+    mainText = F("RST");
+    switch (app.cv_reset) {
+    case 0:
+      subText = F("NONE");
+      break;
+    case 1:
+      subText = F("CV 1");
+      break;
+    case 2:
+      subText = F("CV 2");
+      break;
+    }
+    break;
+  case PARAM_MAIN_PULSE:
+    mainText = F("OUT");
+    switch (app.selected_pulse) {
+    case Clock::PULSE_NONE:
+      subText = F("PULSE OFF");
+      break;
+    case Clock::PULSE_PPQN_24:
+      subText = F("24 PPQN PULSE");
+      break;
+    case Clock::PULSE_PPQN_4:
+      subText = F("4 PPQN PULSE");
+      break;
+    case Clock::PULSE_PPQN_1:
+      subText = F("1 PPQN PULSE");
+      break;
+    }
+    break;
+  case PARAM_MAIN_ENCODER_DIR:
+    mainText = F("DIR");
+    subText = app.selected_sub_param == 0 ? F("DEFAULT") : F("REVERSED");
+    break;
+  case PARAM_MAIN_ROTATE_DISP:
+    mainText = F("DISP");
+    subText = app.selected_sub_param == 0 ? F("DEFAULT") : F("ROTATED");
+    break;
+  case PARAM_MAIN_SAVE_DATA:
+  case PARAM_MAIN_LOAD_DATA:
+    if (app.selected_sub_param == StateManager::MAX_SAVE_SLOTS) {
+      mainText = F("x");
+      subText = F("BACK TO MAIN");
+    } else {
+      // Indicate currently active slot.
+      if (app.selected_sub_param == app.selected_save_slot) {
+        solidTick();
+      }
+      mainText = displaySaveSlot(app.selected_sub_param);
+      subText = (app.selected_param == PARAM_MAIN_SAVE_DATA)
+                    ? F("SAVE TO SLOT")
+                    : F("LOAD FROM SLOT");
+    }
+    break;
+  case PARAM_MAIN_RESET_STATE:
+    if (app.selected_sub_param == 0) {
+      mainText = F("RST");
+      subText = F("RESET ALL");
+    } else {
+      mainText = F("x");
+      subText = F("BACK TO MAIN");
+    }
+    break;
+  case PARAM_MAIN_FACTORY_RESET:
+    if (app.selected_sub_param == 0) {
+      mainText = F("DEL");
+      subText = F("FACTORY RESET");
+    } else {
+      mainText = F("x");
+      subText = F("BACK TO MAIN");
+    }
+    break;
+  }
 
-    drawCenteredText(mainText.c_str(), MAIN_TEXT_Y, LARGE_FONT);
-    drawCenteredText(subText.c_str(), SUB_TEXT_Y, TEXT_FONT);
+  drawCenteredText(mainText.c_str(), MAIN_TEXT_Y, LARGE_FONT);
+  drawCenteredText(subText.c_str(), SUB_TEXT_Y, TEXT_FONT);
 
-    // Draw Main Page menu items
-    String menu_items[PARAM_MAIN_LAST] = {F("TEMPO"), F("SOURCE"), F("PULSE OUT"), F("ENCODER DIR"), F("SAVE"), F("LOAD"), F("RESET")};
-    drawMenuItems(menu_items, PARAM_MAIN_LAST);
+  // Draw Main Page menu items
+  String menu_items[PARAM_MAIN_LAST] = {
+      F("TEMPO"),     F("RUN"),         F("RST"),         F("SOURCE"),
+      F("PULSE OUT"), F("ENCODER DIR"), F("ROTATE DISP"), F("SAVE"),
+      F("LOAD"),      F("RESET"),       F("ERASE")};
+  drawMenuItems(menu_items, PARAM_MAIN_LAST);
 }
 
 void DisplayChannelPage() {
-    auto& ch = GetSelectedChannel();
+  auto &ch = GetSelectedChannel();
 
-    gravity.display.setFontMode(1);
-    gravity.display.setDrawColor(2);
+  gravity.display.setFontMode(1);
+  gravity.display.setDrawColor(2);
 
-    // Display selected editable value
-    String mainText;
-    String subText;
+  // Display selected editable value
+  String mainText;
+  String subText;
 
-    // When editing a param, just show the base value. When not editing show
-    // the value with cv mod.
-    bool withCvMod = !app.editing_param;
+  // When editing a param, just show the base value. When not editing show
+  // the value with cv mod.
+  bool withCvMod = !app.editing_param;
 
-    switch (app.selected_param) {
-        case PARAM_CH_MOD: {
-            int mod_value = ch.getClockMod(withCvMod);
-            if (mod_value > 1) {
-                mainText = F("/");
-                mainText += String(mod_value);
-                subText = F("DIVIDE");
-            } else {
-                mainText = F("x");
-                mainText += String(abs(mod_value));
-                subText = F("MULTIPLY");
-            }
-            break;
-        }
-        case PARAM_CH_PROB:
-            mainText = String(ch.getProbability(withCvMod)) + F("%");
-            subText = F("HIT CHANCE");
-            break;
-        case PARAM_CH_DUTY:
-            mainText = String(ch.getDutyCycle(withCvMod)) + F("%");
-            subText = F("PULSE WIDTH");
-            break;
-        case PARAM_CH_OFFSET:
-            mainText = String(ch.getOffset(withCvMod)) + F("%");
-            subText = F("SHIFT HIT");
-            break;
-        case PARAM_CH_SWING:
-            ch.getSwing() == 50
-                ? mainText = F("OFF")
-                : mainText = String(ch.getSwing(withCvMod)) + F("%");
-            subText = "DOWN BEAT";
-            swingDivisionMark();
-            break;
-        case PARAM_CH_EUC_STEPS:
-            mainText = String(ch.getSteps(withCvMod));
-            subText = "EUCLID STEPS";
-            break;
-        case PARAM_CH_EUC_HITS:
-            mainText = String(ch.getHits(withCvMod));
-            subText = "EUCLID HITS";
-            break;
-        case PARAM_CH_CV1_DEST:
-        case PARAM_CH_CV2_DEST: {
-            mainText = (app.selected_param == PARAM_CH_CV1_DEST) ? F("CV1") : F("CV2");
-            switch ((app.selected_param == PARAM_CH_CV1_DEST) ? ch.getCv1Dest() : ch.getCv2Dest()) {
-                case CV_DEST_NONE:
-                    subText = F("NONE");
-                    break;
-                case CV_DEST_MOD:
-                    subText = F("CLOCK MOD");
-                    break;
-                case CV_DEST_PROB:
-                    subText = F("PROBABILITY");
-                    break;
-                case CV_DEST_DUTY:
-                    subText = F("DUTY CYCLE");
-                    break;
-                case CV_DEST_OFFSET:
-                    subText = F("OFFSET");
-                    break;
-                case CV_DEST_SWING:
-                    subText = F("SWING");
-                    break;
-                case CV_DEST_EUC_STEPS:
-                    subText = F("EUCLID STEPS");
-                    break;
-                case CV_DEST_EUC_HITS:
-                    subText = F("EUCLID HITS");
-                    break;
-            }
-            break;
-        }
+  switch (app.selected_param) {
+  case PARAM_CH_MOD: {
+    int mod_value = ch.getClockMod(withCvMod);
+    if (mod_value > 1) {
+      mainText = F("/");
+      mainText += String(mod_value);
+      subText = F("DIVIDE");
+    } else {
+      mainText = F("x");
+      mainText += String(abs(mod_value));
+      subText = F("MULTIPLY");
     }
+    break;
+  }
+  case PARAM_CH_PROB:
+    mainText = String(ch.getProbability(withCvMod)) + F("%");
+    subText = F("HIT CHANCE");
+    break;
+  case PARAM_CH_DUTY:
+    mainText = String(ch.getDutyCycle(withCvMod)) + F("%");
+    subText = F("PULSE WIDTH");
+    break;
+  case PARAM_CH_OFFSET:
+    mainText = String(ch.getOffset(withCvMod)) + F("%");
+    subText = F("SHIFT HIT");
+    break;
+  case PARAM_CH_SWING:
+    ch.getSwing() == 50 ? mainText = F("OFF")
+                        : mainText = String(ch.getSwing(withCvMod)) + F("%");
+    subText = "DOWN BEAT";
+    swingDivisionMark();
+    break;
+  case PARAM_CH_CV1_DEST:
+  case PARAM_CH_CV2_DEST: {
+    mainText = (app.selected_param == PARAM_CH_CV1_DEST) ? F("CV1") : F("CV2");
+    switch ((app.selected_param == PARAM_CH_CV1_DEST) ? ch.getCv1Dest()
+                                                      : ch.getCv2Dest()) {
+    case CV_DEST_NONE:
+      subText = F("NONE");
+      break;
+    case CV_DEST_MOD:
+      subText = F("CLOCK MOD");
+      break;
+    case CV_DEST_PROB:
+      subText = F("PROBABILITY");
+      break;
+    case CV_DEST_DUTY:
+      subText = F("DUTY CYCLE");
+      break;
+    case CV_DEST_OFFSET:
+      subText = F("OFFSET");
+      break;
+    case CV_DEST_SWING:
+      subText = F("SWING");
+      break;
+    }
+    break;
+  }
+  }
 
-    drawCenteredText(mainText.c_str(), MAIN_TEXT_Y, LARGE_FONT);
-    drawCenteredText(subText.c_str(), SUB_TEXT_Y, TEXT_FONT);
+  drawCenteredText(mainText.c_str(), MAIN_TEXT_Y, LARGE_FONT);
+  drawCenteredText(subText.c_str(), SUB_TEXT_Y, TEXT_FONT);
 
-    // Draw Channel Page menu items
-    String menu_items[PARAM_CH_LAST] = {
-        F("MOD"), F("PROBABILITY"), F("DUTY"), F("OFFSET"), F("SWING"), F("EUCLID STEPS"),
-        F("EUCLID HITS"), F("CV1 MOD"), F("CV2 MOD")};
-    drawMenuItems(menu_items, PARAM_CH_LAST);
+  // Draw Channel Page menu items
+  String menu_items[PARAM_CH_LAST] = {
+      F("MOD"),   F("PROBABILITY"), F("DUTY"),   F("OFFSET"),
+      F("SWING"), F("CV1 MOD"),     F("CV2 MOD")};
+  drawMenuItems(menu_items, PARAM_CH_LAST);
 }
 
 void DisplaySelectedChannel() {
-    int boxX = CHANNEL_BOX_WIDTH;
-    int boxY = CHANNEL_BOXES_Y;
-    int boxWidth = CHANNEL_BOX_WIDTH;
-    int boxHeight = CHANNEL_BOX_HEIGHT;
-    int textOffset = 7;  // Half of font width
+  int boxX = CHANNEL_BOX_WIDTH;
+  int boxY = CHANNEL_BOXES_Y;
+  int boxWidth = CHANNEL_BOX_WIDTH;
+  int boxHeight = CHANNEL_BOX_HEIGHT;
+  int textOffset = 7; // Half of font width
 
-    // Draw top and right side of frame.
-    gravity.display.drawHLine(1, boxY, SCREEN_WIDTH - 2);
-    gravity.display.drawVLine(SCREEN_WIDTH - 2, boxY, boxHeight);
+  // Draw top and right side of frame.
+  gravity.display.drawHLine(1, boxY, SCREEN_WIDTH - 2);
+  gravity.display.drawVLine(SCREEN_WIDTH - 2, boxY, boxHeight);
 
-    for (int i = 0; i < Gravity::OUTPUT_COUNT + 1; i++) {
-        // Draw box frame or filled selected box.
-        gravity.display.setDrawColor(1);
-        (app.selected_channel == i)
-            ? gravity.display.drawBox(i * boxWidth, boxY, boxWidth, boxHeight)
-            : gravity.display.drawVLine(i * boxWidth, boxY, boxHeight);
+  for (int i = 0; i < Gravity::OUTPUT_COUNT + 1; i++) {
+    // Draw box frame or filled selected box.
+    gravity.display.setDrawColor(1);
+    (app.selected_channel == i)
+        ? gravity.display.drawBox(i * boxWidth, boxY, boxWidth, boxHeight)
+        : gravity.display.drawVLine(i * boxWidth, boxY, boxHeight);
 
-        // Draw clock status icon or each channel number.
-        gravity.display.setDrawColor(2);
-        if (i == 0) {
-            gravity.display.setBitmapMode(1);
-            auto icon = gravity.clock.IsPaused() ? pause_icon : play_icon;
-            gravity.display.drawXBMP(2, boxY, play_icon_width, play_icon_height, icon);
-        } else {
-            gravity.display.setFont(TEXT_FONT);
-            gravity.display.setCursor((i * boxWidth) + textOffset, SCREEN_HEIGHT - 3);
-            gravity.display.print(i);
-        }
+    // Draw clock status icon or each channel number.
+    gravity.display.setDrawColor(2);
+    if (i == 0) {
+      gravity.display.setBitmapMode(1);
+      auto icon = gravity.clock.IsPaused() ? pause_icon : play_icon;
+      gravity.display.drawXBMP(2, boxY, play_icon_width, play_icon_height,
+                               icon);
+    } else {
+      gravity.display.setFont(TEXT_FONT);
+      gravity.display.setCursor((i * boxWidth) + textOffset, SCREEN_HEIGHT - 3);
+      gravity.display.print(i);
     }
+  }
 }
 
 void UpdateDisplay() {
-    app.refresh_screen = false;
-    gravity.display.firstPage();
-    do {
-        if (app.selected_channel == 0) {
-            DisplayMainPage();
-        } else {
-            DisplayChannelPage();
-        }
-        // Global channel select UI.
-        DisplaySelectedChannel();
-    } while (gravity.display.nextPage());
+  app.refresh_screen = false;
+  gravity.display.firstPage();
+  do {
+    if (app.selected_channel == 0) {
+      DisplayMainPage();
+    } else {
+      DisplayChannelPage();
+    }
+    // Global channel select UI.
+    DisplaySelectedChannel();
+  } while (gravity.display.nextPage());
 }
 
-#endif  // DISPLAY_H
+void Bootsplash() {
+  gravity.display.firstPage();
+  do {
+    int textWidth;
+    String loadingText = F("LOADING....");
+    gravity.display.setFont(TEXT_FONT);
+
+    textWidth = gravity.display.getStrWidth(StateManager::SKETCH_NAME);
+    gravity.display.drawStr(16 + (textWidth / 2), 20,
+                            StateManager::SKETCH_NAME);
+
+    textWidth = gravity.display.getStrWidth(StateManager::SEMANTIC_VERSION);
+    gravity.display.drawStr(16 + (textWidth / 2), 32,
+                            StateManager::SEMANTIC_VERSION);
+
+    textWidth = gravity.display.getStrWidth(loadingText.c_str());
+    gravity.display.drawStr(26 + (textWidth / 2), 44, loadingText.c_str());
+  } while (gravity.display.nextPage());
+}
+
+#endif // DISPLAY_H

firmware/Gravity/save_state.cpp

@@ -15,151 +15,225 @@
 
 #include "app_state.h"
 
+// Define the constants for the current firmware.
+const char StateManager::SKETCH_NAME[] = "ALT GRAVITY";
+const char StateManager::SEMANTIC_VERSION[] =
+    "V2.0.1BETA1"; // NOTE: This should match the version in the
+                   // library.properties file.
+
+// Number of available save slots.
+const byte StateManager::MAX_SAVE_SLOTS = 10;
+const byte StateManager::TRANSIENT_SLOT = 10;
+
+// Define the minimum amount of time between EEPROM writes.
+const unsigned long StateManager::SAVE_DELAY_MS = 2000;
+
 // Calculate the starting address for EepromData, leaving space for metadata.
-static const int EEPROM_DATA_START_ADDR = sizeof(StateManager::Metadata);
+const int StateManager::METADATA_START_ADDR = 0;
+const int StateManager::EEPROM_DATA_START_ADDR = sizeof(StateManager::Metadata);
 
 StateManager::StateManager() : _isDirty(false), _lastChangeTime(0) {}
 
-bool StateManager::initialize(AppState& app) {
-    if (_isDataValid()) {
-        // Load data from the transient slot.
-        return loadData(app, MAX_SAVE_SLOTS);
-    } else {
-        // EEPROM does not contain save data for this firmware & version.
-        // Initialize eeprom and save default patter to all save slots.
-        reset(app);
-        _saveMetadata();
-        // MAX_SAVE_SLOTS slot is reserved for transient state.
-        for (int i = 0; i <= MAX_SAVE_SLOTS; i++) {
-            app.selected_save_slot = i;
-            _saveState(app, i);
-        }
-        return false;
-    }
+bool StateManager::initialize(AppState &app) {
+  noInterrupts();
+  bool success = false;
+  if (_isDataValid()) {
+    // Load global settings.
+    _loadMetadata(app);
+    // Load app data from the transient slot.
+    _loadState(app, TRANSIENT_SLOT);
+    success = true;
+  }
+  // EEPROM does not contain save data for this firmware & version.
+  else {
+    // Erase EEPROM and initialize state. Save default pattern to all save
+    // slots.
+    factoryReset(app);
+  }
+  interrupts();
+  return success;
 }
 
-bool StateManager::loadData(AppState& app, byte slot_index) {
-    if (slot_index >= MAX_SAVE_SLOTS) return false;
+bool StateManager::loadData(AppState &app, byte slot_index) {
+  // Check if slot_index is within max range + 1 for transient.
+  if (slot_index >= MAX_SAVE_SLOTS + 1)
+    return false;
 
-    _loadState(app, slot_index);
+  noInterrupts();
 
-    return true;
+  // Load the state data from the specified EEPROM slot and update the app state
+  // save slot.
+  _loadState(app, slot_index);
+  app.selected_save_slot = slot_index;
+  // Persist this change in the global metadata on next update.
+  _isDirty = true;
+
+  interrupts();
+  return true;
 }
 
-void StateManager::saveData(const AppState& app) {
-    if (app.selected_save_slot >= MAX_SAVE_SLOTS) return;
+// Save app state to user specified save slot.
+void StateManager::saveData(const AppState &app) {
+  noInterrupts();
+  // Check if slot_index is within max range + 1 for transient.
+  if (app.selected_save_slot >= MAX_SAVE_SLOTS + 1) {
+    interrupts();
+    return;
+  }
 
-    _saveState(app, app.selected_save_slot);
+  _saveState(app, app.selected_save_slot);
+  _saveMetadata(app);
+  _isDirty = false;
+  interrupts();
+}
+
+// Save transient state if it has changed and enough time has passed since last
+// save.
+void StateManager::update(const AppState &app) {
+  if (_isDirty && (millis() - _lastChangeTime > SAVE_DELAY_MS)) {
+    noInterrupts();
+    _saveState(app, TRANSIENT_SLOT);
+    _saveMetadata(app);
     _isDirty = false;
+    interrupts();
+  }
 }
 
-void StateManager::update(const AppState& app) {
-    if (_isDirty && (millis() - _lastChangeTime > SAVE_DELAY_MS)) {
-        // MAX_SAVE_SLOTS slot is reserved for transient state.
-        _saveState(app, MAX_SAVE_SLOTS);
-        _isDirty = false;
-    }
-}
+void StateManager::reset(AppState &app) {
+  noInterrupts();
 
-void StateManager::reset(AppState& app) {
-    app.tempo = Clock::DEFAULT_TEMPO;
-    app.encoder_reversed = false;
-    app.selected_param = 0;
-    app.selected_channel = 0;
-    app.selected_source = Clock::SOURCE_INTERNAL;
-    app.selected_pulse = Clock::PULSE_PPQN_24;
-    app.selected_save_slot = 0;
+  AppState default_app;
+  app.tempo = default_app.tempo;
+  app.selected_param = default_app.selected_param;
+  app.selected_channel = default_app.selected_channel;
+  app.selected_source = default_app.selected_source;
+  app.selected_pulse = default_app.selected_pulse;
+  app.cv_run = default_app.cv_run;
+  app.cv_reset = default_app.cv_reset;
 
-    for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
-        app.channel[i].Init();
-    }
+  for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
+    app.channel[i].Init();
+  }
 
-    _isDirty = false;
+  // Load global settings from Metadata
+  _loadMetadata(app);
+
+  _isDirty = false;
+  interrupts();
 }
 
 void StateManager::markDirty() {
-    _isDirty = true;
-    _lastChangeTime = millis();
+  _isDirty = true;
+  _lastChangeTime = millis();
+}
+
+// Erases all data in the EEPROM by writing 0 to every address.
+void StateManager::factoryReset(AppState &app) {
+  noInterrupts();
+  for (unsigned int i = 0; i < EEPROM.length(); i++) {
+    EEPROM.write(i, 0);
+  }
+  // Initialize eeprom and save default patter to all save slots.
+  _saveMetadata(app);
+  reset(app);
+  for (int i = 0; i < MAX_SAVE_SLOTS; i++) {
+    app.selected_save_slot = i;
+    _saveState(app, i);
+  }
+  _saveState(app, TRANSIENT_SLOT);
+  interrupts();
 }
 
 bool StateManager::_isDataValid() {
-    Metadata load_meta;
-    EEPROM.get(0, load_meta);
-    bool name_match = (strcmp(load_meta.sketch_name, SKETCH_NAME) == 0);
-    bool version_match = (load_meta.version == SKETCH_VERSION);
-    return name_match && version_match;
+  Metadata metadata;
+  EEPROM.get(METADATA_START_ADDR, metadata);
+  bool name_match = (strcmp(metadata.sketch_name, SKETCH_NAME) == 0);
+  bool version_match = (strcmp(metadata.version, SEMANTIC_VERSION) == 0);
+  return name_match && version_match;
 }
 
-void StateManager::_saveState(const AppState& app, byte slot_index) {
-    if (app.selected_save_slot >= MAX_SAVE_SLOTS) return;
+void StateManager::_saveState(const AppState &app, byte slot_index) {
+  // Check if slot_index is within max range + 1 for transient.
+  if (app.selected_save_slot >= MAX_SAVE_SLOTS + 1)
+    return;
 
-    noInterrupts();
-    static EepromData save_data;
+  static EepromData save_data;
 
-    save_data.tempo = app.tempo;
-    save_data.encoder_reversed = app.encoder_reversed;
-    save_data.selected_param = app.selected_param;
-    save_data.selected_channel = app.selected_channel;
-    save_data.selected_source = static_cast<byte>(app.selected_source);
-    save_data.selected_pulse = static_cast<byte>(app.selected_pulse);
-    save_data.selected_save_slot = app.selected_save_slot;
+  save_data.tempo = app.tempo;
+  save_data.selected_param = app.selected_param;
+  save_data.selected_channel = app.selected_channel;
+  save_data.selected_source = static_cast<byte>(app.selected_source);
+  save_data.selected_pulse = static_cast<byte>(app.selected_pulse);
+  save_data.cv_run = app.cv_run;
+  save_data.cv_reset = app.cv_reset;
 
-    for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
-        const auto& ch = app.channel[i];
-        auto& save_ch = save_data.channel_data[i];
-        save_ch.base_clock_mod_index = ch.getClockModIndex(false);
-        save_ch.base_probability = ch.getProbability(false);
-        save_ch.base_duty_cycle = ch.getDutyCycle(false);
-        save_ch.base_offset = ch.getOffset(false);
-        save_ch.base_swing = ch.getSwing(false);
-        save_ch.base_euc_steps = ch.getSteps(false);
-        save_ch.base_euc_hits = ch.getHits(false);
-        save_ch.cv1_dest = static_cast<byte>(ch.getCv1Dest());
-        save_ch.cv2_dest = static_cast<byte>(ch.getCv2Dest());
-    }
+  // TODO: break this out into a separate function. Save State should be
+  // broken out into global / per-channel save methods. When saving via
+  // "update" only save state for the current channel since other channels
+  // will not have changed when saving user edits.
+  for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
+    const auto &ch = app.channel[i];
+    auto &save_ch = save_data.channel_data[i];
+    save_ch.base_clock_mod_index = ch.getClockModIndex(false);
+    save_ch.base_probability = ch.getProbability(false);
+    save_ch.base_duty_cycle = ch.getDutyCycle(false);
+    save_ch.base_offset = ch.getOffset(false);
+    save_ch.cv1_dest = static_cast<byte>(ch.getCv1Dest());
+    save_ch.cv2_dest = static_cast<byte>(ch.getCv2Dest());
+  }
 
-    int address = EEPROM_DATA_START_ADDR + (slot_index * sizeof(EepromData));
-    EEPROM.put(address, save_data);
-    interrupts();
+  int address = EEPROM_DATA_START_ADDR + (slot_index * sizeof(EepromData));
+  EEPROM.put(address, save_data);
 }
 
-void StateManager::_loadState(AppState& app, byte slot_index) {
-    noInterrupts();
-    static EepromData load_data;
-    int address = EEPROM_DATA_START_ADDR + (slot_index * sizeof(EepromData));
-    EEPROM.get(address, load_data);
+void StateManager::_loadState(AppState &app, byte slot_index) {
+  // Check if slot_index is within max range + 1 for transient.
+  if (slot_index >= MAX_SAVE_SLOTS + 1)
+    return;
 
-    // Restore app state from loaded data.
-    app.tempo = load_data.tempo;
-    app.encoder_reversed = load_data.encoder_reversed;
-    app.selected_param = load_data.selected_param;
-    app.selected_channel = load_data.selected_channel;
-    app.selected_source = static_cast<Clock::Source>(load_data.selected_source);
-    app.selected_pulse = static_cast<Clock::Pulse>(load_data.selected_pulse);
-    app.selected_save_slot = slot_index;
+  static EepromData load_data;
+  int address = EEPROM_DATA_START_ADDR + (slot_index * sizeof(EepromData));
+  EEPROM.get(address, load_data);
 
-    for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
-        auto& ch = app.channel[i];
-        const auto& saved_ch_state = load_data.channel_data[i];
+  // Restore app state from loaded data.
+  app.tempo = load_data.tempo;
+  app.selected_param = load_data.selected_param;
+  app.selected_channel = load_data.selected_channel;
+  app.selected_source = static_cast<Clock::Source>(load_data.selected_source);
+  app.selected_pulse = static_cast<Clock::Pulse>(load_data.selected_pulse);
+  app.cv_run = load_data.cv_run;
+  app.cv_reset = load_data.cv_reset;
 
-        ch.setClockMod(saved_ch_state.base_clock_mod_index);
-        ch.setProbability(saved_ch_state.base_probability);
-        ch.setDutyCycle(saved_ch_state.base_duty_cycle);
-        ch.setOffset(saved_ch_state.base_offset);
-        ch.setSwing(saved_ch_state.base_swing);
-        ch.setSteps(saved_ch_state.base_euc_steps);
-        ch.setHits(saved_ch_state.base_euc_hits);
-        ch.setCv1Dest(static_cast<CvDestination>(saved_ch_state.cv1_dest));
-        ch.setCv2Dest(static_cast<CvDestination>(saved_ch_state.cv2_dest));
-    }
-    interrupts();
+  for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
+    auto &ch = app.channel[i];
+    const auto &saved_ch_state = load_data.channel_data[i];
+
+    ch.setClockMod(saved_ch_state.base_clock_mod_index);
+    ch.setProbability(saved_ch_state.base_probability);
+    ch.setDutyCycle(saved_ch_state.base_duty_cycle);
+    ch.setOffset(saved_ch_state.base_offset);
+    ch.setCv1Dest(static_cast<CvDestination>(saved_ch_state.cv1_dest));
+    ch.setCv2Dest(static_cast<CvDestination>(saved_ch_state.cv2_dest));
+  }
 }
 
-void StateManager::_saveMetadata() {
-    noInterrupts();
-    Metadata current_meta;
-    strcpy(current_meta.sketch_name, SKETCH_NAME);
-    current_meta.version = SKETCH_VERSION;
-    EEPROM.put(0, current_meta);
-    interrupts();
+void StateManager::_saveMetadata(const AppState &app) {
+  Metadata current_meta;
+  strcpy(current_meta.sketch_name, SKETCH_NAME);
+  strcpy(current_meta.version, SEMANTIC_VERSION);
+
+  // Global user settings
+  current_meta.selected_save_slot = app.selected_save_slot;
+  current_meta.encoder_reversed = app.encoder_reversed;
+  current_meta.rotate_display = app.rotate_display;
+
+  EEPROM.put(METADATA_START_ADDR, current_meta);
 }
+
+void StateManager::_loadMetadata(AppState &app) {
+  Metadata metadata;
+  EEPROM.get(METADATA_START_ADDR, metadata);
+  app.selected_save_slot = metadata.selected_save_slot;
+  app.encoder_reversed = metadata.encoder_reversed;
+  app.rotate_display = metadata.rotate_display;
+}

firmware/Gravity/save_state.h

@@ -13,82 +13,85 @@
 #define SAVE_STATE_H
 
 #include <Arduino.h>
-#include <gravity.h>
+#include <libGravity.h>
 
 // Forward-declare AppState to avoid circular dependencies.
 struct AppState;
 
-// Define the constants for the current firmware.
-const char SKETCH_NAME[] = "Gravity";
-const byte SKETCH_VERSION = 7;
-
-// Number of available save slots.
-const byte MAX_SAVE_SLOTS = 10;
-
-// Define the minimum amount of time between EEPROM writes.
-static const unsigned long SAVE_DELAY_MS = 2000;
-
 /**
- * @brief Manages saving and loading of the application state to and from EEPROM.
- * The number of user slots is defined by MAX_SAVE_SLOTS, and one additional slot
- * is reseved for transient state to persist state between power cycles before
- * state is explicitly saved to a user slot. Metadata is stored in the beginning
- * of the memory space which stores firmware version information to validate that
- * the data can be loaded into the current version of AppState.
+ * @brief Manages saving and loading of the application state to and from
+ * EEPROM. The number of user slots is defined by MAX_SAVE_SLOTS, and one
+ * additional slot is reseved for transient state to persist state between power
+ * cycles before state is explicitly saved to a user slot. Metadata is stored in
+ * the beginning of the memory space which stores firmware version information
+ * to validate that the data can be loaded into the current version of AppState.
  */
 class StateManager {
-   public:
-    StateManager();
+public:
+  static const char SKETCH_NAME[];
+  static const char SEMANTIC_VERSION[];
+  static const byte MAX_SAVE_SLOTS;
+  static const byte TRANSIENT_SLOT;
 
-    // Populate the AppState instance with values from EEPROM if they exist.
-    bool initialize(AppState& app);
-    // Load data from specified slot.
-    bool loadData(AppState& app, byte slot_index);
-    // Save data to specified slot.
-    void saveData(const AppState& app);
-    // Reset AppState instance back to default values.
-    void reset(AppState& app);
-    // Call from main loop, check if state has changed and needs to be saved.
-    void update(const AppState& app);
-    // Indicate that state has changed and we should save.
-    void markDirty();
+  StateManager();
 
-    // This struct holds the data that identifies the firmware version.
-    struct Metadata {
-        byte version;
-        char sketch_name[16];
-    };
-    struct ChannelState {
-        byte base_clock_mod_index;
-        byte base_probability;
-        byte base_duty_cycle;
-        byte base_offset;
-        byte base_swing;
-        byte base_euc_steps;
-        byte base_euc_hits;
-        byte cv1_dest;  // Cast the CvDestination enum as a byte for storage
-        byte cv2_dest;  // Cast the CvDestination enum as a byte for storage
-    };
-    // This struct holds all the parameters we want to save.
-    struct EepromData {
-        int tempo;
-        bool encoder_reversed;
-        byte selected_param;
-        byte selected_channel;
-        byte selected_source;
-        byte selected_pulse;
-        byte selected_save_slot;
-        ChannelState channel_data[Gravity::OUTPUT_COUNT];
-    };
+  // Populate the AppState instance with values from EEPROM if they exist.
+  bool initialize(AppState &app);
+  // Load data from specified slot.
+  bool loadData(AppState &app, byte slot_index);
+  // Save data to specified slot.
+  void saveData(const AppState &app);
+  // Reset AppState instance back to default values.
+  void reset(AppState &app);
+  // Call from main loop, check if state has changed and needs to be saved.
+  void update(const AppState &app);
+  // Indicate that state has changed and we should save.
+  void markDirty();
+  // Erase all data stored in the EEPROM.
+  void factoryReset(AppState &app);
 
-   private:
-    bool _isDataValid();
-    void _saveMetadata();
-    void _saveState(const AppState& app, byte slot_index);
-    void _loadState(AppState& app, byte slot_index);
+  // This struct holds the data that identifies the firmware version.
+  struct Metadata {
+    char sketch_name[16];
+    char version[16];
+    // Additional global/hardware settings
+    byte selected_save_slot;
+    bool encoder_reversed;
+    bool rotate_display;
+  };
+  struct ChannelState {
+    byte base_clock_mod_index;
+    byte base_probability;
+    byte base_duty_cycle;
+    byte base_offset;
+    byte cv1_dest; // Cast the CvDestination enum as a byte for storage
+    byte cv2_dest; // Cast the CvDestination enum as a byte for storage
+  };
+  // This struct holds all the parameters we want to save.
+  struct EepromData {
+    int tempo;
+    byte selected_param;
+    byte selected_channel;
+    byte selected_source;
+    byte selected_pulse;
+    byte cv_run;
+    byte cv_reset;
+    ChannelState channel_data[Gravity::OUTPUT_COUNT];
+  };
 
-    bool _isDirty;
-    unsigned long _lastChangeTime;
+private:
+  bool _isDataValid();
+  void _saveMetadata(const AppState &app);
+  void _loadMetadata(AppState &app);
+  void _saveState(const AppState &app, byte slot_index);
+  void _loadState(AppState &app, byte slot_index);
+
+  static const unsigned long SAVE_DELAY_MS;
+  static const int METADATA_START_ADDR;
+  static const int EEPROM_DATA_START_ADDR;
+
+  bool _isDirty;
+  unsigned long _lastChangeTime;
 };
 
-#endif  // SAVE_STATE_H
+#endif // SAVE_STATE_H

library.properties

@@ -0,0 +1,9 @@
+version=2.0.1beta1
+author=Adam Wonak
+maintainer=awonak <github.com/awonak>
+sentence=Hardware abstraction library for Sitka Instruments Gravity eurorack module
+category=Other
+license=MIT
+url=https://github.com/awonak/libGravity
+architectures=avr
+depends=uClock,RotaryEncoder,U8g2

src/analog_input.h

@@ -0,0 +1,104 @@
+/**
+ * @file analog_input.h
+ * @author Adam Wonak (https://github.com/awonak)
+ * @brief Class for interacting with analog inputs.
+ * @version 0.1
+ * @date 2025-05-23
+ *
+ * @copyright MIT - (c) 2025 - Adam Wonak - adam.wonak@gmail.com
+ *
+ */
+#ifndef ANALOG_INPUT_H
+#define ANALOG_INPUT_H
+
+const int MAX_INPUT = (1 << 10) - 1; // Max 10 bit analog read resolution.
+
+// estimated default calibration value
+const int CALIBRATED_LOW = -566;
+const int CALIBRATED_HIGH = 512;
+
+class AnalogInput {
+public:
+  static const int GATE_THRESHOLD = 0;
+
+  AnalogInput() {}
+  ~AnalogInput() {}
+
+  /**
+   * Initializes a analog input object.
+   *
+   * @param pin gpio pin for the analog input.
+   */
+  void Init(uint8_t pin) {
+    pinMode(pin, INPUT);
+    pin_ = pin;
+  }
+
+  /**
+   * Read the value of the analog input and set instance state.
+   *
+   */
+  void Process() {
+    old_read_ = read_;
+    int raw = analogRead(pin_);
+    read_ = map(raw, 0, MAX_INPUT, low_, high_);
+    read_ = constrain(read_ - offset_, -512, 512);
+    if (inverted_)
+      read_ = -read_;
+  }
+
+  // Set calibration values.
+
+  void AdjustCalibrationLow(int amount) { low_ += amount; }
+
+  void AdjustCalibrationHigh(int amount) { high_ += amount; }
+
+  void SetOffset(float percent) { offset_ = -(percent) * 512; }
+
+  void SetAttenuation(float percent) {
+    low_ = abs(percent) * CALIBRATED_LOW;
+    high_ = abs(percent) * CALIBRATED_HIGH;
+    inverted_ = percent < 0;
+  }
+
+  /**
+   * Get the current value of the analog input within a range of +/-512.
+   *
+   * @return read value within a range of +/-512.
+   *
+   */
+  inline int16_t Read() { return read_; }
+
+  /**
+   * Return the analog read value as voltage.
+   *
+   * @return A float representing the voltage (-5.0 to +5.0).
+   *
+   */
+  inline float Voltage() { return ((read_ / 512.0) * 5.0); }
+
+  /**
+   * Checks for a rising edge transition across a threshold.
+   *
+   * @param threshold The value that the input must cross.
+   * @return True if the value just crossed the threshold from below, false
+   * otherwise.
+   */
+  inline bool IsRisingEdge(int16_t threshold) const {
+    bool was_high = old_read_ > threshold;
+    bool is_high = read_ > threshold;
+    return is_high && !was_high;
+  }
+
+private:
+  uint8_t pin_;
+  int16_t read_;
+  uint16_t old_read_;
+  // calibration values.
+  int offset_ = 0;
+  int low_ = CALIBRATED_LOW;
+  int high_ = CALIBRATED_HIGH;
+  bool inverted_ = false;
+};
+
+#endif

src/clock.h

@@ -0,0 +1,186 @@
+/**
+ * @file clock.h
+ * @author Adam Wonak (https://github.com/awonak)
+ * @brief Wrapper Class for clock timing functions.
+ * @version 0.1
+ * @date 2025-05-04
+ *
+ * @copyright MIT - (c) 2025 - Adam Wonak - adam.wonak@gmail.com
+ *
+ */
+
+#ifndef CLOCK_H
+#define CLOCK_H
+
+#include <NeoHWSerial.h>
+
+#include "peripherials.h"
+#include "uClock/uClock.h"
+
+// MIDI clock, start, stop, and continue byte definitions - based on MIDI 1.0
+// Standards.
+#define MIDI_CLOCK 0xF8
+#define MIDI_START 0xFA
+#define MIDI_STOP 0xFC
+#define MIDI_CONTINUE 0xFB
+
+typedef void (*ExtCallback)(void);
+static ExtCallback extUserCallback = nullptr;
+static void serialEventNoop(uint8_t msg, uint8_t status) {}
+
+class Clock {
+public:
+  static constexpr int DEFAULT_TEMPO = 120;
+
+  enum Source {
+    SOURCE_INTERNAL,
+    SOURCE_EXTERNAL_PPQN_24,
+    SOURCE_EXTERNAL_PPQN_4,
+    SOURCE_EXTERNAL_PPQN_2,
+    SOURCE_EXTERNAL_PPQN_1,
+    SOURCE_EXTERNAL_MIDI,
+    SOURCE_LAST,
+  };
+
+  enum Pulse {
+    PULSE_NONE,
+    PULSE_PPQN_1,
+    PULSE_PPQN_4,
+    PULSE_PPQN_24,
+    PULSE_LAST,
+  };
+
+  void Init() {
+    NeoSerial.begin(31250);
+
+    // Initialize the clock library
+    uClock.init();
+    uClock.setClockMode(uClock.INTERNAL_CLOCK);
+    uClock.setOutputPPQN(uClock.PPQN_96);
+    uClock.setTempo(DEFAULT_TEMPO);
+
+    // MIDI events.
+    uClock.setOnClockStart(sendMIDIStart);
+    uClock.setOnClockStop(sendMIDIStop);
+    uClock.setOnSync24(sendMIDIClock);
+
+    uClock.start();
+  }
+
+  // Handle external clock tick and call user callback when receiving clock
+  // trigger (PPQN_4, PPQN_24, or MIDI).
+  void AttachExtHandler(void (*callback)()) {
+    extUserCallback = callback;
+    attachInterrupt(digitalPinToInterrupt(EXT_PIN), callback, RISING);
+  }
+
+  // Internal PPQN96 callback for all clock timer operations.
+  void AttachIntHandler(void (*callback)(uint32_t)) {
+    uClock.setOnOutputPPQN(callback);
+  }
+
+  // Set the source of the clock mode.
+  void SetSource(Source source) {
+    bool was_playing = !IsPaused();
+    uClock.stop();
+    // If we are changing the source from MIDI, disable the serial interrupt
+    // handler.
+    if (source_ == SOURCE_EXTERNAL_MIDI) {
+      NeoSerial.attachInterrupt(serialEventNoop);
+    }
+    source_ = source;
+    switch (source) {
+    case SOURCE_INTERNAL:
+      uClock.setClockMode(uClock.INTERNAL_CLOCK);
+      break;
+    case SOURCE_EXTERNAL_PPQN_24:
+      uClock.setClockMode(uClock.EXTERNAL_CLOCK);
+      uClock.setInputPPQN(uClock.PPQN_24);
+      break;
+    case SOURCE_EXTERNAL_PPQN_4:
+      uClock.setClockMode(uClock.EXTERNAL_CLOCK);
+      uClock.setInputPPQN(uClock.PPQN_4);
+      break;
+    case SOURCE_EXTERNAL_PPQN_2:
+      uClock.setClockMode(uClock.EXTERNAL_CLOCK);
+      uClock.setInputPPQN(uClock.PPQN_2);
+      break;
+    case SOURCE_EXTERNAL_PPQN_1:
+      uClock.setClockMode(uClock.EXTERNAL_CLOCK);
+      uClock.setInputPPQN(uClock.PPQN_1);
+      break;
+    case SOURCE_EXTERNAL_MIDI:
+      uClock.setClockMode(uClock.EXTERNAL_CLOCK);
+      uClock.setInputPPQN(uClock.PPQN_24);
+      NeoSerial.attachInterrupt(onSerialEvent);
+      break;
+    }
+    if (was_playing) {
+      uClock.start();
+    }
+  }
+
+  // Return true if the current selected source is externl (PPQN_4, PPQN_24, or
+  // MIDI).
+  bool ExternalSource() {
+    return uClock.getClockMode() == uClock.EXTERNAL_CLOCK;
+  }
+
+  // Return true if the current selected source is the internal master clock.
+  bool InternalSource() {
+    return uClock.getClockMode() == uClock.INTERNAL_CLOCK;
+  }
+
+  // Returns the current BPM tempo.
+  int Tempo() { return uClock.getTempo(); }
+
+  // Set the clock tempo to a int between 1 and 400.
+  void SetTempo(int tempo) { return uClock.setTempo(tempo); }
+
+  // Record an external clock tick received to process external/internal
+  // syncronization.
+  void Tick() { uClock.clockMe(); }
+
+  // Start the internal clock.
+  void Start() { uClock.start(); }
+
+  // Stop internal clock clock.
+  void Stop() { uClock.stop(); }
+
+  // Reset all clock counters to 0.
+  void Reset() { uClock.resetCounters(); }
+
+  // Returns true if the clock is not running.
+  bool IsPaused() { return uClock.clock_state == uClock.PAUSED; }
+
+private:
+  Source source_ = SOURCE_INTERNAL;
+
+  static void onSerialEvent(uint8_t msg, uint8_t status) {
+    // Note: uClock start and stop will echo to MIDI.
+    switch (msg) {
+    case MIDI_CLOCK:
+      if (extUserCallback) {
+        extUserCallback();
+      }
+      break;
+    case MIDI_STOP:
+      uClock.stop();
+      sendMIDIStop();
+      break;
+    case MIDI_START:
+    case MIDI_CONTINUE:
+      uClock.start();
+      sendMIDIStart();
+      break;
+    }
+  }
+
+  static void sendMIDIStart() { NeoSerial.write(MIDI_START); }
+
+  static void sendMIDIStop() { NeoSerial.write(MIDI_STOP); }
+
+  static void sendMIDIClock(uint32_t tick) { NeoSerial.write(MIDI_CLOCK); }
+};
+
+#endif

src/digital_output.h

@@ -0,0 +1,96 @@
+/**
+ * @file digital_output.h
+ * @author Adam Wonak (https://github.com/awonak)
+ * @brief Class for interacting with trigger / gate outputs.
+ * @version 0.1
+ * @date 2025-04-17
+ *
+ * @copyright MIT - (c) 2025 - Adam Wonak - adam.wonak@gmail.com
+ *
+ */
+#ifndef DIGITAL_OUTPUT_H
+#define DIGITAL_OUTPUT_H
+
+#include <Arduino.h>
+
+const byte DEFAULT_TRIGGER_DURATION_MS = 5;
+
+class DigitalOutput {
+public:
+  /**
+   * Initializes an CV Output paired object.
+   *
+   * @param cv_pin gpio pin for the cv output
+   */
+  void Init(uint8_t cv_pin) {
+    pinMode(cv_pin, OUTPUT); // Gate/Trigger Output
+    cv_pin_ = cv_pin;
+    trigger_duration_ = DEFAULT_TRIGGER_DURATION_MS;
+  }
+
+  /**
+   * Set the trigger duration in miliseconds.
+   *
+   * @param duration_ms trigger duration in miliseconds
+   */
+  void SetTriggerDuration(uint8_t duration_ms) {
+    trigger_duration_ = duration_ms;
+  }
+
+  /**
+   * Turn the CV and LED on or off according to the input state.
+   *
+   * @param state Arduino digital HIGH or LOW values.
+   */
+  inline void Update(uint8_t state) {
+    if (state == HIGH)
+      High(); // Rising
+    if (state == LOW)
+      Low(); // Falling
+  }
+
+  // Sets the cv output HIGH to about 5v.
+  inline void High() { update(HIGH); }
+
+  // Sets the cv output LOW to 0v.
+  inline void Low() { update(LOW); }
+
+  /**
+   * Begin a Trigger period for this output.
+   */
+  inline void Trigger() {
+    update(HIGH);
+    last_triggered_ = millis();
+  }
+
+  /**
+   * Return a bool representing the on/off state of the output.
+   */
+  inline void Process() {
+    // If trigger is HIGH and the trigger duration time has elapsed, set the
+    // output low.
+    if (on_ && (millis() - last_triggered_) >= trigger_duration_) {
+      update(LOW);
+    }
+  }
+
+  /**
+   * Return a bool representing the on/off state of the output.
+   *
+   * @return true if current cv state is high, false if current cv state is low
+   */
+  inline bool On() { return on_; }
+
+private:
+  unsigned long last_triggered_;
+  uint8_t trigger_duration_;
+  uint8_t cv_pin_;
+  bool on_;
+
+  void update(uint8_t state) {
+    digitalWrite(cv_pin_, state);
+    on_ = state == HIGH;
+  }
+};
+
+#endif

src/libGravity.cpp

@@ -1,5 +1,5 @@
 /**
- * @file gravity.cpp
+ * @file libGravity.cpp
  * @author Adam Wonak (https://github.com/awonak)
  * @brief Library for building custom scripts for the Sitka Instruments Gravity module.
  * @version 0.1
@@ -9,7 +9,7 @@
  *
  */
 
-#include "gravity.h"
+#include "libGravity.h"
 
 // Initialize the static pointer for the EncoderDir class to null. We want to
 // have a static pointer to decouple the ISR from the global gravity object.

src/libGravity.h

@@ -1,5 +1,5 @@
 /**
- * @file gravity.h
+ * @file libGravity.h
  * @author Adam Wonak (https://github.com/awonak)
  * @brief Library for building custom scripts for the Sitka Instruments Gravity module.
  * @version 0.1

src/uClock/uClock.cpp

@@ -32,7 +32,7 @@
  * DEALINGS IN THE SOFTWARE.
  */
 #include "uClock.h"
-#include "uClock/platforms/avr.h"
+#include "platforms/avr.h"
 
 //
 // Platform specific timer setup/control

uClock/uClock.h

@@ -1,180 +0,0 @@
-/*!
- *  @file       uClock.h
- *  Project     BPM clock generator for Arduino
- *  @brief      A Library to implement BPM clock tick calls using hardware interruption. Supported and tested on AVR boards(ATmega168/328, ATmega16u4/32u4 and ATmega2560) and ARM boards(RPI2040, Teensy, Seedstudio XIAO M0 and ESP32)
- *  @version    2.2.1
- *  @author     Romulo Silva
- *  @date       10/06/2017
- *  @license    MIT - (c) 2024 - Romulo Silva - contact@midilab.co
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included
- * in all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
- * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
- * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
- * DEALINGS IN THE SOFTWARE.
- */
-
-#ifndef __U_CLOCK_H__
-#define __U_CLOCK_H__
-
-#include <Arduino.h>
-#include <inttypes.h>
-
-namespace umodular { namespace clock {
-
-#define MIN_BPM	1
-#define MAX_BPM	400
-
-#define PHASE_FACTOR 16
-#define PLL_X 220
-
-#define SECS_PER_MIN  (60UL)
-#define SECS_PER_HOUR (3600UL)
-#define SECS_PER_DAY  (SECS_PER_HOUR * 24L)
-
-class uClockClass {
-
-    public:
-        enum ClockMode {
-            INTERNAL_CLOCK = 0,
-            EXTERNAL_CLOCK
-        };
-
-        enum ClockState {
-            PAUSED = 0,
-            STARTING,
-            STARTED
-        };
-
-        enum PPQNResolution {
-            PPQN_1 = 1,
-            PPQN_2 = 2,
-            PPQN_4 = 4,
-            PPQN_8 = 8,
-            PPQN_12 = 12,
-            PPQN_24 = 24,
-            PPQN_48 = 48,
-            PPQN_96 = 96,
-            PPQN_384 = 384,
-            PPQN_480 = 480,
-            PPQN_960 = 960
-        };
-
-        ClockState clock_state;
-
-        uClockClass();
-
-        void setOnOutputPPQN(void (*callback)(uint32_t tick)) {
-            onOutputPPQNCallback = callback;
-        }
-
-        void setOnSync24(void (*callback)(uint32_t tick)) {
-            onSync24Callback = callback;
-        }
-
-        void setOnClockStart(void (*callback)()) {
-            onClockStartCallback = callback;
-        }
-
-        void setOnClockStop(void (*callback)()) {
-            onClockStopCallback = callback;
-        }
-
-        void init();
-        void setOutputPPQN(PPQNResolution resolution);
-        void setInputPPQN(PPQNResolution resolution);
-
-        void handleTimerInt();
-        void handleExternalClock();
-        void resetCounters();
-
-        // external class control
-        void start();
-        void stop();
-        void pause();
-        void setTempo(float bpm);
-        float getTempo();
-
-        // for software timer implementation(fallback for no board support)
-        void run();
-
-        // external timming control
-        void setClockMode(ClockMode tempo_mode);
-        ClockMode getClockMode();
-        void clockMe();
-        // for smooth slave tempo calculate display you should raise the
-        // buffer_size of ext_interval_buffer in between 64 to 128. 254 max size.
-        // note: this doesn't impact on sync time, only display time getTempo()
-        // if you dont want to use it, it is default set it to 1 for memory save
-        void setExtIntervalBuffer(uint8_t buffer_size);
-
-        // elapsed time support
-        uint8_t getNumberOfSeconds(uint32_t time);
-        uint8_t getNumberOfMinutes(uint32_t time);
-        uint8_t getNumberOfHours(uint32_t time);
-        uint8_t getNumberOfDays(uint32_t time);
-        uint32_t getNowTimer();
-        uint32_t getPlayTime();
-
-        uint32_t bpmToMicroSeconds(float bpm);
-
-    private:
-        float inline freqToBpm(uint32_t freq);
-        float inline constrainBpm(float bpm);
-        void calculateReferencedata();
-
-        void (*onOutputPPQNCallback)(uint32_t tick);
-        void (*onSync24Callback)(uint32_t tick);
-        void (*onClockStartCallback)();
-        void (*onClockStopCallback)();
-
-        // clock input/output control
-        PPQNResolution output_ppqn = PPQN_96;
-        PPQNResolution input_ppqn = PPQN_24;
-        // output and internal counters, ticks and references
-        uint32_t tick;
-        uint32_t int_clock_tick;
-        uint8_t mod_clock_counter;
-        uint16_t mod_clock_ref;
-
-        uint8_t mod_sync24_counter;
-        uint16_t mod_sync24_ref;
-        uint32_t sync24_tick;
-
-        // external clock control
-        volatile uint32_t ext_clock_us;
-        volatile uint32_t ext_clock_tick;
-        volatile uint32_t ext_interval;
-        uint32_t last_interval;
-        uint32_t sync_interval;
-
-        float tempo;
-        uint32_t start_timer;
-        ClockMode clock_mode;
-
-        volatile uint32_t * ext_interval_buffer = nullptr;
-        uint8_t ext_interval_buffer_size;
-        uint16_t ext_interval_idx;
-};
-
-} } // end namespace umodular::clock
-
-extern umodular::clock::uClockClass uClock;
-
-extern "C" {
-    extern volatile uint32_t _millis;
-}
-
-#endif /* __U_CLOCK_H__ */