Lots of changes and optimizations

- add reverse encoder menu option and save state
- improve usage of EncoderDir in ISR with pointer to instance and static isr() method.
- reduce u8g2 memory usage by using single page buffer
- improve save state behavor by using a mutex flag and update check with debounce in main loop
- make saving to EEPROM safer by wrapping put calls with noInterrupts()

encoder_dir.h

@@ -34,7 +34,9 @@ class EncoderDir {
 
    public:
     EncoderDir() : encoder_(ENCODER_PIN1, ENCODER_PIN2, RotaryEncoder::LatchMode::FOUR3),
-                   button_(ENCODER_SW_PIN) {}
+                   button_(ENCODER_SW_PIN) {
+        _instance = this;
+    }
     ~EncoderDir() {}
 
     // Set to true if the encoder read direction should be reversed.
@@ -81,15 +83,19 @@ class EncoderDir {
         }
     }
 
-    // Read the encoder state and update the read position.
+    static void isr() {
-    void UpdateEncoder() {
+        // If the instance has been created, call its tick() method.
-        encoder_.tick();
+        if (_instance) {
+            _instance->encoder_.tick();
+        }
     }
 
    private:
+    static EncoderDir* _instance;
+
     int previous_pos_;
     bool rotated_while_held_;
-    bool reversed_ = true;
+    bool reversed_ = false;
     RotaryEncoder encoder_;
     Button button_;
 
@@ -115,15 +121,18 @@ class EncoderDir {
             change *= 2;
         }
 
+        if (reversed_) {
+            change = -(change);
+        }
         return change;
     }
 
     inline Direction rotate_(int dir, bool reversed) {
         switch (dir) {
             case 1:
-                return (reversed) ? DIRECTION_INCREMENT : DIRECTION_DECREMENT;
-            case -1:
                 return (reversed) ? DIRECTION_DECREMENT : DIRECTION_INCREMENT;
+            case -1:
+                return (reversed) ? DIRECTION_INCREMENT : DIRECTION_DECREMENT;
             default:
                 return DIRECTION_UNCHANGED;
         }

examples/Gravity/Gravity.ino

@@ -30,6 +30,7 @@ StateManager stateManager;
 enum ParamsMainPage {
     PARAM_MAIN_TEMPO,
     PARAM_MAIN_SOURCE,
+    PARAM_MAIN_ENCODER_DIR,
     PARAM_MAIN_RESET_STATE,
     PARAM_MAIN_LAST,
 };
@@ -139,6 +140,9 @@ void loop() {
         app.channel[i].applyCvMod(cv1, cv2);
     }
 
+    // Check for dirty state eligible to be saved.
+    stateManager.update(app);
+
     if (app.refresh_screen) {
         UpdateDisplay();
     }
@@ -194,19 +198,23 @@ void HandleEncoderPressed() {
     // Check if leaving editing mode should apply a selection.
     if (app.editing_param) {
         if (app.selected_channel == 0) {  // main page
+            if (app.selected_param == PARAM_MAIN_ENCODER_DIR) {
+                bool reversed = app.selected_sub_param == 1;
+                gravity.encoder.SetReverseDirection(reversed);
+            }
             // Reset state
             if (app.selected_param == PARAM_MAIN_RESET_STATE) {
                 if (app.selected_sub_param == 0) {  // Reset
                     stateManager.reset(app);
-                    // stateManager.initialize(app);
                     InitAppState(app);
                 }
             }
         }
+        // Only mark dirty when leaving editing mode.
+        stateManager.markDirty();
     }
     app.selected_sub_param = 0;
     app.editing_param = !app.editing_param;
-    stateManager.save(app);
     app.refresh_screen = true;
 }
 
@@ -223,7 +231,6 @@ void HandleRotate(Direction dir, int val) {
             editChannelParameter(val);
         }
     }
-    stateManager.save(app);
     app.refresh_screen = true;
 }
 
@@ -234,7 +241,7 @@ void HandlePressedRotate(Direction dir, int val) {
         app.selected_channel--;
     }
     app.selected_param = 0;
-    stateManager.save(app);
+    stateManager.markDirty();
     app.refresh_screen = true;
 }
 
@@ -255,6 +262,9 @@ void editMainParameter(int val) {
             gravity.clock.SetSource(app.selected_source);
             break;
         }
+        case PARAM_MAIN_ENCODER_DIR:
+            updateSelection(app.selected_sub_param, val, 2);
+            break;
         case PARAM_MAIN_RESET_STATE:
             updateSelection(app.selected_sub_param, val, 2);
             break;
@@ -303,6 +313,7 @@ void updateSelection(int& param, int change, int maxValue) {
 void InitAppState(AppState& app) {
     gravity.clock.SetTempo(app.tempo);
     gravity.clock.SetSource(app.selected_source);
+    gravity.encoder.SetReverseDirection(app.encoder_reversed);
 }
 
 Channel& GetSelectedChannel() {
@@ -384,6 +395,10 @@ void DisplayMainPage() {
                     break;
             }
             break;
+        case PARAM_MAIN_ENCODER_DIR:
+            sprintf(mainText, "%s", "DIR");
+            subText = app.selected_sub_param == 0 ? "DEFAULT" : "REVERSED";
+            break;
         case PARAM_MAIN_RESET_STATE:
             sprintf(mainText, "%s", "RST");
             subText = app.selected_sub_param == 0 ? "RESET ALL" : "BACK";
@@ -394,7 +409,7 @@ void DisplayMainPage() {
     drawCenteredText(subText, SUB_TEXT_Y, TEXT_FONT);
 
     // Draw Main Page menu items
-    const char* menu_items[PARAM_MAIN_LAST] = {"TEMPO", "SOURCE", "RESET"};
+    const char* menu_items[PARAM_MAIN_LAST] = {"TEMPO", "SOURCE", "ENCODER DIR", "RESET"};
     drawMenuItems(menu_items, PARAM_MAIN_LAST);
 }
 

examples/Gravity/app_state.h

@@ -8,6 +8,7 @@
 // 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;
     int selected_param = 0;

examples/Gravity/save_state.cpp

@@ -4,13 +4,16 @@
 
 #include "app_state.h"
 
+StateManager::StateManager() : _isDirty(false), _lastChangeTime(0) {}
+
 bool StateManager::initialize(AppState& app) {
     if (isDataValid()) {
-        EepromData load_data;
+        static EepromData load_data;
         EEPROM.get(sizeof(Metadata), load_data);
 
         // Restore main app state
         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);
@@ -30,41 +33,21 @@ bool StateManager::initialize(AppState& app) {
 
         return true;
     } else {
-        writeMetadata();
+        reset(app);
-        save(app);  // Save the initial default state
         return false;
     }
 }
 
 void StateManager::save(const AppState& app) {
-    EepromData save_data;
+    // Ensure interrupts do not cause corrupt data writes.
-
+    noInterrupts();
-    // Populate main app state
+    _save_worker(app);
-    save_data.tempo = app.tempo;
+    interrupts();
-    save_data.selected_param = app.selected_param;
-    save_data.selected_channel = app.selected_channel;
-    save_data.selected_source = static_cast<byte>(app.selected_source);
-
-    // Loop through and populate each channel's state
-    for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
-        const auto& ch = app.channel[i];
-        auto& saved_ch_state = save_data.channel_data[i];
-
-        // Use the getters with 'withCvMod = false' to get the base values
-        saved_ch_state.base_clock_mod_index = ch.getClockModIndex(false);
-        saved_ch_state.base_probability = ch.getProbability(false);
-        saved_ch_state.base_duty_cycle = ch.getDutyCycle(false);
-        saved_ch_state.base_offset = ch.getOffset(false);
-        saved_ch_state.cv_source = static_cast<byte>(ch.getCvSource());
-        saved_ch_state.cv_destination = static_cast<byte>(ch.getCvDestination());
-    }
-
-    // Write the entire state struct to EEPROM
-    EEPROM.put(sizeof(Metadata), save_data);
 }
 
 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;
@@ -73,8 +56,25 @@ void StateManager::reset(AppState& app) {
         app.channel[i].Init();
     }
 
-    writeMetadata();
+    noInterrupts();
+    _metadata_worker();  // Write the new metadata
+    _save_worker(app);   // Write the new (default) app state
+    interrupts();
+
+    _isDirty = false;
+}
+
+void StateManager::update(const AppState& app) {
+    // Check if a save is pending and if enough time has passed.
+    if (_isDirty && (millis() - _lastChangeTime > SAVE_DELAY_MS)) {
         save(app);
+        _isDirty = false;  // Clear the flag, we are now "clean".
+    }
+}
+
+void StateManager::markDirty() {
+    _isDirty = true;
+    _lastChangeTime = millis();
 }
 
 bool StateManager::isDataValid() {
@@ -85,9 +85,35 @@ bool StateManager::isDataValid() {
     return nameMatch && versionMatch;
 }
 
-void StateManager::writeMetadata() {
+void StateManager::_save_worker(const AppState& app) {
-    Metadata save_meta;
+    static EepromData save_data;
-    strcpy(save_meta.sketchName, CURRENT_SKETCH_NAME);
+
-    save_meta.version = CURRENT_SKETCH_VERSION;
+    // Populate main app state
-    EEPROM.put(0, save_meta);
+    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);
+
+    // Loop through and populate each channel's state
+    for (int i = 0; i < Gravity::OUTPUT_COUNT; i++) {
+        const auto& ch = app.channel[i];
+        auto& save_ch = save_data.channel_data[i];
+
+        // Use the getters with 'withCvMod = false' to get the base values
+        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.cv_source = static_cast<byte>(ch.getCvSource());
+        save_ch.cv_destination = static_cast<byte>(ch.getCvDestination());
+    }
+    EEPROM.put(sizeof(Metadata), save_data);
+}
+
+void StateManager::_metadata_worker() {
+    Metadata currentMeta;
+    strcpy(currentMeta.sketchName, CURRENT_SKETCH_NAME);
+    currentMeta.version = CURRENT_SKETCH_VERSION;
+    EEPROM.put(0, currentMeta);
 }

examples/Gravity/save_state.h

@@ -16,15 +16,20 @@ const float CURRENT_SKETCH_VERSION = 0.2f;
  */
 class StateManager {
    public:
+    StateManager();
+
     bool initialize(AppState& app);
-    void save(const AppState& app);
     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();
 
    private:
     // This struct holds the data that identifies the firmware version.
     struct Metadata {
         char sketchName[16];
-        float version;
+        byte version;
     };
     struct ChannelState {
         byte base_clock_mod_index;
@@ -37,14 +42,23 @@ class StateManager {
     // 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;
         ChannelState channel_data[Gravity::OUTPUT_COUNT];
     };
 
+    void save(const AppState& app);
+
     bool isDataValid();
-    void writeMetadata();
+    void _save_worker(const AppState& app);
+    void _metadata_worker();
+
+    bool _isDirty;
+    unsigned long _lastChangeTime;
+    static const unsigned long SAVE_DELAY_MS = 2000;
+
 };
 
 #endif  // SAVE_STATE_H

gravity.cpp

@@ -11,6 +11,9 @@
 
 #include "gravity.h"
 
+// Initialize the static pointer for the EncoderDir class to null.
+EncoderDir* EncoderDir::_instance = nullptr;
+
 void Gravity::Init() {
     initClock();
     initInputs();
@@ -68,18 +71,13 @@ void Gravity::Process() {
     }
 }
 
-void ReadEncoder() {
-    gravity.encoder.UpdateEncoder();
-}
-
-// Define Encoder pin ISR.
-// Pin Change Interrupt on Port C (D17/A3).
-ISR(PCINT2_vect) {
-    ReadEncoder();
-};
 // Pin Change Interrupt on Port D (D4).
+ISR(PCINT2_vect) {
+    EncoderDir::isr();
+};
+// Pin Change Interrupt on Port C (D17/A3).
 ISR(PCINT1_vect) {
-    ReadEncoder();
+    EncoderDir::isr();
 };
 
 // Singleton

gravity.h

@@ -29,7 +29,7 @@ class Gravity {
     // Polling check for state change of inputs and outputs.
     void Process();
 
-    U8G2_SSD1306_128X64_NONAME_2_HW_I2C display;  // OLED display object.
+    U8G2_SSD1306_128X64_NONAME_1_HW_I2C display;  // OLED display object.
     Clock clock;                                  // Clock source wrapper.
     DigitalOutput outputs[OUTPUT_COUNT];          // An array containing each Output object.
     EncoderDir encoder;                           // Rotary encoder with button instance