From 7f9ad7e00d4bb2effd431651eed1fb7abd02fb01 Mon Sep 17 00:00:00 2001
From: Adam Wonak <adam.wonak@gmail.com>
Date: Fri, 23 May 2025 21:36:18 -0700
Subject: [PATCH] basic implementation of analog inputs and test script

---
 analog_input.h                                | 55 +++++++++++++++
 .../calibrate_analog/calibrate_analog.ino     | 70 +++++++++++++++++++
 gravity.cpp                                   |  5 ++
 gravity.h                                     |  3 +
 4 files changed, 133 insertions(+)
 create mode 100644 analog_input.h
 create mode 100644 examples/calibrate_analog/calibrate_analog.ino

diff --git a/analog_input.h b/analog_input.h
new file mode 100644
index 0000000..d05cefe
--- /dev/null
+++ b/analog_input.h
@@ -0,0 +1,55 @@
+/**
+ * @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 Copyright (c) 2025
+ * 
+ */
+#ifndef ANALOG_INPUT_H
+#define ANALOG_INPUT_H
+
+const int MAX_INPUT = (1 << 10) - 1;  // Max 10 bit analog read resolution.
+const int CALIBRATION_OFFSET = 15;
+
+class AnalogInput {
+   public:
+    AnalogInput() {}
+    ~AnalogInput() {}
+
+    /**
+    * @brief Initializes a analog input object.
+    * 
+    * @param pin gpio pin for the analog input.
+    */
+    void Init(uint8_t pin) {
+        pinMode(pin, INPUT);
+        pin_ = pin;
+    }
+
+    /**
+     * @brief Read the value of the analog input.
+     * 
+     */
+    void Process() {
+        old_read_ = read_;
+        int raw = analogRead(pin_);
+        read_ = map(raw, CALIBRATION_OFFSET, MAX_INPUT, 0, MAX_INPUT);
+    }
+
+    /**
+     * @brief Get the current value of the analog input.
+     * 
+     * @return InputState 
+     */
+    inline uint16_t Read() { return read_; }
+
+   private:
+    uint8_t pin_;
+    uint16_t read_;
+    uint16_t old_read_;
+};
+
+#endif
diff --git a/examples/calibrate_analog/calibrate_analog.ino b/examples/calibrate_analog/calibrate_analog.ino
new file mode 100644
index 0000000..148c152
--- /dev/null
+++ b/examples/calibrate_analog/calibrate_analog.ino
@@ -0,0 +1,70 @@
+#include "gravity.h"
+
+byte idx = 0;
+bool reversed = false;
+bool freeze = false;
+byte selected_param = 0;
+
+// Initialize the gravity library and attach your handlers in the setup method.
+void setup() {
+    // Initialize Gravity.
+    gravity.Init();
+
+    // Attach handlers.
+    gravity.clock.AttachIntHandler(IntClock);
+}
+
+// The loop method must always call `gravity.Process()` to read any peripherial state changes.
+void loop() {
+    gravity.Process();
+
+    UpdateDisplay();
+}
+
+// The rest of the code is your apps logic!
+
+void IntClock(uint32_t tick) {
+    if (tick % 12 == 0  && ! freeze) {
+        gravity.outputs[idx].Low();
+        if (reversed) {
+            idx = (idx == 0) ? OUTPUT_COUNT - 1 : idx - 1;
+        } else {
+            idx = (idx + 1) % OUTPUT_COUNT;
+        }
+        gravity.outputs[idx].High();
+    }
+}
+
+
+void UpdateDisplay() {
+    gravity.display.clearDisplay();
+
+    int cv1 = gravity.cv1.Read();
+    int cv2 = gravity.cv2.Read();
+    
+    gravity.display.setCursor(10, 10);
+    gravity.display.print(F("CV1: "));
+    gravity.display.print(cv1);
+
+    gravity.display.drawRect(10, 22, 100, 10, 1);
+    if (cv1 >= 512) {
+        int x = (float(cv1 - 512) / 512.0) * 50; 
+        gravity.display.fillRect(60, 22, x, 10, 1);
+    } else {
+        int x = (float(512 - cv1) / 512.0) * 50; 
+        gravity.display.fillRect(60-x, 22, x, 10, 1);
+    }
+
+    gravity.display.setCursor(10, 42);
+    gravity.display.print(F("CV2: "));
+    gravity.display.print(cv2);
+    if (cv2 >= 512) {
+        int x = (float(cv2 - 512) / 512.0) * 50; 
+        gravity.display.fillRect(60, 42, x, 10, 1);
+    } else {
+        int x = (float(512 - cv2) / 512.0) * 50; 
+        gravity.display.fillRect(60-x, 42, x, 10, 1);
+    }
+
+    gravity.display.display();
+}
\ No newline at end of file
diff --git a/gravity.cpp b/gravity.cpp
index 7a0df8a..2cfbb8b 100644
--- a/gravity.cpp
+++ b/gravity.cpp
@@ -26,6 +26,9 @@ void Gravity::InitInputs() {
     shift_button.Init(SHIFT_BTN_PIN);
     play_button.Init(PLAY_BTN_PIN);
 
+    cv1.Init(CV1_PIN);
+    cv2.Init(CV2_PIN);
+
     // Pin Change Interrupts for Encoder.
     // Thanks to https://dronebotworkshop.com/interrupts/
 
@@ -62,6 +65,8 @@ void Gravity::Process() {
     shift_button.Process();
     play_button.Process();
     encoder.Process();
+    cv1.Process();
+    cv2.Process();
 
     // Update Output states.
     for (int i; i < OUTPUT_COUNT; i++) {
diff --git a/gravity.h b/gravity.h
index 70f67d4..698ebcb 100644
--- a/gravity.h
+++ b/gravity.h
@@ -5,6 +5,7 @@
 #include <Adafruit_SSD1306.h>
 #include <Arduino.h>
 
+#include "analog_input.h"
 #include "button.h"
 #include "clock.h"
 #include "digital_output.h"
@@ -33,6 +34,8 @@ class Gravity {
     EncoderDir encoder;                   // Rotary encoder with button instance
     Button shift_button;
     Button play_button;
+    AnalogInput cv1;
+    AnalogInput cv2;
 
    private:
     void InitClock();