Add the functionality for calibrating the analog input. Add demo script for calibrating analog input.

analog_input.h

@@ -12,7 +12,6 @@
 #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:
@@ -36,20 +35,29 @@ class AnalogInput {
     void Process() {
         old_read_ = read_;
         int raw = analogRead(pin_);
-        read_ = map(raw, CALIBRATION_OFFSET, MAX_INPUT, 0, MAX_INPUT);
+        read_ = map(raw, calibration_offset_, MAX_INPUT, calibration_low_, calibration_high_);
     }
 
+    // Set calibration values.
+
+    void AdjustCalibrationLow(int val) { calibration_low_ += val; }
+    void AdjustCalibrationOffset(int val) { calibration_offset_ += val; }
+    void AdjustCalibrationHigh(int val) { calibration_high_ += val; }
+
     /**
-     * @brief Get the current value of the analog input.
+     * @brief Get the current value of the analog input within a range of +/-512.
      * 
      * @return InputState 
      */
-    inline uint16_t Read() { return read_; }
+    inline int16_t Read() { return read_; }
 
    private:
     uint8_t pin_;
-    uint16_t read_;
+    int16_t read_;
     uint16_t old_read_;
+    int calibration_offset_ = 0;
+    int calibration_low_ = -512;
+    int calibration_high_ = 512;
 };
 
 #endif

examples/calibrate_analog/calibrate_analog.ino

@@ -1,70 +1,99 @@
+/**
+ * Analog Input Calibration Script
+ * 
+ * Provide each CV input with a constant voltage of -5v, 0v, and 5v. For
+ * each config point, provide the appropriate voltage value and then adjust
+ * the encoder until you have the correct calibration value set.
+ * 
+ * With the arrow on the left side of the bar, provide a -5v signal and adjust
+ * the encoder until you read -512.
+ * 
+ * With the arrow in the center of the bar, provide a 0v signal and adjust the 
+ * encoder until you read 0.
+ * 
+ * With the arrow on the right side of the bar, provide a 5v signal and adjust
+ * the encoder until you read 512.
+ * 
+ * TODO: store the calibration value in EEPROM.
+ */
+
 #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);
+    gravity.encoder.AttachRotateHandler(CalibrateCV);
+    gravity.encoder.AttachPressHandler(NextCalibrationPoint);
 }
 
 // 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 NextCalibrationPoint() {
+    selected_param = (selected_param + 1) % 6;
 }
 
+void CalibrateCV(Direction dir, int val) {
+    AnalogInput* cv = (selected_param > 2) ? &gravity.cv2 : &gravity.cv1;
+    switch (selected_param % 3) {
+        case 0:
+            cv->AdjustCalibrationLow(val);
+            break;
+        case 1:
+            cv->AdjustCalibrationOffset(val);
+            break;
+        case 2:
+            cv->AdjustCalibrationHigh(val);
+            break;
+    }
+}
 
 void UpdateDisplay() {
     gravity.display.clearDisplay();
 
     int cv1 = gravity.cv1.Read();
     int cv2 = gravity.cv2.Read();
-    
-    gravity.display.setCursor(10, 10);
+
+    // CV1 Value
+    gravity.display.setCursor(10, 2);
     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);
+    gravity.display.drawRect(10, 12, 100, 10, 1);
+    if (cv1 > 0) {
+        // 0 to 512
+        int x = (float(cv1) / 512.0) * 50;
+        gravity.display.fillRect(60, 12, x, 10, 1);
     } else {
-        int x = (float(512 - cv1) / 512.0) * 50; 
-        gravity.display.fillRect(60-x, 22, x, 10, 1);
+        // -512 to 0
+        int x = (float(abs(cv1)) / 512.0) * 50;
+        gravity.display.fillRect(60 - x, 12, x, 10, 1);
     }
 
-    gravity.display.setCursor(10, 42);
+    // CV2 Value
+    gravity.display.setCursor(10, 32);
     gravity.display.print(F("CV2: "));
     gravity.display.print(cv2);
-    if (cv2 >= 512) {
-        int x = (float(cv2 - 512) / 512.0) * 50; 
+
+    gravity.display.drawRect(10, 42, 100, 10, 1);
+    if (cv2 >= 0) {
+        int x = (float(cv2) / 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);
+        int x = (float(abs(cv2)) / 512.0) * 50;
+        gravity.display.fillRect(60 - x, 42, x, 10, 1);
     }
 
+    // Selected calibration point.
+    int left = 10 + (48 * (selected_param % 3));
+    int top = 22 + (selected_param > 2 ? 32 : 0);
+    gravity.display.drawChar(left, top, 0x1E, 1, 0, 1);
+
     gravity.display.display();
 }