Rotary encoder

AudioThread.cpp

@@ -17,12 +17,6 @@ const int16_t AMPLITUDE = 16383; // Use a lower amplitude to avoid clipping (max
 I2S i2s(OUTPUT);
 
 // --- Synthesizer State ---
-// Frequencies for a C-Major scale to pick from
-const float NOTE_FREQUENCIES[] = {
-  261.63, 293.66, 329.63, 349.23, 392.00, 440.00, 493.88, 523.25
-};
-const int NUM_NOTES = sizeof(NOTE_FREQUENCIES) / sizeof(NOTE_FREQUENCIES[0]);
-
 float currentFrequency = 440.0f;
 double phase = 0.0;
 unsigned long lastNoteChangeTime = 0;
@@ -50,8 +44,8 @@ void loopAudio() {
   // Every 500ms, pick a new random note to play
   if (now - lastNoteChangeTime > 500) {
     lastNoteChangeTime = now;
-    int noteIndex = random(0, NUM_NOTES);
+    int noteIndex = random(0, SCALES[currentScaleIndex].numNotes);
-    currentFrequency = NOTE_FREQUENCIES[noteIndex];
+    currentFrequency = SCALES[currentScaleIndex].frequencies[noteIndex];
     Serial.println("Playing note: " + String(currentFrequency) + " Hz");
   }
 

SharedState.cpp

@@ -3,3 +3,12 @@
 volatile unsigned long lastLoop0Time = 0;
 volatile unsigned long lastLoop1Time = 0;
 volatile bool watchdogActive = false;
+
+const Scale SCALES[] = {
+  { "C Major",      { 261.63, 293.66, 329.63, 349.23, 392.00, 440.00, 493.88, 523.25 }, 8 },
+  { "C Minor",      { 261.63, 293.66, 311.13, 349.23, 392.00, 415.30, 466.16, 523.25 }, 8 },
+  { "Pentatonic",   { 261.63, 293.66, 329.63, 392.00, 440.00, 523.25, 587.33, 659.25 }, 8 },
+  { "Blues",        { 261.63, 311.13, 349.23, 369.99, 392.00, 466.16, 523.25, 587.33 }, 8 }
+};
+const int NUM_SCALES = sizeof(SCALES) / sizeof(SCALES[0]);
+volatile int currentScaleIndex = 0;

SharedState.h

@@ -7,4 +7,14 @@ extern volatile unsigned long lastLoop0Time;
 extern volatile unsigned long lastLoop1Time;
 extern volatile bool watchdogActive;
 
+struct Scale {
+  const char* name;
+  const float frequencies[8];
+  int numNotes;
+};
+
+extern const Scale SCALES[];
+extern const int NUM_SCALES;
+extern volatile int currentScaleIndex;
+
 #endif // SHAREDSTATE_H

UIThread.cpp

@@ -14,13 +14,45 @@
 #define PIN_SDA 4
 #define PIN_SCL 5
 
+// Encoder Pins
+#define PIN_ENC_CLK 12
+#define PIN_ENC_DT  13
+
 Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
 
+volatile int8_t encoderDelta = 0;
+static uint8_t prevNextCode = 0;
+static uint16_t store = 0;
+
+// --- ENCODER INTERRUPT ---
+// Robust Rotary Encoder reading
+void readEncoder() {
+  static int8_t rot_enc_table[] = {0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0};
+
+  prevNextCode <<= 2;
+  if (digitalRead(PIN_ENC_DT)) prevNextCode |= 0x02;
+  if (digitalRead(PIN_ENC_CLK)) prevNextCode |= 0x01;
+  prevNextCode &= 0x0f;
+
+  // If valid state
+  if (rot_enc_table[prevNextCode]) {
+    store <<= 4;
+    store |= prevNextCode;
+    if ((store & 0xff) == 0x2b) encoderDelta--;
+    if ((store & 0xff) == 0x17) encoderDelta++;
+  }
+}
+
 void setupUI() {
   Wire.setSDA(PIN_SDA);
   Wire.setSCL(PIN_SCL);
   Wire.begin();
 
+  pinMode(PIN_ENC_CLK, INPUT_PULLUP);
+  pinMode(PIN_ENC_DT, INPUT_PULLUP);
+  attachInterrupt(digitalPinToInterrupt(PIN_ENC_CLK), readEncoder, CHANGE);
+  attachInterrupt(digitalPinToInterrupt(PIN_ENC_DT), readEncoder, CHANGE);
+
   if(!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
     Serial.println(F("SSD1306 allocation failed"));
     for(;;);
@@ -34,7 +66,36 @@ void setupUI() {
   display.display();
 }
 
-void loopUI() {
+void handleInput() {
-  // The loop on core 0 is responsible for updating the UI.
+  // Handle Encoder Rotation
-  delay(100);
+  int rotation = 0;
+  noInterrupts();
+  rotation = encoderDelta;
+  encoderDelta = 0;
+  interrupts();
+
+  if (rotation != 0) {
+    currentScaleIndex += rotation;
+    while (currentScaleIndex < 0) currentScaleIndex += NUM_SCALES;
+    while (currentScaleIndex >= NUM_SCALES) currentScaleIndex -= NUM_SCALES;
+  }
+}
+
+void loopUI() {
+  // sleep to avoid thread starvation
+  delay(10);
+
+  handleInput();
+  // The loop on core 0 is responsible for updating the UI.
+  static unsigned long lastUpdate = 0;
+  if (millis() - lastUpdate < 100) return;
+  lastUpdate = millis();
+
+  display.clearDisplay();
+  display.setCursor(0, 0);
+  display.setTextSize(1);
+  display.println(F("Current Scale:"));
+  display.setTextSize(2);
+  display.println(SCALES[currentScaleIndex].name);
+  display.display();
 }