Rotary encoder

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 handleInput() {
+  // Handle Encoder Rotation
+  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.
-  delay(100);
+  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();
 }