// === PIN DEFINITIONS ===
int CLK = 4;        // Clock pin of rotary encoder
int DT = 5;         // Data pin of rotary encoder
int SW = 6;         // Pushbutton (optional)

int LED_PIN = 13;   // Built-in LED for feedback

// === STATE VARIABLES ===
int lastCLK = HIGH;       // Previous state of CLK
int currentCLK;
int currentDT;

unsigned long lastDebounceTime = 0;
const int debounceDelay = 10;  // milliseconds

void setup() {
  // Initialize pins
  pinMode(CLK, INPUT_PULLUP);
  pinMode(DT, INPUT_PULLUP);
  pinMode(SW, INPUT_PULLUP);
  pinMode(LED_PIN, OUTPUT);

  // Start serial communication
  Serial.begin(9600);
  while (!Serial); // Wait for serial monitor (useful for Nano with CH340)

  // Initial read
  lastCLK = digitalRead(CLK);

  // Let user know we started
  Serial.println("🟢 Rotary Encoder Debug Mode");
  Serial.println("Rotate the knob and watch for output...");
  Serial.println("Format: [CLK | DT] → Direction");
}
  
void loop() {
  unsigned long currentTime = millis();

  // Debounce delay - poll every 10ms
  if (currentTime - lastDebounceTime < debounceDelay) {
    return;
  }
  lastDebounceTime = currentTime;

  // Read both pins
  currentCLK = digitalRead(CLK);
  currentDT  = digitalRead(DT);

  // Detect rising or falling edge on CLK
  if (currentCLK != lastCLK) {
    
    // Small extra delay for stability (simulate hysteresis)
    delayMicroseconds(500);  // Half a millisecond stabilizes contact

    int stableCLK = digitalRead(CLK);
    int stableDT  = digitalRead(DT);

    // Re-check after stabilization
    if (stableCLK == currentCLK) {  // Confirmed change
      if (stableCLK != lastCLK) {

        // Determine direction based on DT relative to CLK
        if (stableDT != stableCLK) {
          Serial.println("[↗️  CW] Clockwise Rotation Detected!");
          digitalWrite(LED_PIN, !digitalRead(LED_PIN));  // Toggle LED
        } else {
          Serial.println("[↙️  CCW] Counterclockwise Rotation Detected!");
          digitalWrite(LED_PIN, !digitalRead(LED_PIN));  // Toggle LED
        }

        // Optional: show raw values
        Serial.print("   CLK=");
        Serial.print(stableCLK);
        Serial.print(" DT=");
        Serial.println(stableDT);
      }
    }

    // Update last state
    lastCLK = stableCLK;
  }

  // Optionally check switch press
  if (digitalRead(SW) == LOW) {
    Serial.println("🔘 PUSH BUTTON PRESSED!");
    delay(300); // Simple debounce
  }
}