#define HEARTBEAT_LED  LED_BUILTIN   // GP25
#define BLINK_LED      15            // LED
#define BUTTON_PIN     2             // Push-button
#define POT_PIN        26            // ADC0


const unsigned long HEARTBEAT_INTERVAL = 500;   

bool blinkEnabled  = false;  // Toggled by button
bool blinkLedState = false;


bool lastButtonReading     = HIGH;// Button debounce
bool lastStableButtonState = HIGH;
unsigned long lastDebounceTime = 0;
const unsigned long DEBOUNCE_TIME = 30;


unsigned long lastHeartbeatTime = 0;
unsigned long lastBlinkTime     = 0;


bool heartbeatState = false;// Current heartbeat state


unsigned long lastPrintTime = 0;
const unsigned long PRINT_INTERVAL = 200;

void setup() {
  pinMode(HEARTBEAT_LED, OUTPUT);
  pinMode(BLINK_LED, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  pinMode(POT_PIN, INPUT);

  digitalWrite(HEARTBEAT_LED, LOW);
  digitalWrite(BLINK_LED, LOW);


  Serial1.begin(115200);
  Serial1.println("Pico blink + heartbeat + POT speed control started");
}

void loop() {
  unsigned long now = millis();


  if (now - lastHeartbeatTime >= HEARTBEAT_INTERVAL) {
    lastHeartbeatTime = now;
    heartbeatState = !heartbeatState;
    digitalWrite(HEARTBEAT_LED, heartbeatState ? HIGH : LOW);
  }


  handleButton(now);


  int potRaw = analogRead(POT_PIN);       // 0–4095
  unsigned long blinkInterval = map(potRaw, 0, 4095, 50, 1000);


  if (blinkEnabled) {
    if (now - lastBlinkTime >= blinkInterval) {
      lastBlinkTime = now;
      blinkLedState = !blinkLedState;
      digitalWrite(BLINK_LED, blinkLedState ? HIGH : LOW);
    }
  } else {
    digitalWrite(BLINK_LED, LOW);
    blinkLedState = false;
  }


  if (now - lastPrintTime >= PRINT_INTERVAL) {
    lastPrintTime = now;

    Serial1.print("Button: ");
    Serial1.print(blinkEnabled ? "ON" : "OFF");
    Serial1.print(" | POT raw: ");
    Serial1.print(potRaw);
    Serial1.print(" | Blink interval (ms): ");
    Serial1.print(blinkInterval);
    Serial1.print(" | LED state: ");
    Serial1.println(blinkLedState ? "HIGH" : "LOW");
  }
}


void handleButton(unsigned long now) {              // debounce
  bool reading = digitalRead(BUTTON_PIN);

  if (reading != lastButtonReading) {
    lastDebounceTime = now;
    lastButtonReading = reading;
  }

  if ((now - lastDebounceTime) > DEBOUNCE_TIME) {
    if (reading != lastStableButtonState) {
      lastStableButtonState = reading;
      if (lastStableButtonState == LOW) {
        blinkEnabled = !blinkEnabled;
        Serial1.print("Button pressed -> Blink ");
        Serial1.println(blinkEnabled ? "ENABLED" : "DISABLED");
      }
    }
  }
}