#include <Servo.h>

Servo myservo;  // create servo object to control a servo

// Constants for pin assignments
const int buttonPin1 = 2; // pin connected to the left-turn button
const int buttonPin2 = 3; // pin connected to the right-turn button
const int ledPin = 13;    // pin connected to the LED
const int servoPin = 9;   // pin connected to the Servo

// Function prototypes
void turnLeft();
void turnRight();

// Variables to store the servo position and the last debounce times
int servoPos = 90;        // start at mid-point, 90 degrees
unsigned long lastDebounceTime1 = 0;  // last debounce time for button 1
unsigned long lastDebounceTime2 = 0;  // last debounce time for button 2
unsigned long debounceDelay = 50;     // the debounce time in milliseconds

void setup() {
  myservo.attach(servoPin);           // attaches the servo on the specified pin to the servo object
  pinMode(ledPin, OUTPUT);            // sets the LED pin as output
  pinMode(buttonPin1, INPUT_PULLUP);  // sets the left-turn button pin as input with internal pull-up
  pinMode(buttonPin2, INPUT_PULLUP);  // sets the right-turn button pin as input with internal pull-up

  myservo.write(servoPos);            // centers the servo
  digitalWrite(ledPin, LOW);          // ensures the LED is off to start

  // Set up interrupts for button presses
  attachInterrupt(digitalPinToInterrupt(2), turnLeft, FALLING);
  attachInterrupt(digitalPinToInterrupt(3), turnRight, FALLING);
}

void loop() {
  // Nothing to do here
}

void turnLeft() {
  if ((millis() - lastDebounceTime1) > debounceDelay) {
    if (servoPos >= 10) {  // Check if the position is greater than or equal to 10
      servoPos -= 10;      // Decreases the position by 10 degrees
      myservo.write(servoPos);  // Move servo to new position
      lastDebounceTime1 = millis();
    }
    updateLED();  // Update the LED status based on new position
  }
}

void turnRight() {
  if ((millis() - lastDebounceTime2) > debounceDelay) {
    if (servoPos <= 170) {  // Check if the position is less than or equal to 170
      servoPos += 10;       // Increases the position by 10 degrees
      myservo.write(servoPos);  // Move servo to new position
      lastDebounceTime2 = millis();
    }
    updateLED();  // Update the LED status based on new position
  }
}

void updateLED() {
  // Turn on the LED if the servo is at 0 or 180 degrees, otherwise turn it off
  if (servoPos == 0 || servoPos == 180) {
    digitalWrite(ledPin, HIGH);
  } else {
    digitalWrite(ledPin, LOW);
  }
}