twinkle_bike.ino

const unsigned int leftLED = 3; // LED on left side
const unsigned int leftButton = 2; // Button on left side
const unsigned int rightLED = 10; // LED on right side
const unsigned int rightButton = 11; // Button on right side

int ledState = LOW;
int buttonState;
int previousState = HIGH;

long lastDebounceTime = 0;
long debounceDelay = 50;

int flashState = LOW;
unsigned long previousMillis = 0;


void setup() {
  pinMode(leftLED, OUTPUT);
  pinMode(leftButton, INPUT);
  pinMode(rightLED, OUTPUT);
  pinMode(rightButton, INPUT);
  Serial.begin(9600);
}

void loop() {
  int leftValue = debounce(leftButton);
  int rightValue = debounce(rightButton);

  if (leftValue == HIGH)
    flash(leftLED);
  else
    digitalWrite(leftLED, LOW);
  if (rightValue == HIGH)
    flash(rightLED);
 
}

int debounce(int currentButton) {
  int reading = digitalRead(currentButton);

  if (reading != previousState)
    lastDebounceTime = millis();

  if (millis() - lastDebounceTime > debounceDelay) {
    if (reading != buttonState) {
      buttonState = reading;

      if (buttonState == HIGH) {
        ledState = !ledState;
      }
    }
  }

  previousState = reading;
  Serial.println(ledState);
  return ledState;
}

void flash(int side) {
  unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >= 300) {
    previousMillis = currentMillis;
    flashState = (flashState == LOW) ? HIGH : LOW;
    digitalWrite(side, flashState);
  }

}