#define BUTTON_PIN 2
#define LED_PIN 4

//led blinking lgoic
unsigned long LastBlink=0;
const unsigned long interval=500;
int lastState=LOW;
bool ledblinkstate=true;

//debounce state
unsigned long lastdebounce = 0;
unsigned long debouncedelay = 50;
int buttonstate = HIGH;
int lastButtonReading = HIGH;

void setup()
{
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
}

void loop()
{
  unsigned long now=millis();
  // Button debounce check + BUTTON CHECK//
  int reading = digitalRead(BUTTON_PIN);
  if(reading != lastButtonReading)
  {
    lastdebounce = now;
  }
  if(now-lastdebounce > debouncedelay)
  {
    if(reading != buttonstate)
    {
      buttonstate = reading;
      if(buttonstate == LOW)
      {
        ledblinkstate = false;
        digitalWrite(LED_PIN, LOW);
      }
      else
      {
        ledblinkstate = true;
      }
    }
  }
  lastButtonReading = reading;

  //led on state se blinking state mein convert karna
  
    if(ledblinkstate)
    {
      if((now-LastBlink) >= interval)
      {
        LastBlink = now;
        lastState =! lastState;
        digitalWrite(LED_PIN, lastState);
      }
    }
}