const int button_pin = 10;
const int led_pin = 6;
int button_value, old_button_value;
int counter;

void setup() {
  pinMode(button_pin, INPUT_PULLUP);
  pinMode(led_pin, OUTPUT);

  Serial.begin(9600);



}

void loop() {
  readButton();

  if(counter%2 == 1){
    digitalWrite(led_pin, HIGH);
  }
  else{
    digitalWrite(led_pin, LOW);
  }
}
  

void readButton(){
button_value = !digitalRead(button_pin);

if(button_value == 0 && old_button_value == 1){
  counter ++;
  Serial.println(counter);

}
else {
  delay(50);
}
  old_button_value = button_value;
}