//set the pin names
const int pingPin = 6;
const int echoPin = 9;
const int buzzer = 10;
const int button = 2;
int buttonState = 0;         // variable for reading the pushbutton status
bool Up = 0;
int pullUps = 0;
int distance = 50;
//convert to centimetres
long microsecondsToCentimeters(long microseconds) {
  return microseconds / 29 / 2;
}

void setup() {
  Serial.begin(9600);
  pinMode(pingPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(buzzer, OUTPUT);
  pinMode(button, INPUT);

}

void loop() {
  int state = 0;
  if (digitalRead(button) == HIGH && state == 0) {
    state = 1;

    while (state>0) {
      long duration, cm;
      //send and receive ultrasound to detect distance
      digitalWrite(pingPin, LOW);
      delayMicroseconds(2);
      digitalWrite(pingPin, HIGH);
      delayMicroseconds(10);
      digitalWrite(pingPin, LOW);
      pinMode(echoPin, INPUT);
      duration = pulseIn(echoPin, HIGH);
      cm = microsecondsToCentimeters(duration);
    
      //check if distance in centimetres is less than 50cm
      if (cm > distance  && Up) {
        Up = false;
      }
      
      else if(cm <= distance && !Up) {
        Up = true;
        pullUps++;
        digitalWrite(buzzer, HIGH);
        delay(50);
        digitalWrite(buzzer, LOW);
        delay(50);
        Serial.println(pullUps);
    
      }
      delay(300);
      if(digitalRead(button)==HIGH){
        state = 0;
        delay(200);
      }
    }
  }
  
    

}