//warning on the volume of the sound T^T

int trigPin1 = 9; 
int echoPin1 = 10; 

const int buzzer1 = 7; 

long duration1, duration2;
int distance1, distance2;


void setup() {
  Serial.begin(9600);
  pinMode(trigPin1, OUTPUT);
  pinMode(echoPin1, INPUT);
  pinMode(buzzer1, OUTPUT);
}

void loop() {
  digitalWrite(trigPin1, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin1, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin1, LOW);
  duration1 = pulseIn(echoPin1, HIGH);
  distance1 = duration1 * 0.034 / 2;

  if (distance1 < 50) {
    tone(buzzer1, 1000);
  } else {
    noTone(buzzer1);
  }

  delay(50);
}