const int pinTrig = A1;
const int pinEcho = A0;
const int pinButton = A2;

void setup() {
  Serial.begin(115200);
  pinMode(pinTrig, OUTPUT);
  pinMode(pinEcho, INPUT);
  pinMode(pinButton, INPUT); 
}

void loop() {
  if (digitalRead(pinButton) == HIGH ) {
    digitalWrite(pinTrig, HIGH);
    delayMicroseconds(10);
    digitalWrite(pinTrig, LOW);
    int duration = pulseIn(pinEcho, HIGH);
    Serial.print("Distance in CM: ");
    Serial.println(duration / 58.0);
    delay(1000);
    
  }

  
}
....