#define PIN_TRIG 5
#define PIN_ECHO 6
#define led1 12

void setup() {
  Serial.begin(115200);
  pinMode(PIN_TRIG, OUTPUT);
  pinMode(PIN_ECHO, INPUT);
pinMode(led1, OUTPUT);
}

void loop() {
  // Start a new measurement:
  digitalWrite(PIN_TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(PIN_TRIG, LOW);

  // Read the result:
  int duration = pulseIn(PIN_ECHO, HIGH);
  Serial.print("Distance in CM: ");
  Serial.println(duration / 58);
  Serial.print("Distance in inches: ");
  Serial.println(duration / 148);

if (duration/58 < 40){
  digitalWrite(led1, HIGH);
} else {
  digitalWrite(led1, LOW);
}
  
  delay(1000);
}