int trig = 9; int echo = 7; int motor = 6; int a,distance; void setup() { Serial.begin(9600); pinMode(trig, OUTPUT); pinMode(motor, OUTPUT); pinMode(echo, INPUT); } void loop() { digitalWrite(trig, LOW); delayMicroseconds(5); digitalWrite(trig, HIGH); delayMicroseconds(10); digitalWrite(trig, LOW); a = pulseIn(echo, HIGH); distance= a*0.034/2; Serial.println(distance); if (distance <30) { digitalWrite(motor, HIGH); delay(1000); digitalWrite(motor, LOW); delay(3000); } else { digitalWrite(motor,LOW); } }