int trigPin=4;
int echoPin=5;
int led=13;
int led1=12;
void setup(){
Serial.begin (9600);
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
pinMode(led, OUTPUT);
pinMode(led1, OUTPUT);
}
void loop(){
long duration, distance;
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
duration = pulseIn(echoPin, HIGH);
distance = (duration/2) / 29.1;
if (distance < 20){
digitalWrite(led,HIGH);
digitalWrite(led1,HIGH);
}
else{
digitalWrite(led,LOW);
digitalWrite(led1,LOW);
}
Serial.print(distance);
delay(500);
}