User manual
  Picture connection as below: 
  Example code: 
  *********Code begin********* 
#define trigPin 13 
#define echoPin 12 
#define led 11 
#define led2 10 
void setup() { 
 Serial.begin (9600); 
 pinMode(trigPin, OUTPUT); 
 pinMode(echoPin, INPUT); 
 pinMode(led, OUTPUT); 
 pinMode(led2, OUTPUT); 
} 
void loop() { 
 long duration, distance; 
 digitalWrite(trigPin, LOW);  // Added this line 
 delayMicroseconds(2); // Added this line 
 digitalWrite(trigPin, HIGH); 
//  delayMicroseconds(1000); - Removed this line 
 delayMicroseconds(10); // Added this line 
 digitalWrite(trigPin, LOW); 
 duration = pulseIn(echoPin, HIGH); 
 distance = (duration/2) / 29.1; 
 if (distance < 4) {  // This is where the LED On/Off happens 
 digitalWrite(led,HIGH); // When the Red condition is met, the Green 
LED should turn off 



