Introduction: Arduino Ultrasonic Sensor
this is example to use ultrasonic sensor( HC-SR04 ) in arduino.
Step 1: Part List :
- Arduino UNO R3 Board
- HC-SR04 Ultrasonic Sensor
- Red LED
- Green LED
- 560 ohm (Green, Blue, Brown, Gold) Resistors
- HalfBreadboard
- wires
Step 2: Connect the Components
Step 3: Write Your Code
#define trigPin 13
#define echoPin 12
#define greenLED 11
#define redLED 10
void setup() {
Serial.begin (9600);
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
pinMode(greenLED, OUTPUT);
pinMode(redLED, 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 < 4) { // This is where the LED On/Off happens
digitalWrite(greenLED,HIGH); // When the Red condition is met, the Green LED should turn off digitalWrite(redLED,LOW);
} else {
digitalWrite(greenLED,LOW); digitalWrite(redLED,HIGH);
}
if (distance >= 200 || distance <= 0){
Serial.println("Out of range");
} else {
Serial.print(distance); Serial.println(" cm");
} delay(500);
}