HC-SR04 is an ultrasonic sensor which works on the principle of ultrasonic waves. Basically it creates a pulse depending on the distance from the sensor. It has two eyes like structure one of which transmits the waves and the other acts as receiver. The sensor has 4 pins VCC, TRIG, ECHO, GND. When the sensor is triggered by sending a pulse to TRIG pin, it sends a pulse through ECHO pin which can be measured.
1. Parts needed: Arduino, wires, Ultrasonic Sensor (HC-SR04).
2. Connections:
VCC pin to Arduino 5V
TRIG pin to Arduino pin 11
ECHO pin to Arduino pin 12
GND pin to Arduino GND
3. Code:
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void setup()
{ Serial.begin(9600); //Sensor TRIG pin to pin 11 pinMode(11, OUTPUT); //Sensor ECHO pin to pin 12 pinMode(12, INPUT); } void loop() { int duration, distance; //to send trigger pin to pin 11 by activating it for 50 microseconds digitalWrite(11, HIGH); delayMicroseconds(50); digitalWrite(11, LOW); //pulseIn function measures the time for which the pulse is high duration = pulseIn(12, HIGH); //conversion of time to distance distance = duration * 0.034 / 2; //prints the distance on serial monitor Serial.print(distance); Serial.print(” cm”); delay(100); } |
