Robot Car part 1 Distance sensor

Wiring

HC-SR04  to Arduino Nano

Vcc  >>  5 Vcc

Trig  >>  D13

Echo >>  D12

Gnd  >>  Gnd

Code:  

const int pingPin = 13;

int inPin = 12;

void setup() {

Serial.begin(9600);

}

void loop()

{

long duration, cm;

pinMode(pingPin, OUTPUT);

digitalWrite(pingPin, LOW);

delayMicroseconds(2);

digitalWrite(pingPin, HIGH);

delayMicroseconds(5);

digitalWrite(pingPin, LOW);

pinMode(inPin, INPUT);

duration = pulseIn(inPin, HIGH);

cm = microsecondsToCentimeters(duration);

Serial.print(cm);

Serial.print("cm");

Serial.println();

delay(100);

}

long microsecondsToCentimeters(long microseconds)

{

// The speed of sound is 340 m/s or 29 microseconds per centimeter.

// The ping travels out and back, so to find the distance of the

// object we take half of the distance travelled.

return microseconds / 29 / 2;

}