arduino ultrasonic sensor project

       Arduino ultrasonic sensor project 

the circuit is follow

in this project we program for when the distance <100cm the led is on 

and else led is off 

in this project we need 

• arduino board
• ultrasonic sensor
• led 

in this project the distance can show on the serial monitor 

the code is follow 

#include <Ultrasonic.h>

#define TRIGGER_PIN  12

#define ECHO_PIN     13

int ledPin =10;

Ultrasonic ultrasonic(TRIGGER_PIN, ECHO_PIN);

void setup()

  {

    pinMode(ledPin,OUTPUT);

  Serial.begin(9600);

  }

void loop()

  {

  float cmMsec, inMsec;

  long microsec = ultrasonic.timing();

  cmMsec = ultrasonic.convert(microsec, Ultrasonic::CM);

  inMsec = ultrasonic.convert(microsec, Ultrasonic::IN);

  Serial.print("MS: ");

  Serial.print(microsec);

  Serial.print(", CM: ");

  Serial.print(cmMsec);

  Serial.print(", IN: ");

  Serial.println(inMsec);

  delay(100);

  if(cmMsec<100){

    digitalWrite(ledPin,HIGH);

  }else 

   digitalWrite(ledPin,LOW);

  }

the library file is here https://www.dropbox.com/s/8edr0zga6j3lf09/HCSR04Ultrasonic.rar?dl=0

if you want to change your distance like this

  if(cmMsec<100){

    digitalWrite(ledPin,HIGH);

  }else 

   digitalWrite(ledPin,LOW);

  }