SRF06 ultrasonic range finder

SRF06 ultrasonic range finder

I’ve played with an SRF06 range finder this week. The SRF06 is an ultrasonic distance measuring module. They are ideal to sense objects, so I bought 2 to put on the front and back of a robot. The Arduino library for these modules gives you the detected distance in centimeters or inches.

You can find the library and a basic sketch that sends the distance to the serial monitor here. These kind of sensors are used in cars to help drivers when parking.

So I started by making a basic sketch that would detect an object and would light a bunch of leds as the object comes closer just like the parking help I have in my car.

/*
  http://www.bajdi.com
  SRF06 module detecting distance in cm. The closer we get to the object
  the more leds start to burn.
  The circuit:
 * leds on pin 2,3,4,5
 * SRF06 module: trig to pin 12, echo to pin 13
*/

#include "Ultrasonic.h"

const int  TRIG = 9;
const int  ECHO = 10;
const int led1 = 2;
const int led2 = 3;
const int led3 = 4;
const int led4 = 5;
Ultrasonic SRF06(TRIG, ECHO);

void setup()
{
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(led4, OUTPUT);
}

void loop()
{
  if (SRF06.Ranging(CM) >= 100)
  {
    digitalWrite(led1, LOW);
    digitalWrite(led2, LOW);
    digitalWrite(led3, LOW);
    digitalWrite(led4, LOW);
  }
  if (SRF06.Ranging(CM) >= 80 && SRF06.Ranging(CM) < 100)   {     digitalWrite(led1, HIGH);     digitalWrite(led2, LOW);     digitalWrite(led3, LOW);     digitalWrite(led4, LOW);   }   if (SRF06.Ranging(CM) >= 60 && SRF06.Ranging(CM) < 80)   {     digitalWrite(led1, HIGH);     digitalWrite(led2, HIGH);     digitalWrite(led3, LOW);     digitalWrite(led4, LOW);   }   if (SRF06.Ranging(CM) >= 40 && SRF06.Ranging(CM) < 60)
  {
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    digitalWrite(led3, HIGH);
    digitalWrite(led4, LOW);
  }
  if (SRF06.Ranging(CM) < 40)
  {
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    digitalWrite(led3, HIGH);
    digitalWrite(led4, HIGH);
  }
}

I’ve looked around on the internet to find the datasheet for the SRF06 but haven’t been able to find it.  The SRF06 is an improved version of the SRF04, I wonder if they have the same specifications. Some info that I’ve found of the SRF06:

• power supply :5V
• DC quiescent current : less then 2mA
• effective angle: less then 15°
• ranging distance : 2cm – 500 cm
• resolution : 0.3 cm