Making Things Talk

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/*

SRF02 sensor reader

language: Wiring/Arduino

Reads data from a Devantech SRF02 ultrasonic sensor.

Should also work for the SRF08 and SRF10 sensors as well.

Sensor connections:

SDA - Analog pin 4

SCL - Analog pin 5

*/

// include Wire library to read and write I2C commands:

#include <Wire.h>

// the commands needed for the SRF sensors:

#define sensorAddress 0x70

#define readInches 0x50

// use these as alternatives if you want centimeters or microseconds:

#define readCentimeters 0x51

#define readMicroseconds 0x52

// this is the memory register in the sensor that contains the result:

#define resultRegister 0x02

void setup()

{

// start the I2C bus

Wire.begin();

// open the serial port:

Serial.begin(9600);

}

void loop()

{

// send the command to read the result in inches:

sendCommand(sensorAddress, readInches);

// wait at least 70 milliseconds for a result:

delay(70);

// set the register that you want to read the result from:

setRegister(sensorAddress, resultRegister);

// read the result:

int sensorReading = readData(sensorAddress, 2);

// print it:

Serial.print("distance: ");

Serial.print(sensorReading);

Serial.println(" inches");

// wait before next reading:

delay(70);

}

This sketch sends

commands to the SRF02

sensor to take distance readings and

return them to the microcontroller.

NOTE: If you have trouble ...