Making Things Talk

APPENDIX C 403

Chapter 8

Sharp GP2D12 IR ranger reader

Language: Wiring/Arduino

Reads the value from a Sharp GP2D12 IR ranger and sends

it out serially.

int sensorPin = 0; // Analog input pin

int sensorValue = 0; // value read from the pot

void setup() {

// initialize serial communications at 9600 bps:

Serial.begin(9600);

}

void loop() {

sensorValue = analogRead(sensorPin); // read the pot value

// the sensor actually gives results that aren't linear.

// this formula converts the results to a linear range.

if (sensorValue> 3) {

int range = (6787 / (sensorValue - 3)) - 4;

Serial.println(range, DEC); // print the sensor value

delay(10); // wait 10 milliseconds before the next loop

}

}

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()

{

Wire.begin(); // start the I2C bus.

// open the serial port:

Serial.beg