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root / arduino-1.0 / libraries / Wire / examples / SFRRanger_reader / SFRRanger_reader.ino @ 58d82c77

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// I2C SRF10 or SRF08 Devantech Ultrasonic Ranger Finder 
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// by Nicholas Zambetti <http://www.zambetti.com>
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// and James Tichenor <http://www.jamestichenor.net> 
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// Demonstrates use of the Wire library reading data from the 
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// Devantech Utrasonic Rangers SFR08 and SFR10
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// Created 29 April 2006
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// This example code is in the public domain.
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#include <Wire.h>
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void setup()
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{
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  Wire.begin();                // join i2c bus (address optional for master)
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  Serial.begin(9600);          // start serial communication at 9600bps
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}
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int reading = 0;
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void loop()
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{
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  // step 1: instruct sensor to read echoes
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  Wire.beginTransmission(112); // transmit to device #112 (0x70)
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                               // the address specified in the datasheet is 224 (0xE0)
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                               // but i2c adressing uses the high 7 bits so it's 112
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  Wire.write(byte(0x00));      // sets register pointer to the command register (0x00)  
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  Wire.write(byte(0x50));      // command sensor to measure in "inches" (0x50) 
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                               // use 0x51 for centimeters
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                               // use 0x52 for ping microseconds
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  Wire.endTransmission();      // stop transmitting
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  // step 2: wait for readings to happen
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  delay(70);                   // datasheet suggests at least 65 milliseconds
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  // step 3: instruct sensor to return a particular echo reading
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  Wire.beginTransmission(112); // transmit to device #112
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  Wire.write(byte(0x02));      // sets register pointer to echo #1 register (0x02)
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  Wire.endTransmission();      // stop transmitting
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  // step 4: request reading from sensor
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  Wire.requestFrom(112, 2);    // request 2 bytes from slave device #112
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  // step 5: receive reading from sensor
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  if(2 <= Wire.available())    // if two bytes were received
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  {
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    reading = Wire.read();  // receive high byte (overwrites previous reading)
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    reading = reading << 8;    // shift high byte to be high 8 bits
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    reading |= Wire.read(); // receive low byte as lower 8 bits
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    Serial.println(reading);   // print the reading
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  }
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  delay(250);                  // wait a bit since people have to read the output :)
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}
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/*
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// The following code changes the address of a Devantech Ultrasonic Range Finder (SRF10 or SRF08)
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// usage: changeAddress(0x70, 0xE6);
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void changeAddress(byte oldAddress, byte newAddress)
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{
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  Wire.beginTransmission(oldAddress);
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  Wire.write(byte(0x00));
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  Wire.write(byte(0xA0));
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  Wire.endTransmission();
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  Wire.beginTransmission(oldAddress);
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  Wire.write(byte(0x00));
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  Wire.write(byte(0xAA));
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  Wire.endTransmission();
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  Wire.beginTransmission(oldAddress);
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  Wire.write(byte(0x00));
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  Wire.write(byte(0xA5));
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  Wire.endTransmission();
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  Wire.beginTransmission(oldAddress);
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  Wire.write(byte(0x00));
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  Wire.write(newAddress);
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  Wire.endTransmission();
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}
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*/