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