Como Scannear dispositivos no barramento I2C - Arquivo 015

Referêcia:
http://www.arduinoecia.com.br/2015/04/arduino-lcd-16x2-modulo-i2c-rtc-ds1307.html

Lista de Materiais:
IDE Arduino 1.0.6
1x  Board Arduino UNO
1x  Protoboard 830 furos
1x  Cabo USB-A male to USB-B male 
1x  Conj. de fios jumper p/ protoboard
1x  Sensor de temperatura MLX90615
1x  C.I. DS1307 RTC
1x  Display I2C / Drive PCF8574AP

Montagem:
Esse programa varre o barramento I2C e mostra no serial monitor o endereço dos dispositivos conectados.

Firmware:
#include <Wire.h>
//****************************************************************************
void setup(){
  Wire.begin();
  Serial.begin(9600);
  Serial.println("\nI2C Scanner");
}
//****************************************************************************
void loop(){
  byte error, address;
  int nDevices;
  Serial.println("Scanning...");
  nDevices = 0;
  for(address = 1; address < 127; address++ ) {
    // The i2c_scanner uses the return value of
    // the Write.endTransmisstion to see if
    // a device did acknowledge to the address.
    Wire.beginTransmission(address);
    error = Wire.endTransmission();

    if (error == 0){
      Serial.print("I2C device found at address 0x");
      if (address<16) 
        Serial.print("0");
      Serial.print(address,HEX);
      Serial.println("  !");
      nDevices++;
    }
    else if (error==4) {
      Serial.print("Unknow error at address 0x");
      if (address<16) 
        Serial.print("0");
      Serial.println(address,HEX);
    }    
  }
  if (nDevices == 0)
    Serial.println("No I2C devices found\n");
  else
    Serial.println("done\n");
  delay(5000);         
}

Download: não necessário