Scan.h

void ScanI2c(){
    byte error, address;
    int nDevices;
    Serial.println("Scanning...");
    nDevices = 0;
    for(address = 1; address < 127; 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.println(address,HEX);
        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");
    }
}