/*************************** I2C scan function **********************************/
#ifdef SERIAL_DEBUG
void I2Cscan()
{
  // scan for i2c devices
  byte error, address;
  int nDevices;

  Serial.println(F("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(F("I2C device found at address 0x"));
      if (address < 16)
        Serial.print(F("0"));
      Serial.print(address, HEX);
      Serial.println(F("  !"));

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

}
#endif