 * - http://stackoverflow.com/questions/21073085/how-to-send-4-pot-values-via-i2c-from-arduino-to-arduino-how-to-differentiate-t
 * About SD Cards:
 * - https://learn.adafruit.com/adafruit-micro-sd-breakout-board-card-tutorial/format
-* Some useful information about Aprilia RSV/SL bikes work: (See: http://www.aprilia-v60.com/index.php?topic=262315)
+* About MPU6050:
+* - http://playground.arduino.cc/Main/MPU-6050
+* - https://github.com/jrowberg/i2cdevlib/tree/master/Arduino/MPU6050
+* - http://www.geekmomprojects.com/mpu-6050-redux-dmp-data-fusion-vs-complementary-filter/
+* Some useful information about Aprilia RSV/SL 1000 bikes work: (See: http://www.aprilia-v60.com/index.php?topic=262315)
 * - Speed sensor: purple/green wire=Vcc ~ 9V ? / grey/white: signal ~6.5V, falling to 0V
 * - Engine pulses/revolution: 3 if read from the dashboard wire
 * - Engine pulses/revolution: 6 if crank shaft sensor is used


unsigned long lastmillis;

File file;


uint8_t i2c_values[6];


  // or the SD library functions will not work. 
  pinMode(10, OUTPUT);

  if (!SD.begin(chipSelect)) {
    Serial.println("Initialization failed! ");
    return;
  }
  Serial.println("initialization done.");

  // I2C Slave configuration
  Wire.begin(I2C_ADDRESS);                // join i2c bus with address #4
