Arduino Mega2560 Manual page 31

4) Click Speed +/- button to accelerate or reduce speed
5) Rotate the mobile phone to change direction(steering wheel will rotate while you are
turning the phone).
6) Click Gear button to change gear to Forward or Backward direction.
7) Press F1 to Shift to left way, F5 to shift to right way, F3 to up left diagonal, F4 to
up right diagonal.
Youtube Video Link: https://youtu.be/GzVJng2rCBI