Arduino analog inputs all used apart from one for balancing etc.
All handcontroller inputs go in through the digital input pins on other side of the Arduino board.
The cable is fixed to the deck using simple cable ties again so the wires are not stressed where they are soldered to Arduino input pins. The cable itself is screened cable with 6 or more wires inside it.
You can also see the 10K potentiometer used to control the "overall gain" function. This allows simple user adjustment of the machine between feeling "squishy" and "tight" as you ride it.
NOTE: See my links on page 1 to my newer Instructables describing how to wire up newer IMU's to an Arduino and use it to control the skateboard, with code.
These newer versions do not use the potentiometer any more.