Chassis
The CHASSIS expansion is used to simulate some functions usally found in the Chassis domain of a car:
Steering Wheel
Parking Brake
Although not traditionally part of the Chassis domain, the lighting switch is also present on the Chassis domain, out of convenience.
Steering Wheel
The Steering wheel is simulated by a rotating potentiometer. A TVS diode is used for ESD protection, and a capacitor also protects the ECU input from chattering.
Parking Brake
The parking brake is simulated by a pulled-up sliding switch. A TVS diode is used for ESD protection.
Lighting Switch
The lighting switch is simulated by a rotating switch from the NR01 series of NKK switches. A TVS diode is used for ESD protection. The rotation of the switch selects a point from a voltage divider , which is measured by an ADC on the ECU.