ECU master CAN switch board V3 A CAN switch board is a tiny device to allow easy transfer of up to 8 switch states and 8 analog signals over the CAN bus. In addition to this, the device has 4 built-in low side outputs that can be activated with a CAN bus message. The main purpose of this board is to build custom steering wheel panels containing buttons, rotary switches and indicators. The switchboard device is designed to work with EMU BLACK and PMU. It can also be used with any other devices with custom configurable CAN bus inputs.