The Knights of CANelot is a CAN-controlled power supply system board used
to control the power system for RIDER; starting the single board computer,
and more importantly its gracefully shutdown.
I self-designed the layout of the board myself, and had it sent out to a custom PCB fab shop to be manufactured. The board consists of a CAN BUS Controller and transceiver, microcontroller, and relay. The board constantly is monitoring the vehicle CAN network, waiting for any CAN communication to begin. Once the onboard CAN controller sees any network activity, the microcontroller is woken from it sleep state and triggers a relay to latch, providing power to the rest of the RIDER system.
The single board computer monitors the signal output from the Knights of CANelot, when the CAN network goes to sleep, i.e. when the car is turned off, the single board computer gracefully shuts down, and the microcontroller waits 20 seconds for the system to shutdown, then unlatches the relay.
The system draws minimal power in sleep mode, approximately 10 milliamps.