This is where that extra circuit comes in: it changes the way a CAN bus operates so that other ECUs on that bus cannot talk. The gateway can still listen to messages, and can of course still send ...

It’s a small PCB with an onboard CAN interface from an ESP32-S3 and a car-friendly power supply circuit, and perhaps most importantly, it has an auto-shutdown feature to prevent battery drain.

Much of a vehicle’s CAN bus systems will be found hidden deep inside a car, but since modern headlights are so smart these days, they require their own ECUs, which means they’re going to be ...