Not totally sure if this will work, so just brainstorming here.
The CAN bus transceiver receive pin going to the Teensy is always being driven either HIGH or LOW. If there is no CAN bus activity or it is disconnected, the output is driven LOW...
OK, but there is no way to make changes to hardware at this point. It's in production and in use. I have a firmware update that only canbus devices should get. Don't want to be doing two firmware and leaving it up to the client to decide.
Hey guys, I have a device with some menu items and one of them is a canbus menu.
I want only the devices that have the SN65H CAN chip to see that menu.
Is there any way I can code this?