I need to interface with a device that talks UART, but with CAN bus signalling. Here's a picture where a tester (which I want to replicate) talked to that device:
While RS485 seems similar, the device doesn't want to recognize it, so I need to convert the behavior.
What kind of circuitry would be the best way to approach this? Is there something existing?
Normally you would just use a CAN PHY.
The problem is, if what you say about the logic levels is true, it for some weird reason is contrary to the usual logic levels, where the idle state of CANH == CANL == 2.5V is logic 1, and UART also idles at logic 1.
If you are sure, you need to invert the UART output to CAN PHY input.
It might be possible to use RS485 PHY to interface with the device, but then you need to control the driver enable with the UART data to simulate CAN bus.
Obvious to say, your buses need to be terminated with proper termination resistors and use a common ground reference between the devices for it to work.
