Intermittent CAN connectivity between ESP and STM

[sanielfishawy]

We are using the Model S front motor control board by Damian McGuire and the included ESP32 CAN Wifi board.

We notice intermittently when both boards are powered up the Web interface complains that the CAN connection is not working.

Is there a sequence these two boards need to be powered up in? Some other known problem?

[johu]

Yes there are some known issues which affect reliability on both the ESP and the STM side. But it mostly affects the initial download of the parameter list. So if I understand correctly the parameter list is there and you do get communication just not always? In that case I'd think it's the physical CAN connection because the value update itself isn't flawed by any of the known issues.

So check the usual suspects, termination and good connection.
Also check the value of resistor R6 on the ESP board - on early boards it was too high at 100k. Replace it by something lower or short it out alltogether

Hope that helps.