Hello, so I've had this 500kbps CAN network doing great for years, mainly using Devkit v1 ESP32's with MCP2551 and a 2.8" SPI TFT, with touch, etc. Working great. I probably have 3-4 of these, and they all work great reading CAN over GM OBD network, sending receiving, no problem. I chose the Devkit ...

Does anybody have anything? What I think is strange is, I can get the ESP32's that don't work on GM High Speed CAN to talk directly to each other as send/receive... but not on the GM High Speed Can network. My 6-7 original Devkit V1's work find though... just the newer ones don't work.

I wonder whether it's possible at all to use the standard CAN controller together with a single-wire CAN transceiver…

Not sure how to do that.. the ESP32 uses RX and TX to the external CAN transceiver.

I have also accessed the GM low speed bus.. .33.3kbps? I believe I did this with same library as you on ESP32, however my other main project uses the 500kbps CAN bus and I am having big problems finding ESP32 Devkit V1's that work... the older ones I have work fine but the newer ones.. only 1 out of ...