Analyze CAN bus signals

[praveenvsn]

Hi,

I am trying to debug an issue with a CAN Transceiver where in, the MCU is sending the data to MCP2515 via SPI, but the receiving end is not seeing any message.

I would like to check if the signals are going through on the CANH and CANL lines.

1. Is it possible to connect CAN lines to the Logic Analyzer?
2. If yes, then which pins on the Rpi Pico can I use?

[gusmanb]

I have never tested it, but in theory you should be able to directly see CANL channel on high-speed or CANH in low speed according to these specs:

The PICO GPIOs count as low anything below 1.8v, so it matches CANH for low speed and CANL for high speed. Beware not mixing these as CANL in low speeds can get up to 5V (if you have a PICO with the RP2350 A4 it should be tolerant but I'm not responsible if it gets fried... xD) and CANH does not swing enough to be read.

To connect it check the Wiki section about barebones configuration.