This is my first time using Savvy CAN…wow is it an awesome piece of software. Excellent work to all who were involved in making it!
Unfortunately the one huge downside is that it doesnt support the third SWCAN bus on the M2.
But for anyone with a GM vehicle that wants to log both high speed GMLAN (500k) and low speed GMLAN (33k SWCAN) simultaneously…here is a quick and dirty hack:
Basically what you’re going to be doing is using the M2’s “MSCAN” port as SWCAN. Yes, MSCAN is dual-wire and SWCAN is, well, single wire. But all you have to do is tie the “MSCAN -” wire to ground, and the “MSCAN +” wire to the SWCAN pin on the OBD port (pin 1). And set the baud rate for “CAN1” to 33333 of course.
I made a little plug and play OBD port adapter for the M2 that does this “re-wiring” of the MSCAN +/- ports to the SWCAN pin and ground, respectively.
Is it “proper” to interface with a SWCAN bus this way? No, and Im sure Ill have the electrical engineers coming after me with pitchforks for doing this. But whatever, for tinkering around, it works perfectly fine.
Hopefully the Savvy CAN crew adds true SWCAN support using the M2’s MCP2515/TH8056 soon…but until then, heres something to get the GM guys up and running on both busses.