Issues setting up M2 on local dev CAN

Received an under-dash M2 last week ago or so. My first goal is to just sniff/verify traffic on a CAN project that’s on my desk – currently, it’s 3 nodes, 2 on arduino with CAN shields and one with 32M1 hosted on stk600 dev card. Communication/behavior of these nodes seems correct according to Serial messages, but I’d like to use M2 and SaavyCAN to see more, especially as project gets more complicated.

I followed instructions here ( to set M2 up for Win10 Saavy. So, after flashing M2Ret, i hooked up to my car and got reasonable CAN traffic. Good.

However, the instant I hook the M2 into my desktop CAN project, all traffic halts. Looking at the Atmega32M1 registers, it looks like there is a Form Error (FERR). I’ve hooked up the M2 referring to the pinout:

M2 pin 16 gets a solid 12vdc,
6 and 14 <–> CAN hi and low respectively
4 and 5 --> ground
All other pins are open.

Usb cable to M2 can be connected or not, no difference.

As soon as I unplug the M2, traffic goes back to normal with no Errors. It will run without errors indefinitely.

I’m I doing anything obviously noobish.


Nevermind ::slight_smile: In my case, I needed to go to SaavyCAN and connect device at correct Baud.

Great! Happy to hear you go things working.

It seems like Baud and termination are always the usual suspects…

Feel free to post up your project here and anything you learn.