CAN0 and CAN1 sniffing at the same time using Macchina M2 does not work

Dear all,

I have a project on my BMW E90 and I need to sniff two individual CAN networks at the same time by using UTH Macchina M2 sniffer and Savvy CAN software. Unfortunately it does not work for some reasons.

I am able to sniff CAN0 via pins 19&20 without any problem, but when I try to sniff CAN1 via pins 7&8 it does not sniff any frames just silent.

Does anyone know what the problem could be? I assume that the problem is somehow is with GVRET sketch. My understanding is that the settings in GVRET Programm needs to be set in order to get both CAN channels to work.

Please help if someone know about this issue.

Make sure you can read the other canbus without issue on its own. It could (And likely is) a different speed. I would suggest only turning on the support for the second canbus while you are trying to get connected to it. Once you have figured that out you should then be able to run both canbus ports at the same time.

The point is that I cannot read “sniff” CAN1 on its own. i.e. CAN1 sniffing is not working while CAN0 is working with same speed setting when sniff one by one.
The CAN1 pin connection has been double checked for both Macchina M2 interfaces:

  • UTH: pin 7 (CAN1_Low) and pin 8 (CAN1_High)
  • UTD: pin 3 (CAN1_High) and pin 11 (CAN1_Low)

The problem has been resolved. I had to read this carefully:

https://docs.macchina.cc/projects/use-m2-with-savvycan

the key message is: `M2RET must be flashed to M2 to forward messages from the car to the computer and vice versa.

I must to use M2RET flash file for my Macchina M2 rather than to use GVRET program for sniffer purposes.

Once my M2 has been flashed with M2RET_Flash.bat it enabled the reading of CAN1 and CAN0 at the same time.

Best regards
Alex