Potential issue with new USB to CaN bridge?

Hi all, 1st post here, redirected from discord. Set up (on a bench with no steppers connected etc) a new printer configuration involving Octopus Pro, BTT EBB42 v1.0 toolboard connected via Octopus’ onboard RJ11 connector and new Klipper can-usb bridge feature. Everything seems to be working however when I issue firmware_restart (1st attached log) I’m getting ‘Failed automated reset of MCU ‘tool’’ error. Subsequent restart (2nd log) fixes that. Latest Klipper, bitrate for can is 250,000
klippy(mcu err).log (101.2 KB)
klippy(restart).log (210.0 KB)

Note that when I had txqueuelen set to 128 in /etc/network/interfaces.d/can0 even restart was not fixing the problem, I had to reboot the whole rig everyt time. with txqueuelen set to 1024 I got restart working, just not firmware_restart.

Given that can-usb bridge is very new is it a known issues or my setup error?


See Experimental "USB to CANbus bridge" mode - #37 by koconnor

As I noted in that thread, you can work around this by not making your bridge MCU the main MCU, and listing it last in your config.

Thanks a lot. That must be it - since it is a know issue and there is a chance it’ll be fixed in the future, I don;t mind hitting restart instead of firmware restart for some time. Thank you all.

FYI, the latest Klipper code now has improved reset ordering of FIRMWARE_RESTART commands for “bridge” mcus (commit 751bff7d). It does require upgrading and reflashing the mcu.


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Thanks a lot @koconnor !

Update: Upgraded klipper via update manager (it did not raise an error that mcu needed to be reflashed as I expected). Reflashed all mcu’s anyway and the issues is gone. Thanks!

Hello, for a some reason I still have a problem with FIRMWARE_RESTART in CAN bridge mode. Firmware version: v0.12.0-8, BTT Octopus plus Fly Mellow SB2040 CAN toolhead. MCU configuration as below. Please, could you check? BTW I use canboot mode in 2040 toolhead, could this have some influence?

canbus_uuid: 0692bed3a983

[mcu SB2040]
canbus_uuid: 40120b79508a

Please start a new thread, this one is 2 years old. Avoid necroing old threads in the future, you can just reference them as…

I have such and such issue as described here:


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