MCU randomly disconnect

General Discussion
1

Basic Information:

Screenshot 2025-07-22 192840
Screenshot 2025-07-22 1928401146×725 48.8 KB

Printer Model: Voron2.4
MCU / Printerboard: Octopus 1.1
Host / SBC BTT Pi 1.2
klippy.log
klippy.log (2.7 MB)

Full log. 40mb.
klippy.zip (3.2 MB)

Fill out above information and in all cases attach your klippy.log file (use zip to compress it, if too big). Pasting your printer.cfg is not needed
Be sure to check our “Knowledge Base” Category first. Most relevant items, e.g. error messages, are covered there

Describe your issue:

Printer randomly disconnect. Already tried multiple USB cables. BTT’s, short blue shielded cable for ESP32 flashing, and OEM phone data cable. Use contact cleaner to clean surface contact. BTT Octopus(mcu) use klipper fw and toolhead mcu use katapult.

2

Your log does not seem to contain any relevant shutdown events.
What is the error message in the webinterface? Please provide a log showing the issue.

3
  1. It just show MCU disconnect without any explanation.
  2. How do I know which file and which line show error?
4

Reproduce the issue and take a screenshot, please. Also attach the klippy.log directly after the event.

5

Screenshot 2025-07-22 192840
Screenshot 2025-07-22 1928401146×725 48.8 KB

The file is too large to upload on this site so…

moonraker.log (179.3 KB)

6

Please upload your logs here - not to (another) file server.
If the log is too long, you can zip to compress it.

7

klippy.zip (3.2 MB)

8

From the log, it seems that the Klippy-host on your BTT Pi is spontaneously restarting. This, in turn, leads to an MCU shutdown and is the consequence of the error you also see on your screenshot – the MCU needs a reset to clear its error condition.

  • Make sure you are not doing something to initiate it.
  • Check system logs on the BTT for traces that might provide a clue.
9

It look like this.

biqu@VORON-V2:~$ journalctl -u klipper.service -n 20
Jul 22 03:17:18 VORON-V2 systemd[1]: Started klipper.service - Klipper 3D Printer Firmware SV1.
Jul 22 11:59:43 VORON-V2 systemd[1]: klipper.service: Main process exited, code=killed, status=11/SEGV
Jul 22 11:59:43 VORON-V2 systemd[1]: klipper.service: Failed with result 'signal'.
Jul 22 11:59:43 VORON-V2 systemd[1]: klipper.service: Consumed 34min 28.430s CPU time.
Jul 22 11:59:53 VORON-V2 systemd[1]: klipper.service: Scheduled restart job, restart counter is at 1.
Jul 22 11:59:53 VORON-V2 systemd[1]: Stopped klipper.service - Klipper 3D Printer Firmware SV1.
Jul 22 11:59:53 VORON-V2 systemd[1]: klipper.service: Consumed 34min 28.430s CPU time.
Jul 22 11:59:53 VORON-V2 systemd[1]: Started klipper.service - Klipper 3D Printer Firmware SV1.
10

This is, unfortunately, an unfavorable result for multiple reasons:

  • It appears to be a segmentation fault of the host process.
  • It does not seem to contain any stack traces → manually scrutinize your logs for more information, e.g. syslog, kern.log (check what is available) etc.
  • You are using a modified Klipper version, so it is unclear if this is a Klipper inherent problem or caused by the modifications → make sure to use the latest cartographer code and firmware.
11

That’s a very very huge klippy.log MCU randomly disconnect - #7 by erk :wink:

My first impression is, you run a very hot system.

temp_sineos_2
temp_sineos_22414×1125 277 KB

MCU-TOOLHEAD: (I guess an EBB) up to almost 90°C! That is amazing. Or I made a mistake!
LINUX-HOST: BTT Pi 1.2 up to almost 66°C. That’s very hot.
MCU-MAIN: Octopus 1.1 over 50°C. I think, that’s ok.

I hope my interpretation is right!

Where did you mount your BTT Pi 1.2? Close to the chamber? How do you cool it?

You should get rid of that.

12
  • I will try looking into the system log.
  • For now I change Niceness of klipper.service to -10.
  • Cartographer is not in used. I burned it out when I try disassembly the toolhead without power down and now using klicky.
13
14

These are very likely problems that could have been solved quite easily.

This is good, as it takes out the need for modification.

I propose the following course of action:

  1. Backup your Klipper configuration files.
  2. Use a new SD card of good quality to exclude errors coming from it.
  3. Flash either the Armbian CB1 server image or the latest BTT image to the card. I strongly recommend trying the Armbian one first.
  4. Run sudo apt update && sudo apt full-upgrade, reboot, and check the board is generally working.
  5. Use the latest KIAUH to install everything. Choose xorg if asked.
  6. Build and flash new Klipper firmwares for the board and EBB
  7. Remove the cartographer from the printer.cfg.
  8. Put back your configuration files.
  9. Reboot and check if everything comes up properly.

Hardware-wise make sure that you have oriented your fans such that you secure an airflow in the shown direction:

grafik
grafik974×734 128 KB

15

armbian problem:
After first time setup wizard reboot to the non-root user. Lost access to wireless network entirely. Tried on multiple sd card to no avail.

16

This is normal for modern Linux distributions, and it is done intentionally. Work with sudo or research how to activate direct root access (not recommended).

Try to activate the wireless connection with sudo armbian-config

17

Mmmmh, very hot system.
I wonder why your MCU-TOOLHEAD is still working. The temperature is WAY too high.

You could turn the BTT Pi 1.2 90° CCW. You got enough space. I think this would improve the cooling. Also don’t place the USB cable above (or under, depends on the perspective) the heatsink. This also reduces the cooling a tiny bit and you are struggling with every degree :wink:

suggestion
suggestion999×750 291 KB

18

Update:

2025-07-25T13:00:44.231357+00:00 VORON-V2 KlipperScreen-start.sh[2145]: 20250725 13:00:44,229 [job_status.py:update_filename] - Updating filename to temperature_tower_ASA_1h3m.gcode
2025-07-25T13:00:44.232365+00:00 VORON-V2 KlipperScreen-start.sh[2145]: 20250725 13:00:44,229 [job_status.py:_update_file_metadata] - Update Metadata. File: temperature_tower_ASA_1h3m.gcode Size: 4023469
2025-07-25T13:01:33.126857+00:00 VORON-V2 systemd[1]: klipper.service: Main process exited, code=killed, status=7/BUS
2025-07-25T13:01:33.127647+00:00 VORON-V2 systemd[1]: klipper.service: Failed with result 'signal'.
2025-07-25T13:01:33.131062+00:00 VORON-V2 systemd[1]: klipper.service: Consumed 19.825s CPU time.
2025-07-25T13:01:33.161679+00:00 VORON-V2 KlipperScreen-start.sh[2145]: 20250725 13:01:33,158 [printer.py:change_state] - Changing state from 'printing' to 'disconnected'

I can’t config wireless in armbian-config as it cannot find a single SSID when I run search. Other method like adding a config file also not work.

As it is, I can’t get it to stop randomly restart no matter what.

I am buying a Pi now. Likely keep btt as a component tester board as it’s too unreliable for real work in its current state.