Lost communication with MCU 'mcu' - CAN bus?

General Discussion
1

Basic Information:

Printer Model: Homemade
MCU / Printerboard: MANTA + CB1
Host / SBC
klippy.log

Describe your issue:

Hi, sometimes the printer stops printing for no reason. Could this be caused by CAN bus communication?

latest error message in klippy.log:

Lost communication with MCU 'mcu'
Once the underlying issue is corrected, use the
"FIRMWARE_RESTART" command to reset the firmware, reload the
config, and restart the host software.
Printer is shutdown

Script running error
Traceback (most recent call last):
  File "/home/biqu/klipper/klippy/extras/filament_switch_sensor.py", line 58, in _exec_gcode
    self.gcode.run_script(prefix + template.render() + "\nM400")
  File "/home/biqu/klipper/klippy/gcode.py", line 229, in run_script
    self._process_commands(script.split('\n'), need_ack=False)
  File "/home/biqu/klipper/klippy/gcode.py", line 211, in _process_commands
    handler(gcmd)
  File "/home/biqu/klipper/klippy/gcode.py", line 137, in <lambda>
    func = lambda params: origfunc(self._get_extended_params(params))
  File "/home/biqu/klipper/klippy/extras/gcode_macro.py", line 189, in cmd
    self.template.run_gcode_from_command(kwparams)
  File "/home/biqu/klipper/klippy/extras/gcode_macro.py", line 68, in run_gcode_from_command
    self.gcode.run_script_from_command(self.render(context))
  File "/home/biqu/klipper/klippy/gcode.py", line 226, in run_script_from_command
    self._process_commands(script.split('\n'), need_ack=False)
  File "/home/biqu/klipper/klippy/gcode.py", line 211, in _process_commands
    handler(gcmd)
  File "/home/biqu/klipper/klippy/gcode.py", line 137, in <lambda>
    func = lambda params: origfunc(self._get_extended_params(params))
  File "/home/biqu/klipper/klippy/extras/gcode_macro.py", line 189, in cmd
    self.template.run_gcode_from_command(kwparams)
  File "/home/biqu/klipper/klippy/extras/gcode_macro.py", line 68, in run_gcode_from_command
    self.gcode.run_script_from_command(self.render(context))
  File "/home/biqu/klipper/klippy/gcode.py", line 226, in run_script_from_command
    self._process_commands(script.split('\n'), need_ack=False)
  File "/home/biqu/klipper/klippy/gcode.py", line 211, in _process_commands
    handler(gcmd)
  File "/home/biqu/klipper/klippy/gcode.py", line 285, in cmd_default
    raise gcmd.error(self.printer.get_state_message()[0])
gcode.CommandError: Lost communication with MCU 'mcu'
Once the underlying issue is corrected, use the
"FIRMWARE_RESTART" command to reset the firmware, reload the
config, and restart the host software.
Printer is shutdown

Lost communication with MCU 'mcu'
Once the underlying issue is corrected, use the
"FIRMWARE_RESTART" command to reset the firmware, reload the
config, and restart the host software.
Printer is shutdown

klippy (1).log (3.3 MB)

2

Check your log some lines up the error message:

b'Got error -1 in can read: (100)Network is down'
b'Got error -1 in can read: (100)Network is down'
Stats 4019.8: gcodein=0  mcu: mcu_awake=0.120 mcu_task_avg=0.000022 mcu_task_stddev=0.000022 bytes_write=10547015 bytes_read=2073004 bytes_retransmit=177 bytes_invalid=0 send_seq=208726 receive_seq=208725 retransmit_seq=208726 srtt=0.001 rttvar=0.001 rto=0.200 ready_bytes=0 upcoming_bytes=1717 freq=64000934 EBB: mcu_awake=0.014 mcu_task_avg=0.000017 mcu_task_stddev=0.000022 bytes_write=3374620 bytes_read=966545 bytes_retransmit=0 bytes_invalid=0 send_seq=68676 receive_seq=68676 retransmit_seq=0 srtt=0.002 rttvar=0.001 rto=0.025 ready_bytes=7 upcoming_bytes=464 freq=64000118 adj=63999430 sd_pos=2502861 EBB: temp=42.4 MANTA: temp=45.3 CB1: temp=45.9 heater_bed: target=80 temp=80.0 pwm=0.383 sysload=0.17 cputime=670.729 memavail=677976 print_time=4024.810 buffer_time=2.188 print_stall=1 extruder: target=270 temp=269.9 pwm=0.564
Stats 4020.8: gcodein=0  mcu: mcu_awake=0.120 mcu_task_avg=0.000022 mcu_task_stddev=0.000022 bytes_write=10547015 bytes_read=2073004 bytes_retransmit=177 bytes_invalid=0 send_seq=208726 receive_seq=208725 retransmit_seq=208726 srtt=0.001 rttvar=0.001 rto=0.200 ready_bytes=0 upcoming_bytes=4673 freq=64000934 EBB: mcu_awake=0.014 mcu_task_avg=0.000017 mcu_task_stddev=0.000022 bytes_write=3374620 bytes_read=966545 bytes_retransmit=0 bytes_invalid=0 send_seq=68676 receive_seq=68676 retransmit_seq=0 srtt=0.002 rttvar=0.001 rto=0.025 ready_bytes=7 upcoming_bytes=1651 freq=64000118 adj=63999430 sd_pos=2504299 EBB: temp=42.4 MANTA: temp=45.3 CB1: temp=46.2 heater_bed: target=80 temp=80.0 pwm=0.383 sysload=0.17 cputime=670.849 memavail=677740 print_time=4026.178 buffer_time=2.556 print_stall=1 extruder: target=270 temp=269.9 pwm=0.564
Filament Sensor extruder: runout event detected, Time 4021.01
Activated runout motion sensor
Exiting SD card print (position 2504340)
bed_mesh fade complete: Current Z: 20.0000 fade_target: 0.0200 
Stats 4021.8: gcodein=0  mcu: mcu_awake=0.120 mcu_task_avg=0.000022 mcu_task_stddev=0.000022 bytes_write=10547015 bytes_read=2073004 bytes_retransmit=177 bytes_invalid=0 send_seq=208726 receive_seq=208725 retransmit_seq=208726 srtt=0.001 rttvar=0.001 rto=0.200 ready_bytes=0 upcoming_bytes=6616 freq=64000934 EBB: mcu_awake=0.014 mcu_task_avg=0.000017 mcu_task_stddev=0.000022 bytes_write=3374620 bytes_read=966545 bytes_retransmit=0 bytes_invalid=0 send_seq=68676 receive_seq=68676 retransmit_seq=0 srtt=0.002 rttvar=0.001 rto=0.025 ready_bytes=7 upcoming_bytes=1979 freq=64000118 adj=63999355  EBB: temp=42.4 MANTA: temp=45.3 CB1: temp=45.6 heater_bed: target=80 temp=80.0 pwm=0.383 sysload=0.17 cputime=671.032 memavail=677816 print_time=4031.432 buffer_time=6.809 print_stall=1 extruder: target=270 temp=269.9 pwm=0.564
Stats 4022.8: gcodein=0  mcu: mcu_awake=0.120 mcu_task_avg=0.000022 mcu_task_stddev=0.000022 bytes_write=10547015 bytes_read=2073004 bytes_retransmit=177 bytes_invalid=0 send_seq=208726 receive_seq=208725 retransmit_seq=208726 srtt=0.001 rttvar=0.001 rto=0.200 ready_bytes=0 upcoming_bytes=7265 freq=64000934 EBB: mcu_awake=0.014 mcu_task_avg=0.000017 mcu_task_stddev=0.000022 bytes_write=3374620 bytes_read=966545 bytes_retransmit=0 bytes_invalid=0 send_seq=68676 receive_seq=68676 retransmit_seq=0 srtt=0.002 rttvar=0.001 rto=0.025 ready_bytes=7 upcoming_bytes=1980 freq=64000118 adj=63999195  EBB: temp=42.4 MANTA: temp=45.3 CB1: temp=46.5 heater_bed: target=80 temp=80.0 pwm=0.383 sysload=0.17 cputime=671.112 memavail=674712 print_time=4031.432 buffer_time=5.808 print_stall=1 extruder: target=270 temp=269.9 pwm=0.564
Timeout with MCU 'mcu' (eventtime=4023.838746)
Transition to shutdown state: Lost communication with MCU 'mcu'
Dumping gcode input 0 blocks

It seems your CAN network went down on the host side.

3

Hi,

had this failure multiple times too, few weeks ago.
Lost communication with MCU 'mcu'

Ender 4.2.7, Raspberry Pi 3+, EBB36 over USB.

But the → MCU ‘mcu’ ← is my Ender 4.2.7-board.
in my case the Can-Device is → MCU ‘EBBcan’ ←

On my Printers (Ender and Tronxy/VZbot) → MCU ‘mcu’ ← is always the Printer-Board…

I fixed the USB-Connection to the board and since then the failure was gone.

4

OK, thanks. Unfortunately I have a lot of negative experiences with that BTT spoof, MANTA+CB
I can’t stand it anymore.

This has never happened on Raspberry.