Lost communication with MCU 'mcu' again

General Discussion
1

Basic Information:

Printer Model: Ender 3 V1
MCU / Printerboard: Creality v1.1.4
Host / SBC : Raspberry pi 4 modell B
klippy.log (5.1 MB)

klippy.log

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:

Klipper reports: 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
Hey you all i get this error messege all the time with my old ender 3 i just upgraded to klipper (i had this problem before with octoprint but not nearly as much i used to get a asimilar mesege about 1-2 days). I sometimes can get like 1 hour of printing done , but other times i get this error after 15 min. I read a lot of posts about this i tried changing the usb cable to the printer 2 times , and I used 4 usb c power bricks for my pi the last one was a 100w power supply. I unplugged the camera and im only using some basic stuff in the printer.cfg.

2

Unfortunately, this is an error that can be hard to diagnose, but you need to search it in your hardware setup first and foremost.
The known reasons for this issue are listed here: Timeout with MCU / Lost communication with MCU

3

Yes but i unfortunetly already tried all the options in thet thread

4

There’s a few EOF (End of File)'s shown in the comms flow, which might suggest a break in the serial connectivity.
What’s the PI->MCU connection path? I can see on the PI side it’s USB, and an ATMega128 at the MCU end… I’m not aware of the ATMega having onboard USB, so I suspect there’s a USB->Serial adapter in the middle.
It’s possible this is causing a problem. You could play around with trying a different adapter.
But I’d probably just swap out the mainboard with something ‘newer’… they’re plenty cheap at this lower end. Just like an SKR 1.3 should do it…
then you’d have more MCU power to play with too

5

I had similar problems with an old computer running Octoprint, problems with the oxidized USB port, I also had problems with the Dupoint type wires oxidized in the connectors or pins, and to help with the USB cable near the electrical network, my Chinese caliper does not turn off near the monitor. There are so many possibilities. I remembered the power source too.

6

@BevanWeiss and @ejhones both have some good points there

The “working theory” is:

  1. There are no systematic issues or bugs known in this area
  2. It works for thousands and thousands of printers
  3. Having this issue is very likely something hardware related on your side that makes the connection between your RPi and the board unstable OR makes the board itself unstable
  4. Identifying this “something” from the point 3 can be a tedious task
  5. The items listed in the linked article are, to our best knowledge, the reasons why this is happening. If you can identify a new reason, I’ll be happy to amend the list
7

I had an mks genl board and we getting this error once in a while. Tried everything never found a solution. Then the board fried a driver and died. Replaced the board with a SKR 1.4 and never had the problem again. Made me start to think it’s probably mainly an old/cheap board issue. never had it even once on my spider based voron.

8

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