Lost communication with MCU 'mcu' | Mainsail | Page 1

fringe oxide Jan 30, 2023, 12:10 PM

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Hi !
I installed Klipper on my Ender 3 S1 Pro following the documentations steps, I use the printer.cfg file in the Klipper Github (the only difference is that I added my input shaper parameters).
The prints were incredibly better and it worked really well.
It's been a couple of days that the connection is lost between the RPi 3b+ and ther printer. The print then stops at the very beginning.
The mainsail dashboard shows :
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

In the logs (klippy.log) : Attached file

In dmesg :
[ 240.742134] ch341-uart ttyUSB0: usb_serial_generic_read_bulk_callback - urb stopped: -32 [ 550.023148] ch341-uart ttyUSB0: usb_serial_generic_read_bulk_callback - urb stopped: -32 [ 589.847405] ch341-uart ttyUSB0: usb_serial_generic_read_bulk_callback - urb stopped: -32

I tried to change the USB cable, uninstall, reinstall Klipper, update and upgrade RPi package, upgrade RPi software, replace RPi power supply by official plug, and nothing works.

Any ideas ?

📎 message.txt

fringe oxide Feb 1, 2023, 9:09 PM

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I still have the problem if anyone has a idea I'll take it

cedar star Feb 1, 2023, 9:12 PM

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What kind of power supply are you using for your PI?

fringe oxide Feb 1, 2023, 9:34 PM

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A buck converter from the printer power supply, however I tryed to change and use the official RPI power supply plug in the wall and still had the problem

odd lantern Feb 1, 2023, 9:44 PM

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I have the same problem with my ender 5 + with a MKS Robin E3.
If you find a solution, let me know, I will do the same if I can find something

fringe oxide Feb 1, 2023, 9:46 PM

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I had the problem on each of my prints, I tried to unplug the webcam and it avoided the problem for one print, now I have it again and no webcam lol

odd lantern Feb 1, 2023, 9:47 PM

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On my side, it's using CH340C driver for the USB <-> UART convertion, I have some doubts on this one.

But at the moment my printer run for small prints without problems, the last week on each print I saw the problem

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and nothing changed but it's working at the moment

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But i'm sure it will come back

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I checked, there is no power delivered on the USB coming from my MCU

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there is a jumper to remove to be sure it is not powered by MCU, on my side it's already removed

fringe oxide Feb 3, 2023, 4:54 PM

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I tried to boost the power to 5.25V for the RPi according to the limit input voltage. It didn't work, still have the same problem.
At this point I am just tired, I can't print anything it crashes too early. I am gonna install klipper on an old PC. I'll know if the problem came from the RPi or the printer

hexed kettle Feb 12, 2023, 7:43 AM

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Im having the same exact issue cant get my printer to go for more then 30 minutes before i get the MCU error. Im losing my mind trying to figure it out. Did you ever figure out a fix?

📎 klippy_3.log

dark stirrup Feb 14, 2023, 6:30 AM

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I don’t know how many ways there are to generate this error, but I too have started getting random shutdowns of my system, with “Lost communication with mcu”. I suspected a cheap usb hub between the pi and the peripherals, including my C920 webcam and my HDMI touchscreen USB cable, but the printer is connected directly to the pi. Nothing in Klipper.log, just loss of comms as if Klipper.bin or the Watchdog timer function dropped the USB connection from the printer side. FIRMWARE_RESTART fails, in my case, saying the mcu is shutdown and can not be reinitialized.. I have to cycle printer power to restart Klipper.

dark stirrup Feb 15, 2023, 9:36 PM

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fringe oxide I tried to boost the power to 5.25V for the RPi according to the limit input vol...

Any difference running off a PC?

fringe oxide Feb 15, 2023, 10:48 PM

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Sorry for coming back so late, yes I installed Ubuntu on an old PC and it works perfectly. The problem then doesn't come from the printer or the USB cable

dark stirrup Feb 16, 2023, 2:13 AM

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fringe oxide Sorry for coming back so late, yes I installed Ubuntu on an old PC and it works ...

Probably a power supply issue on my pi, then.
I had a powered USB hub plugged in to the pi, without a power blocker. I am trying that, now.

fringe oxide Feb 16, 2023, 12:15 PM

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I really don't think so, I tryed many things : using the official RPi power supply (5.1v 2.5A), it didn't work so I put a buck converter from the printer power supply, I first setup the converter to 5v (3.5A) it didn't work so I boosted it to 5.1v and didn't wort neither.
So I took a look at the Raspberry documentation and it talks about 5v ± 5% so I boosted the power to 5.25v and it didn't work.
I forgot to precise that I had a power warning (power going down 4.65v) even with the official power supply but when measuring it never went under 5v. WIth 5.25v I didn't longer had the warning but it kept crashing. (Also tried to replace the USB cable between the buck converter and the Pi but nothing)
With all of this I rather think that it is a software issue.

#Lost communication with MCU 'mcu'