Update to 1.11.0 --> serial port "broken"

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1

What is the problem?

Setup: Ender3v2, Raspberry Pi4 with Octoprint. USB cable between both with "cutted" +-wire - to prevent to run the printer mainboard from the Raspberry.

Till version v1.11.0 all works fine - after starting the printer i can connect to it with the connect button. Shooting the printer down and on again, connection with connect button works again.
Update to v1.11.0: direct after start of OctoPrint and then starting the printer - connection button did not work. The only way to get it work - restart octoprint with running printer - then ONE TIME the connection button works fine. After shutting down the printer and start it again - same problem again.

What did you already try to solve it?

Check of the serial log (fired up for this test, before off) - in case of the problem i got this:

2025-04-24 15:04:16,286 - Changing monitoring state from "Offline" to "Detecting serial connection"
2025-04-24 15:04:16,306 - Performing autodetection with 0 port/baudrate candidates:
2025-04-24 15:04:16,307 - Changing monitoring state from "Detecting serial connection" to "Error"

After the restart of Octoprint instead:

2025-04-24 15:05:39,487 - Changing monitoring state from "Offline" to "Detecting serial connection"
2025-04-24 15:05:39,560 - Performing autodetection with 1 port/baudrate candidates: /dev/ttyUSB0@115200
2025-04-24 15:05:39,561 - Trying port /dev/ttyUSB0, baudrate 115200
2025-04-24 15:05:39,562 - Connecting to port /dev/ttyUSB0, baudrate 115200
2025-04-24 15:05:39,683 - Handshake attempt #1 with timeout 2.0s
2025-04-24 15:05:39,694 - Connected to: Serial<id=0xa42dbec8, open=True>(port='/dev/ttyUSB0', baudrate=115200, bytesize=8, parity='N', stopbits=1, timeout=2.0, xonxoff=False, rtscts=False, dsrdtr=False), starting monitor
2025-04-24 15:05:39,714 - Recv: echo:Unknown command: ""
2025-04-24 15:05:39,715 - Recv: ok
2025-04-24 15:05:39,722 - Send: N0 M110 N0125
2025-04-24 15:05:39,736 - Changing monitoring state from "Detecting serial connection" to "Operational"
2025-04-24 15:05:39,757 - Recv: ok
2025-04-24 15:05:39,759 - Send: N0 M110 N0125
2025-04-24 15:05:39,766 - Recv: ok
2025-04-24 15:05:39,768 - Send: N1 M115*39
2025-04-24 15:05:39,806 - Recv: FIRMWARE_NAME:Marlin 2.1.2.5 (Feb 17 2025 18:39:55) SOURCE_CODE_URL:github.com/MarlinFirmware/Marlin PROTOCOL_VERSION:1.0 MACHINE_TYPE:Ender-3 V2 EXTRUDER_COUNT:1 UUID:cede2a2f-41a2-4748-9b12-c55c62f367ff

Have you tried running in safe mode?

Yes - and there is no problem! So points to a Plugin?

Did running in safe mode solve the problem?

See above.

Systeminfo Bundle

You can download this in OctoPrint's System Information dialog ... no bundle, no support!)
octoprint-systeminfo-20250424152030.zip (129.2 KB)

WRITE HERE

Additional information about your setup

OctoPrint version, OctoPi version, printer, firmware, browser, operating system, ... as much data as possible

WRITE HERE

2

have you handled backpowering?

3

Yes - the plus-wire of the usb cable is disconnected.

And the setup has worked for two years before the update without any problems ... so something has changed with v1.11.0.

4

I also seem to have the same problem, but maybe another flavor?

I use the PSU control plugin to control my Prusa mk4s. And it seems, that when the "auto connect" after power on from the plugin works, everything is fine. Disconnecting and reconnecting works without any problems once the initial connection worked. But when the plugin was unable to connect (the printer boot up sometimes takes some seconds longer), I can not connect anymore trough the UI. And the serial output looks, like it does not even try to connect when I hit the UI button. Nothing is happening in the serial console.

So it could be (just guessing) that something like this is the problem in my setup:

  • The PSU plugin somehow blocks further connection attempts when it was unable to connect after power on
  • Octoprint blocks further connection attempts after a plugin reports an error

There is currently no open issue I was able to find in Octoprint or the PSU control plugin which matches the problems here.

@stefan_octo do you also use the PSU control plugin?

5

yes - i use the PSU control plugin and PSU control Tapo (to switch with an Tapo device). I updated both to the newest version, without success.

And good to hear - another printer - same problem. So that points to soft- instead of hardware.

6

... and here is the solution (for me): in the PSU control plugin under "power on options" i have switched off the "connect when powered on" ... and now it works again as before / expected.

So seems the "autoconnect" of the PCU control plugin blocks the connect button.

psu
psu1018×1126 101 KB

1 Like
7

@kantlivelong might want to know.

8

Hi, first post here because I too have trouble with my serial connection. I do not use the PSU control plugin, but after updating to 1.11.0 the serial connection to my Creality CR10 V3 stopped working.
I see this in my terminal window:

Unexpected error while reading serial port, please consult octoprint.log for details: SerialException: 'device reports readiness to read but returned no data (device disconnected or multiple access on port?)' @ comm.py:_readline:4175
Please see OctoPrint randomly loses connection to the printer with a "SerialException" - FAQ - OctoPrint Community Forum for possible reasons of this.
Changing monitoring state from "Operational" to "Offline after error"
Connection closed, closing down monitor.

Nothing has changed, the USB cable is OK, and the power-wire is cut, so no back powering from the RPI. I did try another USB cable but have the same issue. All was working for about two years without any issues, so I am at a loss.

9

please share system info bundle.

10

Here is my system info bundle. Hope this helps, if there are more questions I will be happy to answer them in order to fix this.

octoprint-systeminfo-20250426073826.zip (44.1 KB)

11

I now see that serial log is not enabled, I will make and share a new system bundle as soon as I can. I am not at home right now.

12

looks like it also rotated the log, so there isn't even a printer connection attempt in it. also try restarting in safe mode just to make sure it's not a plugin issue.

13

Hi jneilliii, Thanks for your answers so far. I have restarted everything (the raspberry and the printer) and it connected to the printer and now it is printing a 12 hour print job. Serial log is enabled and I expect it to fail at some point.
I will keep an eye on it and when there is a failure I will let you know. Also if it does not fail I will keep you updated.
I do not think it is a plugin failure, I only have two extra plugins installed, Octorelay and Octolapse.
But I will try safe mode next.

14

Hi @jneilliii ,
Printer went well through the night, but just as I got up this morning, it stopped, the system bundle is pretty big but here is the bit of the serial.log that is the important bit.

2025-04-27 07:00:41,816 - Recv: ok N679331 P0 B3
2025-04-27 07:00:41,817 - Send: N679332 G1 X161.925 Y109.263 E497.56422*82
2025-04-27 07:00:41,829 - Recv: ok N679332 P0 B3
2025-04-27 07:00:41,830 - Send: N679333 G1 X161.94 Y109.564 E497.57424*103
2025-04-27 07:00:41,858 - Recv: ok N679333 P0 B3
2025-04-27 07:00:41,859 - Send: N679334 G1 X161.893 Y109.865 E497.58437*94
2025-04-27 07:00:41,871 - Recv: ok N679334 P0 B3
2025-04-27 07:00:41,872 - Send: N679335 G1 X161.797 Y110.115 E497.59328*90
2025-04-27 07:00:41,883 - Recv: ok N679335 P0 B3
2025-04-27 07:00:41,884 - Send: N679336 G0 F9000 X164.034 Y108.744*115
2025-04-27 07:00:41,895 - Recv: ok N679336 P0 B3
2025-04-27 07:00:41,896 - Send: N679337 G1 F1800 X163.977 Y108.661 E497.59663*50
2025-04-27 07:00:41,906 - Recv: ok N679337 P0 B3
2025-04-27 07:00:41,907 - Send: N679338 G1 X163.415 Y108.059 E497.62402*91
2025-04-27 07:00:41,917 - Recv: ok N679338 P0 B3
2025-04-27 07:00:41,918 - Send: N679339 G1 X163.239 Y107.758 E497.63562*93
2025-04-27 07:00:41,928 - Recv: ok N679339 P0 B3
2025-04-27 07:00:41,929 - Send: N679340 G1 X163.156 Y107.457 E497.646*85
2025-04-27 07:00:41,964 - Recv: ok N679340 P0 B3
2025-04-27 07:00:41,965 - Send: N679341 G1 X163.141 Y107.156 E497.65603*84
2025-04-27 07:00:44,969 - Communication timeout while printing, trying to trigger response from printer. Configure long running commands or increase communication timeout if that happens regularly on specific commands or long moves.
2025-04-27 07:00:44,970 - Send: N679342 M105*26
2025-04-27 07:00:47,973 - Communication timeout while printing, trying to trigger response from printer. Configure long running commands or increase communication timeout if that happens regularly on specific commands or long moves.
2025-04-27 07:00:47,974 - Send: N679343 M105*27
2025-04-27 07:00:50,974 - Communication timeout while printing, trying to trigger response from printer. Configure long running commands or increase communication timeout if that happens regularly on specific commands or long moves.
2025-04-27 07:00:50,976 - Send: N679344 M105*28
2025-04-27 07:00:53,979 - Communication timeout while printing, trying to trigger response from printer. Configure long running commands or increase communication timeout if that happens regularly on specific commands or long moves.
2025-04-27 07:00:53,980 - Send: N679345 M105*29
2025-04-27 07:00:56,983 - Communication timeout while printing, trying to trigger response from printer. Configure long running commands or increase communication timeout if that happens regularly on specific commands or long moves.
2025-04-27 07:00:56,984 - Send: N679346 M105*30
2025-04-27 07:00:59,987 - No response from printer after 6 consecutive communication timeouts, considering it dead. Configure long running commands or increase communication timeout if that happens regularly on specific commands or long moves.
2025-04-27 07:00:59,999 - Changing monitoring state from "Printing" to "Offline after error"
2025-04-27 07:01:00,004 - Connection closed, closing down monitor
2025-04-27 07:22:09,701 - Changing monitoring state from "Offline" to "Detecting serial connection"
2025-04-27 07:22:09,724 - Performing autodetection with 1 port/baudrate candidates: /dev/ttyUSB0@250000
2025-04-27 07:22:09,724 - Trying port /dev/ttyUSB0, baudrate 250000
2025-04-27 07:22:09,726 - Connecting to port /dev/ttyUSB0, baudrate 250000
2025-04-27 07:22:09,782 - Handshake attempt #1 with timeout 2.0s
2025-04-27 07:22:09,783 - Connected to: Serial<id=0x9e9df178, open=True>(port='/dev/ttyUSB0', baudrate=250000, bytesize=8, parity='N', stopbits=1, timeout=2.0, xonxoff=False, rtscts=False, dsrdtr=False), starting monitor
2025-04-27 07:22:09,786 - Send: N0 M110 N0*125
2025-04-27 07:22:10,688 - Recv: start
2025-04-27 07:22:10,691 - Changing monitoring state from "Detecting serial connection" to "Operational"
2025-04-27 07:22:10,716 - Send: N0 M110 N0*125
2025-04-27 07:22:10,718 - Recv:  External Reset

I had to reset the printer because it was not reacting to anything I did, I tried to cancel the print but that did not work. I filmed a little movie to show what was happening. The printer was still "printing" but nothing happened, the printhead did not move anymore but the display said "printing"

check the movie here: Creality_CR10_V3.MOV

the system bundle is here: octoprint-systeminfo-20250427072518.zip

15

Please, when updating information: Always post the complete systeminfo bundle.
And please: When posting code, use the Preformatted Text feature of the forum editor for it. Its much more easy to read.

Format

16

Sorry for that, I corrected my post, thanks for reminding me.

1 Like
17

Yeah, serial log doesn't show anything to indicate why, the printer literally just doesn't reply and never responds again as pointed out in the excerpt you show. You could try forcing a reinstall to start.

/home/pi/oprint/bin/pip install --force-reinstall --no-cached-dir octoprint==1.11.0

or downgrade the version.

/home/pi/oprint/bin/pip install --force-reinstall --no-cached-dir octoprint==1.10.3
18

Thanks for those commands, I will try to re-install first but as far as I could tell during the upgrade nothing went wrong, no errors were displayed and everything seems to work OK.
I might as well try a downgrade if the re-install don't work.

I will let you know how things go.

Thanks!