I just turned my printer back on after a few months. I got the message that updates are available so I pressed update which worked fine. Then I got the message that my python is nearing the end-of-life I looked up how to update that. I made a backup and reinstalled Octo print on my Raspberry pi 4. After uploading the backup, I noticed that my Octoscreen isn’t working anymore and I just get the classic Linux terminal. When restarting my printer and the raspberry PI I get the error message: “No more candidates to test, and no working port/baudrate combination detected.” Earlier then going Truong my settings Octoprint even found the port my printer was connected to when trying to switch between Auto and a specific por. Not it doesn’t even show that anymore. When trying to connect my printer to my pc running printer face I get some garbage messages since Klipper is relying on the raspberry pi to communicate to my PC.
What did you already try to solve it?
Connecting directly to Pronterface
Restarting multiple times
messing around with settings in Octoprint
octoprint-systeminfo-20251018122506.zip (17.7 KB)
Here my Systeminfobundle.
Today as I opened octoprint.local I got the error message that my printer.cfg is missing. Even after trying to re upload my latest backup I still get the same error message.
Ou hmm that was a long time ago when I set that up. As far as I can remember I am running klipper but it only controls my steppers and does not calculate any of the movements from the gcode. The calculations are completely done by the raspberry pi
I just uploaded a Backup of my Printer.cfg and now it at least detects my printers usb port but I still can't connect to it. The error message I get is "no more candidates to test".
When you have Klipper on the printer, you do not connect OctoPrint to the Print, but to Klipper.
Usually this is serial port /tmp/printer.
Within the printer.cfg is the information how Klipper connects to the printer.
Please have a bit patience. This thread is not that old.
To give us a helping hand, you may describe your issue in more detail.
From our experience, there is no
Same issue. Everything was running fine for 4 years, got the notification that python was EOL and to upgrade. Did a backup/reinstall of octoprint/restore and about 90% of the time the printer wont connect to octoprint (Its plugged in via serial over GPIO pins on a raspi3B)
randomly if i reboot the octoprint and the printer over and over it sometimes connect. but 30-60 minutes of fiddling is a nightmare before every print.
Have you done anything related to your dtoverlay settings in the past that you forgot to do again on the new image?
I remember there being some issues with the GPIO serial being set to software by default and the Bluetooth device getting put on the hardware serial, and that having to get swapped by a device tree overlay in /boot/firmware/config.txt for stuff to work properly with GPIO serial communication.
dtoverlay=disable-bt
maybe? It's been a while.
In general ttyS0 sounds like that overlay is missing, I think once properly configured you should see ttyAMA0 instead.
Sorry for my late reply,
I remember I had to mess around with some dtoverlay lines to get my screen for octoscreen to work (which now also doesn't work). Could it have something to do with that?
Possibly, yes. I suggest you first concentrate on getting your serial moved to the actual hardware serial (see the link I posted above) and then look into the display.
