Printer not detected by OctoPrint

What is the problem?

Can't connect to printer

What did you already try to solve it?

I've tried multiple cables (I don't think that's the problem, since I can control my printer using a windows pc with cura)

I've also verified that the printer is recognized by the computer. Here are the last few lines when I run dmesg:

Printer connected

[ 924.773499] ch341 1-8:1.0: ch341-uart converter detected
[ 924.774242] usb 1-8: ch341-uart converter now attached to ttyUSB0
[ 1312.634738] usb 1-8: USB disconnect, device number 5
[ 1312.635044] ch341-uart ttyUSB0: ch341-uart converter now disconnected from ttyUSB0
[ 1312.635080] ch341 1-8:1.0: device disconnected
[ 1588.955125] usb 1-8: new full-speed USB device number 6 using xhci_hcd
[ 1589.104528] usb 1-8: New USB device found, idVendor=1a86, idProduct=7523, bcdDevice= 2.64
[ 1589.104540] usb 1-8: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[ 1589.104546] usb 1-8: Product: USB Serial
[ 1589.106064] ch341 1-8:1.0: ch341-uart converter detected
[ 1589.106552] usb 1-8: ch341-uart converter now attached to ttyUSB0
[ 1770.976358] usb 1-8: USB disconnect, device number 6
[ 1770.976769] ch341-uart ttyUSB0: ch341-uart converter now disconnected from ttyUSB0
[ 1770.976807] ch341 1-8:1.0: device disconnected
[ 1919.307387] usb 1-8: new full-speed USB device number 7 using xhci_hcd
[ 1919.456733] usb 1-8: New USB device found, idVendor=1a86, idProduct=7523, bcdDevice= 2.64
[ 1919.456746] usb 1-8: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[ 1919.456752] usb 1-8: Product: USB Serial
[ 1919.459572] ch341 1-8:1.0: ch341-uart converter detected
[ 1919.460855] usb 1-8: ch341-uart converter now attached to ttyUSB0

Printer disconnected

[ 924.773499] ch341 1-8:1.0: ch341-uart converter detected
[ 924.774242] usb 1-8: ch341-uart converter now attached to ttyUSB0
[ 1312.634738] usb 1-8: USB disconnect, device number 5
[ 1312.635044] ch341-uart ttyUSB0: ch341-uart converter now disconnected from ttyUSB0
[ 1312.635080] ch341 1-8:1.0: device disconnected
[ 1588.955125] usb 1-8: new full-speed USB device number 6 using xhci_hcd
[ 1589.104528] usb 1-8: New USB device found, idVendor=1a86, idProduct=7523, bcdDevice= 2.64
[ 1589.104540] usb 1-8: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[ 1589.104546] usb 1-8: Product: USB Serial
[ 1589.106064] ch341 1-8:1.0: ch341-uart converter detected
[ 1589.106552] usb 1-8: ch341-uart converter now attached to ttyUSB0
[ 1770.976358] usb 1-8: USB disconnect, device number 6
[ 1770.976769] ch341-uart ttyUSB0: ch341-uart converter now disconnected from ttyUSB0
[ 1770.976807] ch341 1-8:1.0: device disconnected

Systeminfo Bundle

octoprint-systeminfo-20230101194732.zip (78.9 KB)

Additional information about your setup

my setup:

  • Ender 3 pro with the 4.2.7 board
  • Marlin bugfix-2.1.x
  • Octoprint running on a computer with Ubuntu 22.04.1 LTS
  • Octoprint version 1.8.6

I think it is on Ubuntu 22.04 (or maybe 20.04, can't remember) that you have to disable/uninstall the brltty service for it to work.

Try sudo apt remove brltty, reboot and try connecting again?

Hey, thanks for the reply. brltty isn't installed on my computer, so that's not the problem.

What guide did you use to install OctoPrint on Ubuntu?

I used this.

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Allright, I feel kind of dumb. Turns out I just forgot to run these lines:
sudo usermod -a -G tty pi
sudo usermod -a -G dialout pi

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