[SOLVED] octoprint... help? no serial no ttyUSB

Operating Systems & Open Source
21

now is a good time to say HOLY F"CKING SHIT!! and WTF.
after digging on the internet for hours on end i finally found a solution and i've connected to my printer.
However in the meantime i also installed arduino onto the rpi (probaly did not make it work)

But what i found is:
this Forum
and what i did myself was (via SSH)

pi@octopi:~ $ modprobe ftdi-sio
pi@octopi:~ $ sudo chmod 666 /sys/bus/usb-serial/drivers/ftdi_sio/new_id
pi@octopi:~ $ nano /sys/bus/usb-serial/drivers/ftdi_sio/new_id

and insert "0403 8a8a" without the quotes, hit ctrl+x and save
Plug out your printer, and plug it back in.

pi@octopi:~ $ ls /dev

and there you go, a perfectly fine ttyUSB0!

i'll do a total clean install of octoprint and try this again.

22

Yep it is working.. stunned.

pi@octopi:~ $ sudo modprobe ftdi-sio
pi@octopi:~ $ sudo chmod 666 /sys/bus/usb-serial/drivers/ftdi_sio/new_id
pi@octopi:~ $ nano /sys/bus/usb-serial/drivers/ftdi_sio/new_id

and insert "0403 8a8a" without the quotes, hit ctrl+x and save
Plug out your printer, and plug it back in.

pi@octopi:~ $ ls /dev
23

Weird! it seems the USB hardware isn't what the USB driver was expecting, if I understand that right.
Congrats on persevering and fixing it! That's what computers are all about.

24

Indeed, however i have to do it everytime i restart the PI, so i made a little script.

For anyone else that might have this problem in the future or comes across this thread.
This is for you.

in /root
i made a file called "new_id" in that file i put "0403 8a8a" (replace with your printer id if needed) and saved it
and i made a shell script called starth.sh as follow.

#!/bin/bash

sudo modprobe ftdi-sio
sudo cp /root/new_id /sys/bus/usb-serial/drivers/ftdi_sio/
sudo chmod 666 /sys/bus/usb-serial/drivers/ftdi_sio/new_id

saved it and made it executable (with "chmod +x starth.sh")

then i went to edit crontab (with command "sudo crontab -e")
and added

@reboot /root/starth.sh

saved it and restarted the pi.
Now everything just works!

25

Setup: octorpint 1.7, Pi4 & Pi3, image from Raspberry (Oct 2021), Creality Ender 3

I had symptoms similar to this case.

No ttyUSB0. Suspected that ttyS0 was the intended target, but that was not so.
I tried ‘sudo modprobe ftdi-sio’ and creating the entry in the /sys/bus. === > no cigar.

Chmod’ing the permissions on ttyS0, ttyAMA0 to ‘0666’ and attempting connection with Octoprint still would not connect,
and the permissions would change right back with the next ‘ls’.

I tried one other thing along this line and that was to add a new exception (rule) in: /etc/udev/rules.d/local.rules (make a new file with):
ACTION==“add”, KERNEL==“ttyS0”, MODE=“0666”

This also had no effect recordedin: dmesg, /var/log/syslog, or terminal dialog

Another thread suggested a chmod race condition against udev was suspected.

There was responses on Terminal dialog that continued to suggest a permissions issue.
I turned to start comparing to a working setup. I was fortunate to have another octoprint pi with a working setup. Starting with permissions and users:

  1. to be clear, the octoprint user is likely different from root
  2. ensure the octoprint user has privileges in:

tty, netdev, dialout, adm, sudo, users, pi, and root.

It was the last one that was key in my case. Once I added root privileges to my octoprint user:
a) the ttyUSB0 was created dynamically on serial/usb connection
b)dmesg would reflect with several lines including the ftdi and ch341 chips.
c) a tail of /var/log/syslog immediately showed the creation of the ttyUSB0

Also ensure that the serial lines are enabled in raspi-config. First question is ‘no’ (use for console) second one is ‘yes’. (enable hdw)

All issues went away.