Serial connection error (Ubuntu 14.04 LTS)

fader · 4 Dec 2015, 21:43

@Enrico-Bermudez If the module is present already (i.e. modinfo gives you output), try just "sudo modprobe cp210x". That should make Linux pull in all the dependencies automatically and be easier to deal with than insmod.

(Also worth noting on Ubuntu, when /dev/ttyUSB0 gets created, no user account will have permission to access it. You'll need to use "sudo screen /dev/ttyUSB0 115200" or add yourself to the dialout group with "sudo usermod -a -G dialout [your_user_name]" and then log out and back in again.)

Enrico Bermudez · 5 Dec 2015, 01:31

@fader , I get an "Exec format error" when I do a modprobe on cp210x

Enrico Bermudez · 5 Dec 2015, 02:11

@Lazar-Demin , here you go:

Enrico Bermudez · 5 Dec 2015, 02:18

@Sawyer-McBride , I changed the USB cable, but there was no change in status. The issue persists. Thanks for the tip.

Boken Lin · 5 Dec 2015, 02:49

@Enrico-Bermudez Are you on 64 bit or 32 bit? If my compilation works I can send you the .ko file.

Enrico Bermudez · 5 Dec 2015, 03:13

@Boken-Lin, I'm on a 64-bit machine. (x86_64)

Boken Lin · 5 Dec 2015, 03:26

@Enrico-Bermudez Ok, here it is: https://s3-us-west-2.amazonaws.com/onion-cdn/community/openwrt/cp210x_driver.tar.gz.

Try the following:

Untar
copy usbserial.ko to /lib/modules/3.13.0-68-generic/kernel/drivers/usb/serial/
copy cp210x.ko to that folder as well
insmod /lib/modules/3.13.0-68-generic/kernel/drivers/usb/serial/usbserial.ko
insmod cp210x.ko

The above procedure worked for me on Ubuntu 14.04 x64.

Cheers.

Enrico Bermudez · 5 Dec 2015, 12:24

@Boken-Lin You're at 3.13.0-68-generic, while I'm at 3.13.0-53-generic.

Not sure if the slight change in kernel version will be an issue. But I tried it anyway.

I still got the 'Invalid module format' error.

Let me see if I can update the kernel to the same version and try again.

And if that doesn't work, I may end up upgrading to 15.10.

Boken Lin · 5 Dec 2015, 20:46

@Enrico-Bermudez Ok. I wasn't able to get kernel version 3.13.0-53 anymore. I was only able to find the Ubuntu image with the updated kernel. I think you might need to perform apt-get dist-upgrade to upgrade the kernel.

Enrico Bermudez · 6 Dec 2015, 21:48

@Boken-Lin , Kernel upgrade didn't go up to 3.13.0-68-generic for some reason.
I can only bring it up to 3.13.0-55-generic. insmod seemed to work, but the connection still isn't working.

After all those failed attempts, I decided to upgrade to the latest long-term supported kernel 4.1.13. I used the instructions shown at:
http://linuxg.net/install-kernel-4-1-x-on-ubuntu/

Then followed the instruction for installing the cp210x driver.

And the serial connection works now!

Boken Lin · 6 Dec 2015, 22:00

@Enrico-Bermudez Yay! That's great news!

Enrico Bermudez · 7 Dec 2015, 01:13

Thanks for all your help, @Bokin! I learned a lot just going through this process with you.

Boken Lin · 7 Dec 2015, 03:38

@Enrico-Bermudez No problem! That's what we are here for It's a learning experience for us as well. We'll know what to do to help people through similar issues!

Christiaan Scholtz · 7 Dec 2015, 06:57

fyi I had the same problem on a fresh install of ubuntu 14, no USB devices listed. But after some time when i tried again it simply worked by itself.