Unable to succesfully use Klipper on PC

Basic Information:

Printer Model: Ender 3 Neo
MCU / Printerboard: V4.2.2 GD32F303RET6
klippy.log (107.1 KB)

I do not have a RPi, so I used KIAUH and my Ubuntu 22.04.04 LTS Desktop laptop to use it instead of the RPi and connect it to my Ender 3 Neo printer. In the KIAUH, I have 3 options to select from [Get MCU ID], 1) USB, 2) UART, 3) USB (DFU mode) instead of 2 as I usually see from other posts.

When I select 1 and 3 I get the “No MCU found! MCU either not connected or not detected!”
When I select 2 I get MCU #1: /dev/ttyS0.

I do not have folder /dev/serial/. I checked if I had CH340 drivers, as my board has on it the chip CH340G. I found that ch340 drivers are probably corrupted, so I installed them through this GitHub GitHub - juliagoda/CH341SER: CH341SER driver with fixed bug and following also, some of the check points used by this YouTuber https://www.youtube.com/watch?v=Y2mvdlnqRzA. I tried previously the newer version but did not work…
I also have the latest version of Kernels.

The printer can be seen with lsusb as “Bus 002 Device 015: ID 1a86:7523 QinHeng Electronics CH340 serial converter” and I have masked and stopped brltty. Also at dmseg.txt I can see the printer as “udevadm info --attribute-walk /dev/pci0000:00/0000:00:14.0/usb2/2-1/2-1:1.0/tty/ttyCH341USB0”. However, the Manufacturer is not Klipper… I attach also the dmseg.txt.

I don’t know what to do, or what is wrong. I used many different bin files for flashing the printer. Always with Baudrate at 115200 as the Creality gave me at the supplementary files in the SD and

Micro-controller Architecture (STMicroelectronics STM32) —>
Processor model (STM32F103) —>
Only 10KiB of RAM (for rare stm32f103x6 variant)
Disable SWD at startup (for GigaDevice stm32f103 clones)
Bootloader offset (28KiB bootloader) —>
Clock Reference (8 MHz crystal) —>
Communication interface (Serial (on USART1 PA10/PA9)).

I have also tried the default Baudrate 250000 and USART3 PA11/PA10 and all the combinations.
I have fully uninstall and reinstall all the package for KIAUH and Klipper etc, but nothing works.

If anyone can help, please reply. Thank you!

dmesg.txt (198.2 KB)


It sounds like your board hasn’t been properly flashed. Maybe this will help with your particular board: Support for new Creality boards 4.2.2 with GD32F303 - #54 by vecktor

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Work through Issues flashing the printer board and especially mind the chapter Linux Issues WRT Modemmanger / BRLtty

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Thank you @theophile for your answer! It works but unfortunately only when safe boot is turned of, because the CH340 drivers were unsigned. I try to sign them so to solve the problem. I tried openssl and creat a signature, but I cannot find a way to sign the already uploaded ch340.
Do you have any idea how to do so?

Thank you @Sineos for the guidelines, I found also some other things about Ubuntu, that I was suspecting but I wasn’t sure. As I wrote to @theophile the connection is achieved only when safe boot is turned off. I have created the cert.pem, csr.pem and key,pem through openssl. Do you know how to sign the already loaded CH340 drivers, so that I could use Klipper in safe boot?

I’m not sure what steps you followed but the Linux kernel has had CH340 support for a long time so there should be no need for using unsigned or out-of-tree drivers.

Okay… I read some posts online that claimed that CH340 drivers were corrupted. So I probably caused an additional problem to myself… I will try to find a way to remove the CH340 drivers I added. I will do so, and if it works afterwards I will mark the issue Solved.
Thank you @theophile !

@theophile indeed Linux kernel has CH340. My old Ubuntu had corrupted CH340 drivers, this is why Klipper didn’t connect without the out-of-tree drivers. I reinstalled Ubuntu from the beginning and the problem is solved! Thank you for the help!