Open Source: SimRacing 14Bit Handbrake Custom Firmware

Most of you, probably know these "SimRacing 14Bit Handbrake" from AliExpress or eBay (see image), I wrote a custom "firmware" that allows to connect more buttons or axes to it

Download:
The Arduino Sketch is available on my GitHub. Please have a look at the README for instructions.
https://github.com/Dak0r/Chinese-SimRacing-14Bit-Handbrake-Custom-Firmware-Arduino-Sketch

More Info:
I bought one and noticed that it's using an Arduino Pro Micro Clone and a HAL sensor.
Seeing all those unused pins on the Arduino, I decided to engineer the software that is installed on the Arduino, so one could make use of the other pins, without changing the handbrakes original behavior.

My sketch is designed as a drop-in replacement and works just like the original firmware, regarding the mapping of the HAL-Sensor values to the joystick axis. As an example for how to extend this sketch, it also defines two joystick buttons which get triggered, if pin 2 or 3 are connected to ground. (I used the well known ArduinoJoystickLibrary from MHeironimus, see Readme).

I used this to connect my DIY Shifter to my PC, without having yet another USB Device. But a button box or such is of course also possible.

Overall it's nothing too fancy and the project is already a little older, but I thought someone here might find this useful anyway

When I try to upload the code I get an error message. How can I make it work?

Sketch uses 9272 bytes (32%) of program storage space. Maximum is 28672 bytes.
Global variables use 346 bytes (13%) of dynamic memory, leaving 2214 bytes for local variables. Maximum is 2560 bytes.
avrdude: ser_open(): can't open device "\\.\COM3": The system can not find the given file.


Failed uploading: uploading error: exit status 1

Thank you Dakor!
Thanks to this, I was able to repair the broken board and make it work perfectly.
It was my first time using Arduino, but thanks to my previous job, I was able to access it without much difficulty.
The problem was that the port was not assigned, so I couldn't find the problem, and I was confused...
I replaced the USB cable after realizing it was not for data transmission.
The mini pro board, which only had a green LED on, turned on a red light and data was sent and received, and it worked perfectly right away!

If anyone struggles with ports like me, suspect the cable!
Dakor's explanations and materials are perfect!

(This is a Google translation, so please understand if there are any awkward expressions.)