Enhance: Sofle Choc: Automatic left/right detection

[t-8ch]

What feature would you like to see?

Currently the left/right detection in the Sofle Choc is done by assuming the cable is plugged into the left half.
(As proposed in the code at qmk/qmk_firmware#16736 )
This restricts the user a bit.

QMK can also detect the sides based on a GPIO pin.
As the pin D4 of the controller is not used on the current PCB there could be a jumper or direct connection from D4 to VCC on one and GND on the other PCB side.

Are you prepared to help?
My EDA skills are limited and I already have my Sofle Chocs and can work around it with a physical wire :-)

Cc @brianlow

[t-8ch]

So a jumper doesn't really make sense.

Instead of connecting both D4 holes between the two mounting sides of the pro-micro should not be connected with each other instead one is connected to VCC and one to GND.

[7oo1er]

Hello.

I use RGB version with a RP2040. Config.h looks like:

// #define MASTER_LEFT
// #define MASTER_RIGHT
#define EE_HANDS

#define SPLIT_USB_DETECT
#define SPLIT_USB_TIMEOUT_POLL 10
#define SPLIT_WATCHDOG_ENABLE
#define SPLIT_WATCHDOG_TIMEOUT 3000

Builds with:
qmk flash -c -kb sofle -km rgb_default -e CONVERT_TO=promicro_rp2040 -bl uf2-split-left
uf2-split-left or uf2-split-right for each side.

Not sure if it`s fully correct, but in this case USB can be plugged in any side with no mirror effects.

[t-8ch]

uf2-split-left or uf2-split-right for each side

This is what I would like to avoid personally.
It was easier to solder a cable once than having to remember to flash the correct image every time.

[7oo1er]

Got it.

I removed -bl uf2-split-... key and flashed both sides with a same file. Both sides are right side now, can type 7890 on both with any side USB connected. Funny. And LED colors are same/mirrored.

I had errors with right encoder change volume, with a PGDN same time, was searching errors with (maybe) wrong encoder side recognition.