Klipper for Ender 3 S1 Pro - Raspberry Pi Zero 2w

I got the inspiration from AFGator58, but I wanted to mount everything in the base of the Ender 3 S1 Pro. So I found some designs, modified them, and got everything working correctly.

This is a good guide that walks you through the process to convert to Klipper, just make sure that when you get to the make menuconfig step, set USART6 PA2/PA3 for communication interface.

Note that AFGator58's wiring is correct, except I did not connect power to the GPIO of the Raspberry Pi Zero 2w. Instead, I provided power to the Pi Zero from an LM2596 dual USB buck converter, which pulls power from the main power supply.. So I only have three wires connecting from the GPIO to the touch-screen cable: Rx, Tx, and Ground. I did a lot of online research and found this to be the best. I also soldered the wires directly to the Pi Zero board (without header), as using Dupont cables connected to the GPIO header was too tall and the bottom cover would hit.

I also used USB panel-mount extension cable to allow using an accelerometer (KUSBA). I modified a display mount for this; I may update this to add an HDMI panel-mount cable as well, to allow connection of a display to the Pi Zero.

When creating the .bin file to flash the main board, make sure to set USART6 PA2/PA3 for communication interface.

When I first started looking at converting to Klipper, I reached out to AFGator to get detailed info on the UART connection, this was his response:

"Here is some helpful information, Follow the two linked guides:

There is quite a bit of config in order to setup:
 https://github.com/Harrypulvirenti/KlipperConfigS1/wiki/UART-Connection
Helpful Thread
 https://www.reddit.com/r/Ender3S1/comments/18to80p/klipper_serial_communication_via_touchscreen/

You need to enable the serial interface configure your Pi Zero 2 W to disable bluetooth or other services communicating through serial0. 
In the latest klipper version for PiZ2 (on pi imager, I'm unsure about KIAUH) most of the other serial config is already done so you dont need to change too much. Just use it for trouble shooting in case your mcu is not connecting, but follow the thread and you should get somewhere. 

This thread helped me quite a bit with the wiring, however my klipper.bin make wouldn't work with any of the selected USART Pins [They used USART1 PA10/PA9 or USART1 PB7/PB6]
Most STM32401 boards have a display RX/TX link to USART6 PA2/PA3 so those worked for me. 

The wiring in the images is correct, however I am having some trouble with the models GPIO cutout lining up & clearance. but yeah powering and communicating through the display cable is such an insane mod for S1Pro Klipper. You'll free up USB ports and it will look so much neater. Good luck."