This will work for logining in: https://smile.amazon.com/gp/product/B012FOV17O/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I've used these with Centipede code for updating Chromebooks. Look at the code here and should be able to adapt to your needs.

https://drive.google.com/file/d/1yrW_Amg-CWvNsHRUG1nJsl9dEX7JDtW-/view?usp=drive_web

Choosing Teensy was based on no reason really, just wanted to try it out. Any of the boards compatible with mmjoy2 would be fine. There are a good number of Arduino knock-offs as well. The processor to look for is the ATmega32U4 which the Teensy 2.0 and Arduino Pro Micro both use.

I considered using crimp on header pins going straight to the board at first. The disadvantage is that in a few instances you would need to connect multiple wires to the same pin such as with the VCC and GND pins. You may also have to share the CLK pin if there are multiple serial connections. Not saying it can't be done that way, it would definitely work using that method. I mostly wanted each component/cable to have it's own connector that I could label for future reference.

That is one of the advantages of the Leo Bodnar boards, they have extra terminals for VCC/GND next to each of the inputs.