This is a simple HOTAS flight stick for Sparkfun Pro Micro boards (and clones) it uses the excellent NicoHood Gamepad API as the core https://github.com/NicoHood/HID as well as leveraging the SPI library for efficiently reading the shift registers. The code is pretty rough but is functional and it's fast enough for real gameplay, I have plans to integrate a better ADC in the future in the form of the Adafruit ADS1115 16bit, 4 channel ADC.
Schematics and board files are in CADsoft Eagle format.
Additional info on this HOTAS can be found on my Youtube channel: https://www.youtube.com/user/Atrixium