Goal: Create a board that will allow me to use standard radio CAT controls with my Alinco DX-SR8 radio.
Expanding on work done by Josh Myer  I intend to tap into the head unit cable, intercept it with a Atmel or Microchip PIC and insert my own commands to control the radio. Josh was able to capture and decode the serial commands being send between the head unit and the radio. I’ll use that to translate CAT commands from Ham Radio Deluxe or a similar piece of software into the Alinco serial commands. Additionally, this board will likely also be my digital interface and audio in/out.
Update 2017-05-29: First sketch of the circuit. We haven’t connected speaker and mic yet until we determine the best way to switch the audio. Also, the RX/TX pins may move once I review the USB specs on the ATx chip.