The KAP140 is an Autopilot System for use in aircraft. It was produced by Honeywell under the BendixKing brand, you can read more about it at: http://www.bendixking.com/Products/Discontinued/KAP-140
I wanted to use the FSBUS protocol to create a KAP140 in hardware/firmware for Microsoft Flight Simulator, this would let me use real knobs, switches and displays to give a fuller simulation and a much easier interface than clicking a mouse on a PC.
This repository contains the firmware that runs on an ATMel ATMEGA644 microcontroller. It connects to MS FlightSim over a serial connection.