Suppose you want to program a Hitec D-series digital servo, but you don't have Hitec's DPC-11 dongle. This guide describes how to use an FTDI serial adapter and an Arduino in place of Hitec's DPC-11 dongle, so you can use Hitec's GUI without having the physical DPC-11 dongle.
Motivation: This lets you reprogram the endpoints of your servo to be whatever you want. The range of motion can be increased to 180 degrees. Fail safe positions can be set, overload protection settings, dead band, speed, and more..
Let's get started.
Flash your arduino with the following code (just about any arduino will work):