Programming hitec D485 rc servo settings

[rtv]

I got HITEC D485HW digital servo for my project, but not a programmer to change settings in it.
Programmer DPC-11 or HFP-30 is not expensive, but I looked for a cheaper option.

I don't know how DPC-11 Universal Programming Interface for Hitec’s Programmable Servo is made
But it is using Silabs cp210x driver

Hitec HMI protocol is known for older servos, but it wasn't compatible with D-series servo.

After some probing and tinkering I got DPC-11 pc sofware to work with FTDI rs232 ttl adapter.
And as an extra feature found hidden menu in DPC-11 software. (thanks https://github.com/0xd4d/dnSpy)

Adapter interface is simple: 1 resistor to tx line and connect it to rx and then to servo input.
Program is using uart break command to pull tx line high (and rx) when reading data from servo.

Ft_prog program was used to invert tx and rx signals of the rs232r chip.(Don't forget to undo after use ) 

SiUSBXp.dll in program folder must be replaced with attached dll, which is wrapping Silabs USBXpress commands to FTDI D2XX.
This will propably only work with D-series servos.

Change settings at your own risk.
Motor of the servo is stronger than position potentiometers axle.  Don't ask how I know   

After looking at the protocol it is same as robotro.com servos have

Ft_prog:
https://www.ftdichip.com/Support/Utilities/FT_Prog_v3.6.88.402%20Installer.exe

DPC-11 pc sofware:
https://hitecrcd.com/uploads/DPC-11_Setup_20180214_V2.9.1.zip

 SiUSBXp.zip (18.75 kB - downloaded 120 times.)