This hand controller with OLED display plugs into OnStep's ST4 port and is able to fully operate an OnStep (Alpha branch) telescope controller. The Teensy3.2 micro-controller onboard runs the smart hand controller firmware (from OnStep's /src/addons/St4Serial directory.)
This is a preliminary design but basic testing has been done. There was a problem with the display connection on the PCB but this should be fixed. Still be careful to verify the schematic and PCB and your exact display to be sure the connections are correct.