The second prototype is ready. I still have only a vague idea how to mount OLED display and joysticks. At the moment they are fastened with brass M3 screws.

I have also made small notches on the back side so that potentiometers and switches won't rotate.

I decided not to use thumb knobs that came with the joysticks. I drilled 2mm holes in wooden pegs and I put them on the joysticks' shafts. This way I have better control and precision over the joystick movement.

The tests revealed some flaws in the software that need to be fixed:

• I wait for virtual USB serial port to be ready and because of this the joystick simulation won't work until some software opens COM port on PC side. After that the port can be closed and it works fine
• during mounting process I exchanged RCS/SAS switches and LEDs, it's easier to fix this is software
• I didn't read the docs with full attention and I pass values -127 to 127 as X/Y/Z axis rotation instead of 0-359 degrees
• I need to have a "status report" command so that modules report status of all potentiometers and switches on request, not only when they change

The hardware needs some further work too:

• I need to change the scale of analog voltmeters from 0-5V into 0-100% power and 0-5G force
• I have to add remaining 4 red and 2 green LEDs
• someone on Kerbal forums had a nice idea to add flicker whenever power level is low, this doubles the function of LOW POWER indicator, but may be a nice touch
• how to nicely mount joysticks?
• how to nicely mount OLED display?
• how to make labels?
  • should I keep the panel white and just print them on paper?
  • should I spray-paint the panel silver or gray? But then - how to make labels? I can't just print them on paper anymore
  • maybe I should order a whole 20x30cm panel printed on adhesive foil

Of course I also have to rewrite Python interface between serial commands coming out of the panel and kRPC.