For what it's worth I have a android program that creates a Bluetooth to ssh bridge. The core code is working but it needs a bunch of UI work particularly around the Bluetooth connection.
I figured with a bridge to run LaddieAlpha on the server then I don't need to make the tablet a TPDD server. And your terminal is just whatever you use for ssh either ssh plus Linux shell or Cygwin. Adding wired USB serial support would be much easier. Just need to find time to finish it. Maybe you'll beat me to it. -- John.
