[GreenKeys] more interface software

[epvgk at limpoc.com]

Hi!

Since everyone else seems to be doing interface software/firmware lately
I thought I'd post my current efforts in the event it saves someone else
some effort. 

My goal was a stripped down alternative to HeavyMetal in Python without 
the UI or all the builtin commands.   Instead, I focused primarily on 
1) talking to other programs/computers via TCP, and 
2) commands as plugins to be executed on the host computer and their 
output sent to the tty. 

Mostly I wanted something to handle the half duplex / echo cancelling
stuff without the commands or other computers to have to deal with it.
It will politely stop talking if it detects someone else talking on the
loop and the "Break" key can be used to interrupt commands or output. 
So far it's the only related project that I feel does this part well.

Work in progress on github here: 
https://github.com/epvuc/loop-gateway

I'm running it on a raspberry pi zero with one of the usb-tty adapters
I was selling this past year. (should work with other interfaces too)

If it's of use to anyone else please feel free to take what you want, but
also feel free to contribute. 

eric