Atari Electronic Projects

Any one creating any interesting but completely useless electronic projects with their Ataris?

I've been thinking about using my Atari to control a Big Trak (http://en.wikipedia.org/wiki/Big_Trak) using a couple of XBees (http://en.wikipedia.org/wiki/XBee).  There was a good article on controlling a Big Trak with a Radio Shack walkie-talkie in Byte magazine back in 1981:

“A Computer-Controlled Tank”

http://archive.org/stream/byte-magazine-1981-02/1981_02_BYTE_06-02_The_Computer_and_Voice_Synthesis#page/n45/mode/2up

I think it would be fun to control the Big Trak via the joystick port using some XBee radios.   

Here are some other links with some electronic projects which include the joystick and SIO port pin outs.

Atari Electronic Projects

Electronic Computer Projects for Commodore and Atari Personal Computers

http://www.atariarchives.org/ecp/

or

https://archive.org/details/Electronic_Computer_Projects_for_Commodore_and_Atari_Personnal_Computers

Electronic Projects For Your Commodore 64 and 128

https://archive.org/stream/Electronic_Projects_for_your_Commodore_64_and_128#page/n0/mode/2up

“Audio While You CLOAD”

http://www.atarimagazines.com/vbook/audiowhileyoucload.html

“Morse Code Receiver”

http://www.atarimagazines.com/v4n7/morsecode.html