nice find hopefully this helps with the development
That's really neat. My best solution so far is connecting serially to an ATMega microcontroller. This solves both the limited IO as well as level conversion and it means that the RasPi can now deal with loads of 5v and 3v3 logic level signals.
I've also added a super cheap nokia 5110 LCD. These are insanely inexpensive ($5.80 plus free shipping worldwide from DX.com) and insanely simple to wire up and drive and it can be driven directly by the RasPi's 3v3 signals. This LCD is nice because it gives you 84 x 48 pixels to play with and uses only 5 GPIO pins (the same as my previous 5 LEDs). This means we can display text and simple bitmap graphics!
I shot a video of the LCD screen working yesterday on my phone but somehow the video got corrupted and you can only hear the audio. I'll try taking another video soon showing off the basic features so far.
This may already be linked in the thread somewhere but I saw this and thought of your project: http://www.astro-designs.com/page14.php
What is the PiXi-200?
The PiXi-200 is designed to expand the I/O capabilities of the Raspberry Pi and provide a low-cost means of introducing the user to the world of digital electronics and FPGA technology while at the same time give the 'Pi enthusiast' a little more to play with or even provide a basis for some product development.
Oh man, this is super exciting. Hopefully I can build up my soldering confidence enough to put one together eventually. Kudos to you for finding such cheap components and planning to make everything freely available, Jeff
what happened to this project? this is what i want.