
Courtesy of Jim German of Motocube.
Using the Sensor Building Kit for NXT with PCF8574 IC, the SN754410 from Texas Instruments and some fancy wiring, Jim was able to control a Pneumatic Valve from his MINDSTORMS NXT.
While Jim mentions that this design could be improved (it requires a 24v power supply for starters) it is a good proof of concept. I can see a new range of home-grown pneumatic robots taking over the world... or the living room.
The full writeup is found here: Pneumatic Valves via Motocube