i was thinking. would the sensors on the mindstorm be any good for arduino? i know that http://cgi.ebay.co.uk/Lego-Mindstorm-8527-8547-NXT-2-0-Light-Sensor-55969-/230553994641?pt=UK_Construction_Toys_Kits&hash=item35ae16c591#ht_734wt_905 just outputs a number value to the bot.
all i think the light sensor has is an light resistor ( i think thats the name ) but more complex ones like the colour sensor have more exspesive sensors in. oh well at the moment im intefacing my old monopoly card reader thingy to use as a simple alarm
Lego NXT sensors are interfaced using the I2C bus. However they work off 3v3 and so require a voltage translator before connecting directly to the arduino. http://www.instructables.com/id/Simple-interfacing-Lego-Mindstorms-NXT-to-Arduino-/