I recently purchased the DF rover from robotshop, which comes with a duemilanove microcontroller, and a phidgets IR motion detector (P/N 1111). I have a basic understanding of how to use the arduino but have no idea how to program it to receive data from the IR sensor. An example sketch would be great.
The place where J4 is at, a light-sensitive resistor is placed (R28, with some Chinese scribbles). I bet it's just a heavily doped semiconductor, which changes resistance at different ambient light intensity. You need to connect the J4 so your analog input A0 will measure a value corresponding to ambient light, through R6. Say if the semiconductor R28 is at 10KOhm, basically environment is light, then your A0 reading is 2.5V. If there's no light, R28 is possibly 100KOhm or more so the A0 reads about 4.5V or more. This is not meant to be accurate but you should get your own emperical value of what reading is bright enough and what is too dark.
The other sensor, temperasure sensor is that LM35 on the side. A1 will get its value. just google LM35 for its spec. probably 0.01V/degC.
http://www.national.com/mpf/LM/LM35.html#Overview
Those are the sensors mentioned, as far as I can tell from the diagram.
If you want to know where those sensors are at, they are to the left side of the blue connector on the right, one is black cylinder (with one side cut off, like a transistor if you know what transistors look like). That's your temperature sensor, the other one with a clear top and a snake shape wire under the clear top is your light sensor. Good luck.
You're made of money. I'd be able to get a bunch of toys if I had that $90 or even more. Come report back with some videos, would you?