With the candy machine you can draw three different types of candy and insert three different types of coins. Therefore the machine consist of two sections a “coin-section” handling the coins and a “spiral-section” that handles the candy. This combined with the fact that the machine uses 4 light sensors, 4 touch sensors and 4 motors made it necessary to use two RCX’s. The two programs are made in NQC where communication between multiple RCX’s is pretty straightforward. Since the machine uses 8 sensors I had to make a sensor expander to overcome the problem with only 3 sensor inputs on each RCX. I found instruction for the sensor expander at Michael Gasperi’s homepage.