Train set in a Suitcase

This is my N-Scale train in a phonograph box. It runs on an Arduino and Motor shield. I put a reed sensor on the tracks, and glued a small magnet underneath the locomotive. When the train passes the over pass, the tin-can bridge closes,  the locomotive slows down to a stop and whistles. The train whistle plays from a Radio Shack recorder module. The speaker is hidden inside the overpass. It creates an awesome illusion that the train is actually playing the whistle sound!  I put a relay in place of the play button. The recorder is powered through the motor shield. After the train whistles, the two light posts light up in a series of patterns. the tin-can slowly opens and the school rings rings. The train begins again passing through until it reaches the reed sensor and it repeats all over. The red button can be pressed at anytime to activate the whistle.

http://www.youtube.com/watch?v=VgM5Xotab2I