ProjectTopics

color to sound: https://scienceland.wikispaces.com/file/view/MarciaRojasPoster.pdf

heart rate monitor: https://www.sparkfun.com/products/11574

instrument/guitar tuner: http://www.instructables.com/id/Arduino-Guitar-Tuner/?ALLSTEPS

sound changes with finger movements (w/ flex sensor): https://www.sparkfun.com/products/10264

temperature to sound: https://learn.sparkfun.com/tutorials/mlx90614-ir-thermometer-hookup-guide?_ga=1.191276713.242202950.1447447031

Homemade guitar: http://www.wikihow.com/Make-a-Rubber-Band-Guitar

Smart alarm clock: make an alarm clock with a force sensor which you could put under your pillow.  When the alarm goes off, it keeps ringing until the force sensor senses that your head is no longer on the pillow. 

Security system: ring alarm if door is opened, vibrations in the room, or moving objects. (eg. https://www.sparkfun.com/products/10293, etc.)

Clapper light: turn on a light with a clap (http://www.instructables.com/id/The-Viciously-Simple-Clap-ON-Clap-OFF-Circuit-For-/)

Make classic game of pong with arduino: http://www.makeuseof.com/tag/how-to-recreate-the-classic-pong-game-using-arduino/