Pieced together from the PID library and a tutorial on thermistors: http://arduino.cc/playground/Code/PIDLibraryAdaptiveTuningsExample http://arduino.cc/playground/Code/PIDLibrary http://arduino.cc/playground/ComponentLib/Thermistor2 Setup: Download the library from here: https://github.com/br3ttb/Arduino-PID-Library/zipball/master and move the PID_v1 to your arduino's /libraries directory Select your board type from the arduino IDE Burn it to your 'duino Parts List: - 1x large styrofoam box with one open end of dimensions WxH - 1x lasercut plexiglass front plate of dimensions WxH (from plate.svg) - 4x lasercut plexiglass petri dish mounting plates - 1x peltier cooler - 2x heat sinks - 2x fans - nuts + bolts - 1x hinge - 1x arduino - 1x 2kohm thermistors - 1x 2kohm resistors