Thermal coloured floating lanterns

Hack Details: Japan’s Toro Nagashi (floating lantern) festival is beautiful. If the color and flash rate of the lanterns depended on the temperature and conductivity of the water, we could do beautiful science with time exposures of the festival. The device should be designed to be small and inexpensive like ‘throwies’ so that a large number of lanterns could track current and temperature. These, of course should be retrieved if they are not biodegradable. https://s-media-cache-ak0.pinimg.com/564x/16/0d/16/160d16224a63bde697cd0b1dbb1cea72.jpg
What you need to make it happen? Arduino or AVR microcontroller Floating lantern materials (wood/bamboo and paper) thermistor or dallas semiconductor temperature chip red LED blue LED green LED (optional) battery power supply solderless breadboard wires, resistors transistor or driver chip to increase current to LEDs.
Name: Brian Nitz
Twitter/website: http://www.opensourcemechanic.com