We worked on a version of thermal fishing bob described here: [http://publiclab.org/wiki/thermal-fishing-bob](http://publiclab.org/wiki/thermal-fishing-bob) We found there were problems with the circuit diagram shown in this wiki page. This version uses a 10K Thermistor from Ada Fruit: [http://www.adafruit.com/products/372](http://www.adafruit.com/products/372) It comes with a 1% 10K resistor which you can use as calibration or for a resistor divider Additional parts: * 1 [common-anode RGB LED](http://www.sparkfun.com/products/10820) * wire * [a breadboard](http://www.sparkfun.com/products/7916) or circuit board & soldering eqmt. * [Arduino](http://arduino.cc) * 9v battery and holder Here is our first draft of the circuit board: [![Thermal_Fishing_Bob.jpg](https://i.publiclab.org/system/images/photos/000/001/738/medium/Thermal_Fishing_Bob.jpg)](https://i.publiclab.org/system/images/photos/000/001/738/original/Thermal_Fishing_Bob.jpg) Following the excellent [Ada Fruit instructions](http://learn.adafruit.com/thermistor/using-a-thermistor) changed the board to stabilize the voltage through the circuit: [![Screen_Shot_2013-10-08_at_3.04.17_PM.png](https://i.publiclab.org/system/images/photos/000/001/813/medium/Screen_Shot_2013-10-08_at_3.04.17_PM.png)](https://i.publiclab.org/system/images/photos/000/001/813/original/Screen_Shot_2013-10-08_at_3.04.17_PM.png) We had some successful tests: [![2013-10-05_20.46.08.jpg](https://i.publiclab.org/system/images/photos/000/001/779/medium/2013-10-05_20.46.08.jpg)](https://i.publiclab.org/system/images/photos/000/001/779/original/2013-10-05_20.46.08.jpg) [![IMAG2366.jpg](https://i.publiclab.org/system/images/photos/000/001/793/medium/IMAG2366.jpg)](https://i.publiclab.org/system/images/photos/000/001/793/original/IMAG2366.jpg) The circuit inside its repurposed Kool-Aid enclosure. [![IMAG2367.jpg](https://i.publiclab.org/system/images/photos/000/001/794/medium/IMAG2367.jpg)](https://i.publiclab.org/system/images/photos/000/001/794/original/IMAG2367.jpg) We stabilized it with styrofoam cups. [![IMAG2370.jpg](https://i.publiclab.org/system/images/photos/000/001/795/medium/IMAG2370.jpg)](https://i.publiclab.org/system/images/photos/000/001/795/original/IMAG2370.jpg) And deployed it in the bathtub.