Stage of our geocache Qtouch
Build for our geocache GC50QG0.
http://coord.info/GC50QG0
You have to input a sequence and the microcontroller measures the capacity of each botton. If you input the right sequence you get a new one for the next stage. Code is written in C. Electronics are self made with Atmega 328p. Powered by 3xAA batteries. Enough power for one year. It is powered on by placing a magnet inside of the triangle. The magnet is hidden inside of a bug.