Mobile reader tester

This is a test machine for mobile readers (like Squareup or PayPal Here).
It consists:

1. STM32VLDISCOVERY
2. mobile reader
3. phone
4. tamiya reductor from a toy
5. reeds with magnet
6. https://github.com/evsinev/stm32-servo-arm

Rack and Gear are based on http://www.thingiverse.com/thing:5505

Tester in action http://www.youtube.com/watch?v=9QPTB-jzgfo and http://www.youtube.com/watch?v=O_V5czH0LhM