After blow up few ioio cards by connecting power cable wrong way, i decides add some reverse voltage protection. i have used two 1N4007 diodes in VIN line.
First diode is connected between VIN and GND, cathode goes VIN and anode to GND. This should burn fuse in powersupply if reverse voltage is used.
Second diode is placed to the power wire. Green wire goes VIN pin.
