teensy 3.0 & android pin brute forcing

so after picking up a usb rubber ducky from HAK5 at defcon, i wanted to see if i could replicate a pin brute force tool using a teensy for android phones. i love the usb rubber ducky, but i figure if i have arduino’s to spare, why not use them ?

here is what i have come up with

its pretty straight forward and tested on android 4.1 & 4.2. confirmed not working in android 4.2 though.