Pi Zero HID gadget

Setup according to https://github.com/girst/hardpass-sendHID

Test:

echo -ne "\x00\x00\x00\x38\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" > /dev/hidg0
pass test/dummy | ./scan /dev/hidg0 2 2

GY-521 accelerometer

http://blog.bitify.co.uk/2013/11/reading-data-from-mpu-6050-on-raspberry.html