Ok I ran that command and found that I only got key codes for event0. The n810 has event0-3 listed on mine, heres the codes I got for the keys I tried (all event0):
up: 103
right: 106
down: 108
left: 105
center key: 96
window switcher (top button next to display): 63
back (button under window switcher): 1
enter on keyboard: 28
menu key: 62

Let me know if you need any others.