When you consider to use the analog input (AIN0 to AIN6), be careful!
On my board with kernel 3.8.13 I get (open lines AIN0 - 6, AIN7 connected to 3.3V * 1/2)
which first made me think these are digit values and the maximum input voltage may be higher than described (1.8 V).# cat /sys/devices/ocp.2/helper.14/AIN*
1799
1393
963
585
1794
1669
1530
1676
But instead these are values computed by the kernel driver. It converts the raw data to mV values, rounded as !!! integers !!! (not floats). (This also means 2.2 bits get lost!)
You can receive the raw data by
# cat /sys/bus/iio/devices/iio\:device0/in_voltage*_raw
4093
3197
2194
1324
4082
3736
3381
3816