1What:		/sys/bus/iio/devices/iio:deviceX/in_altvoltageY_invert
2Date:		October 2016
3KernelVersion:	4.9
4Contact:	Peter Rosin <peda@axentia.se>
5Description:
6		The DAC is used to find the peak level of an alternating
7		voltage input signal by a binary search using the output
8		of a comparator wired to an interrupt pin. Like so:
9		                           _
10		                          | \
11		     input +------>-------|+ \
12		                          |   \
13		            .-------.     |    }---.
14		            |       |     |   /    |
15		            |    dac|-->--|- /     |
16		            |       |     |_/      |
17		            |       |              |
18		            |       |              |
19		            |    irq|------<-------'
20		            |       |
21		            '-------'
22		The boolean invert attribute (0/1) should be set when the
23		input signal is centered around the maximum value of the
24		dac instead of zero. The envelope detector will search
25		from below in this case and will also invert the result.
26		The edge/level of the interrupt is also switched to its
27		opposite value.
28
29What:		/sys/bus/iio/devices/iio:deviceX/in_altvoltageY_compare_interval
30Date:		October 2016
31KernelVersion:	4.9
32Contact:	Peter Rosin <peda@axentia.se>
33Description:
34		Number of milliseconds to wait for the comparator in each
35		step of the binary search for the input peak level. Needs
36		to relate to the frequency of the input signal.
37