1 What: /sys/bus/iio/devices/iio:devic 1 What: /sys/bus/iio/devices/iio:deviceX/in_altvoltageY_invert
2 Date: October 2016 2 Date: October 2016
3 KernelVersion: 4.9 3 KernelVersion: 4.9
4 Contact: Peter Rosin <peda@axentia.se> 4 Contact: Peter Rosin <peda@axentia.se>
5 Description: 5 Description:
6 The DAC is used to find the pe 6 The DAC is used to find the peak level of an alternating
7 voltage input signal by a bina 7 voltage input signal by a binary search using the output
8 of a comparator wired to an in 8 of a comparator wired to an interrupt pin. Like so::
9 9
10 _ 10 _
11 | \ 11 | \
12 input +------>-------|+ \ 12 input +------>-------|+ \
13 | 13 | \
14 .-------. | 14 .-------. | }---.
15 | | | 15 | | | / |
16 | dac|-->--|- / 16 | dac|-->--|- / |
17 | | |_/ 17 | | |_/ |
18 | | 18 | | |
19 | | 19 | | |
20 | irq|------<-- 20 | irq|------<-------'
21 | | 21 | |
22 '-------' 22 '-------'
23 23
24 The boolean invert attribute ( 24 The boolean invert attribute (0/1) should be set when the
25 input signal is centered aroun 25 input signal is centered around the maximum value of the
26 dac instead of zero. The envel 26 dac instead of zero. The envelope detector will search
27 from below in this case and wi 27 from below in this case and will also invert the result.
28 28
29 The edge/level of the interrup 29 The edge/level of the interrupt is also switched to its
30 opposite value. 30 opposite value.
31 31
32 What: /sys/bus/iio/devices/iio:devic 32 What: /sys/bus/iio/devices/iio:deviceX/in_altvoltageY_compare_interval
33 Date: October 2016 33 Date: October 2016
34 KernelVersion: 4.9 34 KernelVersion: 4.9
35 Contact: Peter Rosin <peda@axentia.se> 35 Contact: Peter Rosin <peda@axentia.se>
36 Description: 36 Description:
37 Number of milliseconds to wait 37 Number of milliseconds to wait for the comparator in each
38 step of the binary search for 38 step of the binary search for the input peak level. Needs
39 to relate to the frequency of 39 to relate to the frequency of the input signal.
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.