1.. _fdc2x1x:
2
3FDC2X1X: Capacitance-to-Digital Converter
4#########################################
5
6Overview
7********
8
9This sample application periodically reads frequency and capacitance data from the
10FDC2X1X sensor in polling mode or optionally with data ready trigger. It is able
11to read the 12-Bit and 28-Bit, as well as the 2-Channel and 4-Channel versions
12(FDC2112, FDC2114, FDC2212, FDC2214). The 4-channel versions are chosen through
13devicetree properties. The default in this sample is the 2-channel version.
14
15Capacitive sensing is a low-power, low-cost, high-resolution contactless sensing
16technique that can be applied to a variety of applications ranging from proximity
17detection and gesture recognition to remote liquid level sensing. The sensor in
18a capacitive sensing system is any metal or conductor, allowing for low cost and
19highly flexible system design.
20The main challenge limiting sensitivity in capacitive sensing applications is
21noise susceptibility of the sensors. With the FDC2x1x innovative EMI resistant
22architecture, performance can be maintained even in presence of high-noise environments.
23
24
25Wiring
26*******
27
28This sample uses the FDC2X1X sensor controlled using the I2C interface.
29Connect supply **VDD** and **GND**. The supply voltage can be in
30the 2.7V to 3.6V range.
31
32Connect **SD** to a GPIO to control the Shutdown Mode.
33
34Connect Interface: **SDA**, **SCL** and optionally connect **INTB** to a
35interrupt capable GPIO.
36
37For detailed description refer to the `FDC2X1X datasheet`_
38at pages 4-5.
39
40
41Building and Running
42********************
43
44This sample outputs sensor data to the console and can be read by any serial
45console program. It should work with any platform featuring a I2C interface.
46The platform in use requires a custom devicetree overlay.
47In this example the :ref:`nrf9160dk_nrf9160` board is used. The devicetree
48overlay of this board provides example settings for evaluation, which
49you can use as a reference for other platforms.
50
51.. zephyr-app-commands::
52   :zephyr-app: samples/sensor/fdc2x1x
53   :board: nrf9160dk_nrf9160
54   :goals: build flash
55   :compact:
56
57Sample Output: 2-Channel, 28-Bit (FDC2212)
58==========================================
59
60.. code-block:: console
61
62        ch0: 5.318888 MHz ch1: 5.150293 MHz
63        ch0: 49.742308 pF ch1: 53.052260 pF
64
65        ch0: 5.318819 MHz ch1: 5.150307 MHz
66        ch0: 49.743612 pF ch1: 53.051964 pF
67
68        ch0: 5.318822 MHz ch1: 5.150200 MHz
69        ch0: 49.743548 pF ch1: 53.054176 pF
70
71        ch0: 5.318752 MHz ch1: 5.150265 MHz
72        ch0: 49.744860 pF ch1: 53.052828 pF
73
74        <repeats endlessly>
75
76
77Sample Output: 4-Channel, 12-Bit (FDC2114)
78==========================================
79
80.. code-block:: console
81
82        ch0: 4.966171 MHz ch1: 4.946465 MHz ch2: 4.985879 MHz ch3: 4.907051 MHz
83        ch0: 57.059016 pF ch1: 57.514568 pF ch2: 56.608844 pF ch3: 58.442204 pF
84
85        ch0: 4.966171 MHz ch1: 4.946465 MHz ch2: 4.985879 MHz ch3: 4.907051 MHz
86        ch0: 57.059016 pF ch1: 57.514568 pF ch2: 56.608844 pF ch3: 58.442204 pF
87
88        ch0: 4.966171 MHz ch1: 4.946465 MHz ch2: 4.985879 MHz ch3: 4.907051 MHz
89        ch0: 57.059016 pF ch1: 57.514568 pF ch2: 56.608844 pF ch3: 58.442204 pF
90
91        ch0: 4.966171 MHz ch1: 4.946465 MHz ch2: 4.985879 MHz ch3: 4.907051 MHz
92        ch0: 57.059016 pF ch1: 57.514568 pF ch2: 56.608844 pF ch3: 58.442204 pF
93
94        <repeats endlessly>
95
96
97References
98**********
99
100FDC2X1X Datasheet and Product Info:
101 https://www.ti.com/product/FDC2114
102
103.. _FDC2X1X datasheet: https://www.ti.com/lit/gpn/fdc2114
104