README.rst
1.. zephyr:code-sample:: thermometer
2 :name: Thermometer
3 :relevant-api: sensor_interface
4
5 Get ambient temperature data from a temperature sensor and get alerts when temperature drifts
6 above a threshold. (polling & trigger mode).
7
8Overview
9********
10
11This sample application periodically measures the ambient temperature
12at 1Hz. The result is written to the console.
13
14Wiring
15*******
16
17VDD pin should be connected to 2.3V to 5.5V
18GND pin connected to 0V
19VOUT pin connected to the ADC input pin.
20
21.. _`MCP970X Sensor`: http://ww1.microchip.com/downloads/en/devicedoc/20001942g.pdf
22
23An overlay is provided for the nrf52840dk/nrf52840 board with the
24sensor connected to pin AIN7.
25
26Building and Running
27********************
28
29To build for the nrf52840dk/nrf52840 board use:
30
31.. zephyr-app-commands::
32 :zephyr-app: samples/sensor/thermometer
33 :board: nrf52840dk/nrf52840
34 :goals: build flash
35 :compact:
36
37
38To build for other boards and ambient temperature sensors, enable the sensor
39node that supports ``SENSOR_CHAN_AMBIENT_TEMP`` and use an overlay to create an
40alias named ``ambient-temp0`` to link to the node. See the overlay used for the
41``nrf52840dk/nrf52840`` board within this sample:
42``boards/nrf52840dk_nrf52840.overlay``
43
44
45Temperature Alert
46=================
47
48If the attached sensor supports alerts when the temperature drifts above or
49below a threshold, the sample will enable the sensor's trigger functionality.
50This will require the sensor's TRIGGER KConfig setting to be enabled. An
51example of this setup is provided for the ``frdm_k22f`` board, using
52``boards/frdm_k22f.conf``.
53
54Sample Output
55=============
56
57.. code-block:: console
58
59 *** Booting Zephyr OS build zephyr-v3.3.0-2354-gb4f4bd1f1c22 ***
60 Thermometer Example (arm)
61 Temperature device is 0x525c, name is tcn75a@48
62 Set temperature lower limit to 25.5°C
63 Set temperature upper limit to 26.5°C
64 Enabled sensor threshold triggers
65 Temperature is 25.0°C
66 Temperature is 25.0°C
67 Temperature is 25.0°C
68 Temperature is 25.0°C
69 Temperature is 25.5°C
70 Temperature above threshold: 26.5°C
71 Temperature is 26.5°C
72
