esp-idf/docs/en/api-reference/peripherals/temp_sensor.rst
2022-01-06 10:14:54 +08:00

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Temperature Sensor
===================
.. only:: esp32s3
.. warning::
This feature is not supported in v4.4
Overview
--------
The {IDF_TARGET_NAME} has a built-in temperature sensor used to measure the chip's internal temperature, and hard to measure the environmental temperature accurately. Being built-in means that the temperature sensor should work on any {IDF_TARGET_NAME} regardless of what board the chip is embedded in. The temperature sensor module contains an 8-bit Sigma-Delta ADC and a temperature offset DAC.
The conversion relationship is the first columns of the table below. Among them, offset = 0 is the main measurement option, and other values are extended measurement options.
+--------+------------------------+------------------------+
| offset | measure range(Celsius) | measure error(Celsius) |
+========+========================+========================+
| -2 | 50 ~ 125 | < 3 |
+--------+------------------------+------------------------+
| -1 | 20 ~ 100 | < 2 |
+--------+------------------------+------------------------+
| 0 | -10 ~ 80 | < 1 |
+--------+------------------------+------------------------+
| 1 | -30 ~ 50 | < 2 |
+--------+------------------------+------------------------+
| 2 | -40 ~ 20 | < 3 |
+--------+------------------------+------------------------+
Driver Usage
------------
1. Initialize the temperature sensor by calling the function :cpp:func:`temp_sensor_set_config` and pass to it a :cpp:type:`temp_sensor_config_t` structure. The :cpp:type:`temp_sensor_config_t` structure should contain all the required parameters. See the example below.
.. code-block:: c
temp_sensor_config_t temp_sensor = {
.dac_offset = TSENS_DAC_L2,
.clk_div = 6,
};
temp_sensor_set_config(temp_sensor);
2. Start the temp_sensor by calling :cpp:func:'temp_sensor_start'. The temperature sensor will now measure the temperature.
3. To get the current temperature, take the example below as a reference, the value you get is in Celsius.
.. code-block:: c
float tsens_out;
temp_sensor_read_celsius(&tsens_out);
4. To stop the temperature sensor, please call :cpp:func:'temp_sensor_stop'.
.. note::
If you want dynamic reconfiguration, you need to stop the sensor first (temp_sensor_stop), set the new configuration (temp_sensor_set_config), then start the sensor again (temp_sensor_start).
Application Example
-------------------
Temperature sensor reading example: :example:`peripherals/temp_sensor`.
API Reference - Normal Temp Sensor
----------------------------------
.. include-build-file:: inc/temp_sensor.inc