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[adc] Change 11dB references to 12dB (#3837)

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Jesse Hills 2024-05-15 13:01:43 +12:00 committed by GitHub
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10
components/sensor/adc.rst
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@ -62,8 +62,8 @@ ESP32 Attenuation
-----------------
On the ESP32 the voltage measured with the ADC caps out at ~1.1V by default as the sensing range (attenuation of the ADC) is set to ``0db`` by default.
Measuring higher voltages requires setting ``attenuation`` to one of the following values: ``0db``, ``2.5db``, ``6db``, ``11db``.
There's more information `at the manufacturer's website <https://docs.espressif.com/projects/esp-idf/en/v4.4.2/esp32/api-reference/peripherals/adc.html#_CPPv425adc1_config_channel_atten14adc1_channel_t11adc_atten_t>`__.
Measuring higher voltages requires setting ``attenuation`` to one of the following values: ``0db``, ``2.5db``, ``6db``, ``12db``.
There's more information `at the manufacturer's website <https://docs.espressif.com/projects/esp-idf/en/v4.4.7/esp32/api-reference/peripherals/adc.html#_CPPv425adc1_config_channel_atten14adc1_channel_t11adc_atten_t>`__.
To simplify this, we provide the setting ``attenuation: auto`` for an automatic/seamless transition among scales. `Our implementation
<https://github.com/esphome/esphome/blob/dev/esphome/components/adc/adc_sensor.cpp>`__ combines all available ranges to allow the best resolution without having to compromise on a specific attenuation.
@ -117,7 +117,7 @@ For users that don't need a precise voltage reading, the "raw" output option all
- multiply: 0.00026862 # 1.1/4095, for attenuation 0db
- multiply: 0.00036630 # 1.5/4095, for attenuation 2.5db
- multiply: 0.00053724 # 2.2/4095, for attenuation 6db
- multiply: 0.00095238 # 3.9/4095, for attenuation 11db
- multiply: 0.00095238 # 3.9/4095, for attenuation 12db
# your existing filters would go here
Note we don't recommend this method as it will change between chips, and newer ESP32 modules have different ranges (i.e. 0-8191); it is better to use the new calibrated voltages and update any existing filters accordingly.
@ -188,7 +188,7 @@ You can only use as many ADC sensors as your device can support. The ESP8266 onl
Measuring battery voltage on the Firebeetle ESP32-E
---------------------------------------------------
This board has a internal voltage divider and the battery voltage can easily be measured like this using 11dB attenuation
This board has a internal voltage divider and the battery voltage can easily be measured like this using 12dB attenuation
on GPIO34.
.. code-block:: yaml
@ -198,7 +198,7 @@ on GPIO34.
pin: GPIO34
accuracy_decimals: 2
update_interval: 60s
attenuation: 11dB
attenuation: 12dB
filters:
- multiply: 2.0 # The voltage divider requires us to multiply by 2