88 lines
2.7 KiB
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88 lines
2.7 KiB
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HX711 Load Cell Amplifier
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=========================
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.. seo::
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:description: Instructions for setting up HX711 load cell amplifiers with ESPHome
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:image: hx711.jpg
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:keywords: HX711
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The ``hx711`` sensor platform allows you to use your HX711
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load cell amplifier
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(`datasheet <https://www.mouser.com/ds/2/813/hx711_english-1022875.pdf>`__, `SparkFun`_) with ESPHome
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.. figure:: images/hx711-full.jpg
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:align: center
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:target: `SparkFun`_
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:width: 60.0%
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HX711 Load Cell Amplifier. Image by `SparkFun`_ licensed and re-distributed under `CC BY 2.0 <https://creativecommons.org/licenses/by/2.0/>`__.
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.. _SparkFun: https://www.sparkfun.com/products/13879
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Connect ``GND`` to ``GND``, ``VCC`` to ``3.3V`` and the other two ``DOUT`` (or ``DT`` for short)
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and ``CLK`` (or ``SCK``) to free GPIO pins.
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.. code-block:: yaml
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# Example configuration entry
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sensor:
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- platform: hx711
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name: "HX711 Value"
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dout_pin: D0
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clk_pin: D1
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gain: 128
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update_interval: 60s
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Configuration variables:
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------------------------
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- **dout_pin** (**Required**, :ref:`Pin Schema <config-pin_schema>`): The DOUT (or DAT) pin.
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- **clk_pin** (**Required**, :ref:`Pin Schema <config-pin_schema>`): The CLK pin.
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- **gain** (*Optional*, enum): The gain. Implicitly selects the channel. Defaults to ``128``.
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- ``32`` (Channel B, gain 32)
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- ``64`` (Channel A, gain 64)
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- ``128`` (Channel A, gain 128)
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- **update_interval** (*Optional*, :ref:`config-time`): The interval to check the sensor. Defaults to ``60s``.
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- All other options from :ref:`Sensor <config-sensor>`.
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Converting Units
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----------------
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As the HX711 does not have any calibration data, you have to convert the measurement to units yourself.
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To calibrate the sensor:
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1. Place a zero load or a known mass on the sensor, for example ``0kg``
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2. Wait for the data to arrive in the logs and write down the value. For example ``120``.
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3. Place another (different) known mass on the sensor, for example ``1kg``
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4. Again wait for the data to arrive and note the value, for example ``810``.
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Once you've done those steps, you can use the ``calibrate_linear`` filter to map the incoming value
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to the calibrated one:
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.. code-block:: yaml
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# Example configuration entry
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sensor:
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- platform: hx711
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# ... Other HX711 options
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filters:
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- calibrate_linear:
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- 120 -> 0
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- 810 -> 1
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unit_of_measurement: kg
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Replace the masses and values ``120.0``, ``810.0``, etc with your values.
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See Also
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--------
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- :ref:`sensor-filters`
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- :doc:`adc`
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- :apiref:`hx711/hx711.h`
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- `HX711 Library <https://github.com/bogde/HX711>`__ by `@bogde <https://github.com/bogde>`__
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- :ghedit:`Edit`
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