mirror of
https://github.com/esphome/esphome-docs.git
synced 2024-11-16 10:55:21 +01:00
87 lines
2.9 KiB
ReStructuredText
87 lines
2.9 KiB
ReStructuredText
HX711 Load Cell Amplifier
|
|
=========================
|
|
|
|
.. seo::
|
|
:description: Instructions for setting up HX711 load cell amplifiers with ESPHome
|
|
:image: hx711.png
|
|
:keywords: HX711
|
|
|
|
The ``hx711`` sensor platform allows you to use your HX711
|
|
load cell amplifier
|
|
(`datasheet <https://www.mouser.com/ds/2/813/hx711_english-1022875.pdf>`__, `Sparkfun`_) with ESPHome
|
|
|
|
.. figure:: images/hx711-full.jpg
|
|
:align: center
|
|
:target: `Sparkfun`_
|
|
:width: 60.0%
|
|
|
|
HX711 Load Cell Amplifier. Image by `Sparkfun`_ licensed and re-distributed under `CC BY 2.0 <https://creativecommons.org/licenses/by/2.0/>`__.
|
|
|
|
.. _Sparkfun: https://www.sparkfun.com/products/13879
|
|
|
|
Connect ``GND`` to ``GND``, ``VCC`` to ``3.3V`` and the other three ``MISO`` (or ``SO`` for short),
|
|
``CS`` and ``CLOCK`` (or ``SCK``) to free GPIO pins.
|
|
|
|
.. code-block:: yaml
|
|
|
|
# Example configuration entry
|
|
sensor:
|
|
- platform: hx711
|
|
name: "HX711 Value"
|
|
dout_pin: D0
|
|
clk_pin: D1
|
|
gain: 128
|
|
update_interval: 60s
|
|
|
|
Configuration variables:
|
|
------------------------
|
|
|
|
- **name** (**Required**, string): The name for the load cell sensor.
|
|
- **dout_pin** (**Required**, :ref:`Pin Schema <config-pin_schema>`): The DOUT (or DAT) pin.
|
|
- **clk_pin** (**Required**, :ref:`Pin Schema <config-pin_schema>`): The CLK pin.
|
|
- **update_interval** (*Optional*, :ref:`config-time`): The interval to check the sensor. Defaults to ``60s``.
|
|
|
|
- **id** (*Optional*, :ref:`config-id`): Manually specify the ID used for code generation.
|
|
- All other options from :ref:`Sensor <config-sensor>`.
|
|
|
|
|
|
Converting Units
|
|
----------------
|
|
|
|
As the HX711 does not have any calibration data, you have to convert the measurement to units yourself.
|
|
To calibrate the sensor:
|
|
|
|
1. Place nothing or a known mass on the sensor, for example ``0kg``
|
|
2. Wait for the data to arrive in the logs and write down the value. For example ``120``.
|
|
3. Place another (different) known mass on the sensor, for example ``1kg``
|
|
4. Again wait for the data to arrive and note the value, for example ``810``.
|
|
|
|
Once you've done those steps, you can use the ``map`` function to map the incoming value to the calibrated one:
|
|
|
|
.. code-block:: yaml
|
|
|
|
# Example configuration entry
|
|
sensor:
|
|
- platform: hx711
|
|
# ... Other HX711 options
|
|
filters:
|
|
- lambda: |-
|
|
auto first_mass = 0.0; // first known mass was 0kg
|
|
auto first_value = 120.0; // value for the first known mass was 120
|
|
auto second_mass = 1.0; // second mass was 1kg
|
|
auto second_value = 810.0; // second value was 810
|
|
|
|
return map(x, first_value, second_value, first_mass, second_mass);
|
|
unit_of_measurement: kg
|
|
|
|
Replace the masses and values ``120.0``, ``810.0``, etc with your values.
|
|
|
|
See Also
|
|
--------
|
|
|
|
- :ref:`sensor-filters`
|
|
- :doc:`adc`
|
|
- :apiref:`sensor/hx711.h`
|
|
- `HX711 Library <https://github.com/bogde/HX711>`__ by `@bogde <https://github.com/bogde>`__
|
|
- :ghedit:`Edit`
|