diff --git a/components/sensor/binary_sensor_map.rst b/components/sensor/binary_sensor_map.rst
index 28a6c4212..82e4ccf49 100644
--- a/components/sensor/binary_sensor_map.rst
+++ b/components/sensor/binary_sensor_map.rst
@@ -5,19 +5,50 @@ Binary Sensor Map
:description: Instructions for setting up a Binary Sensor Map
:image: binary_sensor_map.jpg
-The ``binary_sensor_map`` sensor platform allows you to map :doc:`binary sensor `
-to values. When a given binary sensor is on, the value associated with it in this platform's configuration will be published.
+The ``binary_sensor_map`` sensor platform allows you to map multiple :doc:`binary sensor `
+to an individual value. Depending on the state of each binary sensor, its associated configured parameters, and this sensor's mapping type,
+the ``binary_sensor_map`` publishes a single numerical value.
-This sensor is **mostly used for touch** devices but could be used for any ``binary_sensor`` that publishes its ``ON`` or ``OFF`` state.
+Use this sensor to combine one or more binary sensors' ``ON`` or ``OFF`` states into a numerical value. Some possible use cases include
+touch devices and determining Bayesian probabilities for an event.
-Add your binary sensors as ``channels`` to the binary sensor map. The binary sensor map then publishes a value depending
-on the type of the binary sensor map and the values specified with each channel. The maximum amount of possible channels is 64.
+This platform supports three measurement types: ``BAYESIAN``, ``GROUP``, and ``SUM``.
+You need to specify your desired mapping with the ``type:`` configuration value.
-This platform currently supports two measurement types: ``GROUP`` and ``SUM``, and others might get added later.
-You need to specify which type of mapping you want with the ``type:`` configuration value:
+When using the ``BAYESIAN`` type, add your binary sensors as ``observations`` to the binary sensor map.
+If you use the ``GROUP`` or ``SUM`` type, add your binary sensors as ``channels``.
+The maximum amount of observations/channels supported is 64.
-- ``GROUP`` Each channel has its own value. The sensor publishes the average value of all active
- binary sensors.
+- ``BAYESIAN`` This type replicates Home Assistant's `Bayesian sensor `__. Based on the observation states, this sensor returns the Bayesian probability of a particular event occurring. The configured ``prior:`` probability is the likelihood that the Bayesian event is true, ignoring all external influences. Every observation has its own ``prob_given_true`` and ``prob_given_false`` parameters. The ``prob_given_true:`` value is the probability that the observation's binary sensor is ``ON`` when the Bayesian event is ``true``. The ``prob_given_false:`` value is the probability that the observation's binary sensor is ``ON`` when the Bayesian event is ``false``. Use an :doc:`/components/binary_sensor/analog_threshold` to convert this sensor's probability to a binary ``ON`` or ``OFF`` by setting an appropriate threshold.
+
+.. code-block:: yaml
+
+ # Example configuration entry
+ sensor:
+ - platform: binary_sensor_map
+ id: bayesian_prob
+ name: 'Bayesian Event Probability'
+ type: bayesian
+ prior: 0.4
+ observations:
+ - binary_sensor: binary_sensor_0
+ prob_given_true: 0.9
+ prob_given_false: 0.2
+ - binary_sensor: binary_sensor_1
+ prob_given_true: 0.6
+ prob_given_false: 0.1
+
+ binary_sensor:
+ # If the Bayesian probability is greater than 0.6,
+ # then predict the event is occuring
+ - platform: analog_threshold
+ name: "Bayesian Event Predicted State"
+ sensor_id: bayesian_prob
+ threshold: 0.6
+ # ...
+
+- ``GROUP`` Each channel has its own ``value``. The sensor publishes the average value of all active
+ binary sensors or ``NAN`` if no sensors are active.
.. code-block:: yaml
@@ -48,8 +79,8 @@ You need to specify which type of mapping you want with the ``type:`` configurat
id: touchkey0
# ...
-- ``SUM`` Each channel has its own value. The sensor publishes the sum of all active
- binary sensors values.
+- ``SUM`` Each channel has its own ``value``. The sensor publishes the sum of all the active
+ binary sensors values or ``0`` if no sensors are active.
.. code-block:: yaml
@@ -91,12 +122,19 @@ Configuration variables:
------------------------
- **name** (**Required**, string): The name of the sensor.
-- **type** (**Required**, string): The sensor type. Should be one of: ``GROUP``.
-- **channels** (**Required**): A list of channels that are mapped to certain values.
+- **type** (**Required**, string): The sensor type. Should be one of: ``BAYESIAN``, ``GROUP``, or ``SUM``.
+- **channels** (**Required for GROUP or SUM types**): A list of channels that are mapped to certain values.
- **binary_sensor** (**Required**): The id of the :doc:`binary sensor `
to add as a channel for this sensor.
- **value** (**Required**): The value this channel should report when its binary sensor is active.
+- **prior** (**Required for BAYESIAN type**, float between 0 and 1): The prior probability of the event.
+- **observations** (**Required for BAYESIAN type**): A list of observations that influence the Bayesian probability of the event.
+
+ - **binary_sensor** (**Required**): The id of the :doc:`binary sensor `
+ to add as an observation.
+ - **prob_given_true** (**Required**, float between 0 and 1): Assuming the event is true, the probability this observation is on.
+ - **prob_given_false** (**Required**, float between 0 and 1): Assuming the event is false, the probability this observation is on.
- All other options from :ref:`Sensor `.
@@ -104,6 +142,8 @@ See Also
--------
- :doc:`/components/binary_sensor/mpr121`
+- :doc:`/components/binary_sensor/analog_threshold`
- :ref:`sensor-filters`
- :apiref:`binary_sensor_map/binary_sensor_map.h`
+- `Bayesian sensor in Home Assistant `__
- :ghedit:`Edit`