esphome-docs/components/binary_sensor/pn532.rst

PN532 NFC/RFID
==============

.. seo::
    :description: Instructions for setting up PN532 NFC tag readers and tags in ESPHome
    :image: pn532.jpg
    :keywords: PN532, NFC, RFID

.. _pn532-component:

Component/Hub
-------------

The ``pn532`` component allows you to use PN532 NFC/RFID controllers
(`datasheet <https://cdn-shop.adafruit.com/datasheets/pn532ds.pdf>`__, `Adafruit <https://www.adafruit.com/product/364>`__)
with ESPHome. This component is a global hub that establishes the connection to the PN532 via :ref:`SPI <spi>` and
outputs its data. Using the :ref:`PN532 binary sensors <pn532-tag>` you can then
create individual binary sensors that track if an NFC/RFID tag is currently detected by the PN532.

.. figure:: images/pn532-full.jpg
    :align: center
    :width: 60.0%

See :ref:`pn532-setting_up_tags` for information on how to setup individual binary sensors for this component.

As the communication with the PN532 is done using SPI for this integration, you need to set the two switches on
the board to the SPI mode (usually by setting the first one to OFF and the second one to ON). Additionally, you need
to have an :ref:`SPI bus <spi>` in your configuration with both the **miso_pin** and **mosi_pin** set.

.. code-block:: yaml

    # Example configuration entry
    spi:
      clk_pin: D0
      miso_pin: D1
      mosi_pin: D2

    pn532:
      cs_pin: D3
      update_interval: 1s

    binary_sensor:
      - platform: pn532
        uid: 74-10-37-94
        name: "PN532 NFC Tag"

Configuration variables:
************************

- **cs_pin** (**Required**, :ref:`Pin Schema <config-pin_schema>`): The pin on the ESP that the chip select line
  is connected to.
- **update_interval** (*Optional*, :ref:`config-time`): The duration of each scan on the PN532. This affects the
  duration that the individual binary sensors stay active when they're found.
  If a device is not found within this time window, it will be marked as not present. Defaults to 1s.
- **on_tag** (*Optional*, :ref:`Automation <automation>`): An automation to perform
  when a tag is read. See :ref:`pn532-on_tag`.
- **spi_id** (*Optional*, :ref:`config-id`): Manually specify the ID of the :ref:`SPI Component <spi>` if you want
  to use multiple SPI buses.
- **id** (*Optional*, :ref:`config-id`): Manually specify the ID for this component.

.. figure:: images/pn532-spi.jpg
    :align: center
    :width: 80.0%

    Example for hooking up the PN532 via SPI. Notice the position of the two switches on the right.

.. _pn532-on_tag:

``on_tag``
----------

This automation will be triggered when the PN532 module responds with a tag. Please note that this
can be called quite often (with an interval of ``update_interval``) as it's triggered repeatedly
if the tag is re-read many times.

The parameter ``x`` this trigger provides is of type ``std::string`` and is the tag UID in the format
``74-10-37-94``. The configuration below will for example publish the tag ID on the MQTT topic ``pn532/tag``.

.. code-block:: yaml

    pn532:
      # ...
      on_tag:
        then:
          - mqtt.publish:
              topic: pn532/tag
              payload: !lambda 'return x;'

.. _pn532-tag:

NFC/RFID Tag
------------

The ``pn532`` binary sensor platform lets you track if an NFC/RFID tag with a given
unique id (``uid``) is currently being detected by the PN532 or not.

.. code-block:: yaml

    # Example configuration entry
    spi:
      clk_pin: D0
      miso_pin: D1
      mosi_pin: D2

    pn532:
      cs_pin: D3
      update_interval: 1s

    binary_sensor:
      - platform: pn532
        uid: 74-10-37-94
        name: "PN532 NFC Tag"

Configuration variables:
************************

- **uid** (**Required**, string): The unique ID of the NFC/RFID tag. This is a hyphen-separated list
  of hexadecimal values. For example ``74-10-37-94``.
- **name** (**Required**, string): The name of the binary sensor.
- **id** (*Optional*, :ref:`config-id`): Manually specify the ID used for code generation.
- All other options from :ref:`Binary Sensor <config-binary_sensor>`.

.. _pn532-setting_up_tags:

Setting Up Tags
---------------

To set up binary sensors for specific NFC tags you first have to know their unique IDs. To obtain this
id, first set up a simple PN532 configuration without any binary sensors like above.

When your code is running and you approach the PN532 with an NFC Tag, you should see a message like this:

.. code::

    Found new tag '74-10-37-94'

Then copy this id and create a ``binary_sensor`` entry as in the configuration example. Repeat this process for
each tag.

See Also
--------

- :doc:`index`
- :doc:`rdm6300`
- :apiref:`pn532/pn532.h`
- :ghedit:`Edit`