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esphome-docs/components/binary_sensor/pn532.rst

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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>` or :ref:`I²C <i2c>` 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.
The PN532 can be configured to use either the SPI **or** I²C protocol for data communication.
You will need to switch the dip switches located on the module according to the table printed on the board.
SPI is usually switch 1 OFF and switch 2 ON and I²C is usually switch 1 ON and switch 2 OFF.
You will need to have the :ref:`SPI Bus <spi>` or the :ref:`I²C Bus <i2c>` configured depending on your choice.
Over SPI
--------
The ``pn532_spi`` 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.
.. code-block:: yaml
pn532_spi:
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`.
- **on_tag_removed** (*Optional*, :ref:`Automation <automation>`): An automation to perform
when a tag is removed. See :ref:`pn532-on_tag_removed`.
- **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:
Over I²C
--------
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:`I²C <i2c>` 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.
.. code-block:: yaml
pn532_i2c:
update_interval: 1s
binary_sensor:
- platform: pn532
uid: 74-10-37-94
name: "PN532 NFC Tag"
Configuration variables:
************************
- **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`.
- **i2c_id** (*Optional*, :ref:`config-id`): Manually specify the ID of the :ref:`I²C Component <i2c>` if you want
to use multiple I²C buses.
- **id** (*Optional*, :ref:`config-id`): Manually specify the ID for this component.
``on_tag`` Action
-----------------
This automation will be triggered when the PN532 module responds with a tag. This will only be triggered
if the tag is changed or goes away for one cycle of ``update_interval``.
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``.
See :ref:`pn532-ndef_reading` below for how to use the second ``tag`` parameter that is provided to this trigger.
.. code-block:: yaml
pn532_...:
# ...
on_tag:
then:
- mqtt.publish:
topic: pn532/tag
payload: !lambda 'return x;'
A tag scanned event can also be sent to the Home Assistant tag component
using :ref:`api-homeassistant_tag_scanned_action`.
.. code-block:: yaml
pn532_...:
# ...
on_tag:
then:
- homeassistant.tag_scanned: !lambda 'return x;'
Alternatively you could also send the value directly to Home Assistant via a
:doc:`template sensor </components/sensor/template>`.
.. code-block:: yaml
pn532_...:
# ...
on_tag:
then:
- text_sensor.template.publish:
id: rfid_tag
state: !lambda 'return x;'
text_sensor:
- platform: template
name: "RFID Tag"
id: rfid_tag
.. _pn532-on_tag_removed:
``on_tag_removed``
------------------
This automation will be triggered when the PN532 module responds with no tag. This will only be triggered
if the tag goes away for one cycle of ``update_interval``.
The parameter ``x`` this trigger provides is of type ``std::string`` and is the removed tag UID in the format
``74-10-37-94``. The configuration below will for example publish the removed tag ID on the MQTT topic ``pn532/tag_removed``.
.. code-block:: yaml
pn532:
# ...
on_tag_removed:
then:
- mqtt.publish:
topic: pn532/tag_removed
payload: !lambda 'return x;'
.. _pn532-tag:
``pn532`` Binary Sensor
-----------------------
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_spi:
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.
.. _pn532-ndef:
NDEF
====
The PN532 supports reading and writing NDEF formatted data into the cards.
.. _pn532-ndef_reading:
NDEF reading
------------
The following example will read an NFC tag that has been formatted and written using the Home Assistant Companion
App and send it to Home Assistant using the :ref:`api-homeassistant_tag_scanned_action`. The ``tag`` variable is
supplied to the ``on_tag`` trigger and any actions that run and can be used as below.
.. code-block:: yaml
pn532_...:
# ...
on_tag:
then:
- homeassistant.tag_scanned: !lambda |
if (!tag.has_ndef_message()) {
return x;
}
auto message = tag.get_ndef_message();
auto records = message->get_records();
for (auto &record : records) {
std::string payload = record->get_payload();
size_t pos = payload.find("https://www.home-assistant.io/tag/");
if (pos != std::string::npos) {
return payload.substr(pos + 34);
}
}
return x;
.. _pn532-ndef_writing:
NDEF Writing
------------
The following example can be used to write a (pseudo) random UUID to the tag in the same format as the
Home Assistant Companion App does.
.. code-block:: yaml
on_...
then:
- lambda: |-
static const char alphanum[] = "0123456789abcdef";
std::string uri = "https://www.home-assistant.io/tag/";
for (int i = 0; i < 8; i++)
uri += alphanum[random_uint32() % (sizeof(alphanum) - 1)];
uri += "-";
for (int j = 0; j < 3; j++) {
for (int i = 0; i < 4; i++)
uri += alphanum[random_uint32() % (sizeof(alphanum) - 1)];
uri += "-";
}
for (int i = 0; i < 12; i++)
uri += alphanum[random_uint32() % (sizeof(alphanum) - 1)];
auto message = new nfc::NdefMessage();
message->add_uri_record(uri);
ESP_LOGD("ndef", "Writing payload: %s", uri.c_str());
id(pn532_board).write_mode(message);
- wait_until:
not:
pn532.is_writing:
- logger.log: "Finished writing tag"
See Also
--------
- :doc:`index`
- :doc:`rdm6300`
- :doc:`rc522`
- :apiref:`pn532/pn532.h`
- :ghedit:`Edit`
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