RC522 RFID¶
Component/Hub¶
The rc522 component allows you to use RC522 RFID controllers
(datasheet, Ali Express)
with ESPHome. This component is a global hub that establishes the connection to the RC522 via either SPI or
I²C and outputs its data. Using the RC522 binary sensors you can then
create individual binary sensors that track if an RFID tag is currently detected by the RC522.
See Setting Up Tags for information on how to setup individual binary sensors for this component.
The RC522 supports SPI, I²C and UART communication protocols, ESPHome can use either SPI or I²C.
If you have a module like the image above, it can only be used in SPI mode (unless hacked) and you need to have an SPI bus in your configuration with both the miso_pin and mosi_pin set.
If you have a RC522 which communicates via I²C like in the M5 Stack then you need to have an I²C bus configured.
SPI Option¶
spi:
rc522_spi:
cs_pin: GPIO15
binary_sensor:
- platform: rc522
uid: 74-10-37-94
name: "RC522 RFID Tag"
I²C Option¶
i2c:
rc522_i2c:
cs_pin: GPIO2
binary_sensor:
- platform: rc522
uid: 74-10-37-94
name: "RC522 RFID Tag"
Configuration variables:¶
reset_pin (Optional, Pin Schema): The pin connected to the RST line. Some tests shows the RC522 working okay without this.
update_interval (Optional, Time): The duration of each scan on the RC522. 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, Automation): An automation to perform when a tag is read. See on_tag.
id (Optional, ID): Manually specify the ID for this component.
SPI Only:¶
cs_pin (Required, Pin Schema): The pin on the ESP that the chip select line is connected to.
spi_id (Optional, ID): Manually specify the ID of the SPI Component if you want to use multiple SPI buses.
I²C Only:¶
address (Optional, int): Manually specify the I²C address of the sensor. Defaults to
0x28.i2c_id (Optional, ID): Manually specify the ID of the I²C Component if you want to use multiple I²C buses.
on_tag¶
This automation will be triggered when the RC522 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 rc522/tag.
rc522_spi: # or rc522_i2c
# ...
on_tag:
then:
- mqtt.publish:
topic: rc522/tag
payload: !lambda 'return x;'
A tag scanned event can also be sent to the Home Assistant tag component using homeassistant.tag_scanned Action.
rc522_spi: # or rc522_i2c
# ...
on_tag:
then:
- homeassistant.tag_scanned: !lambda 'return x;'
RFID Tag¶
The rc522 binary sensor platform lets you track if an RFID tag with a given
unique id (uid) is currently being detected by the RC522 or not.
# Example configuration entry
spi:
clk_pin: D0
miso_pin: D1
mosi_pin: D2
rc522_spi: # or rc522_i2c
cs_pin: D3
update_interval: 1s
binary_sensor:
- platform: rc522
uid: 74-10-37-94
name: "RC522 RFID Tag"
Configuration variables:¶
uid (Required, string): The unique ID of the 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, ID): Manually specify the ID used for code generation.
All other options from Binary Sensor.
Setting Up Tags¶
To set up binary sensors for specific RFID tags you first have to know their unique IDs. To obtain this id, first set up a simple RC522 configuration without any binary sensors like above.
When your code is running and you approach the RC522 with an RFID Tag, you should see a message like this:
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.