HA : ESPHome : RFID Reader

 Previously, I installed ESPHome with a simple indicator, showing whether a GPIO pin was hi or lo.
Many devices we use with Home Assistant (HA) have specific home automation interfaces.  ESPHome extends HA functionality by providing an interfaces for many more sensor components which can measure the environment somehow.  ESPHome provides the capability to interact with RFID readers and cards / tags.

I purchased three RC522 readers on Ebay and they turned out to be very simple to setup.

I am using a ESP32-VROOM-32 as my ESPHome server device and it communicates with RC522 using SPI.  ESPHome is configured using HA.  Firstly we define the pins to be used for spi.  We can then add the pin required for RC522.  Using the ESPHome UI we tell HA to install this configuration and it spends a couple of minutes compiling an image and downloading it wirelessly to the ESP32.  I connected the 4 data pins plus 3V3 and GND from the ESP22 to the RC522 and ESPHome showed that it was communicating 😀😀😀

 The next stage is to present a keyring-tag or card to the reader.  When you do this the ESPHome console log shows the id.  You can add each tag uid as a binary sensor within ESPHome and then look at them on a dashboard.

Once we have binary sensors we can set up a HA automation which is triggered whenever the binary sensor state is changed.  My  initial experiment instructs the Google Nest Mini speaker to inform me when Tag 1 is presented to the reader and when it is removed.

There are ways we could use the cards.  I could present a card to the reader when I enter or leave the room and everything could be setup for me.  Baby Harry could have a variety of cards to do things when he wants them. 
I did check whether NFC on my phone is acceptable to the reader.  It does register and send a tag id to HA, but the tag is different each time, possibly as it uses more sophisticated security, so it isn't much use to me.