This was originally written with inspiration from https://shawnrk.github.io/songblocks/ but without the overhead of a pi. I've since updated this code to run with the homie 2.0 spec homie-esp8266 code and published here.

You need the Arduino development environment for this. Plus the PM532 lib from https://github.com/Seeed-Studio/PN532. Apparently the Adafruit flavor of the PM532 lib does not support i2c on esp8266 so we have to jump through a couple hoops to make this go.

• NodeMCU Board https://amzn.to/2SZWLJ6
• NXP PN532 Breakout https://amzn.to/2VXHtGX
• itead NXP PN532 Breakout https://amzn.to/2sx4H9b
• Asiawill NXP PN532 Breakout https://amzn.to/2DqefsP

• Thinking of adding some feedback mechanism such as haptic, neopixel or led options.
• Need to publish the glue between this code and sonos.
• come up with some example automations for Home Asssistant for fun.
• photo/video of the final build (wood enclosure with wood sound blocks).

homie/legacy-songblock/rfid/uid 04905042763f80
homie/legacy-songblock/rfid/present true
homie/legacy-songblock/rfid/uid (null)
homie/legacy-songblock/rfid/present false
homie/legacy-songblock/rfid/previous_uid 04905042763f80

Assign a song to each tag/card/whatever. https://github.com/jayaras/sonos-agent

Binary sensor from a card being present or not.

binary_sensor:
  - platform: mqtt
    state_topic: "homie/rfid-reader/rfid/present"
    payload_on: "true"
    payload_off: "true"
    availability_topic: "homie/rfid-reader/$online"

Unlock your door with a specific uid from a card. (This begs for a proper MQTT RFID Device so you could look up based on a user).

alias: "rfid unlcok front door"
trigger:
  - platform: mqtt
    topic: "homie/rfid-reader/rfid/uid"
    payload: "04905042763f80"
action:
  service: lock.unlock
  data:
    entity_id: lock.front_door_2