HomeKey Reader Relay

PN532 -> ESP32-C3 (this part) -> Home Assistant

In development. NOT FOR USE!

Home Assistant UI setup

HACS

1. Settings -> Devices & services -> Add Integration.
2. Search for HomeKey Reader.
3. Pick the advertising ESP32-C3 reader.

Because the manifest also contains a Bluetooth matcher, Home Assistant can offer the reader automatically when it sees the service-data advertisement.

Install toolchain

brew install libgcrypt glib pixman sdl2 libslirp dfu-util cmake python

brew tap espressif/eim
brew install eim

eim install

source "$HOME/.espressif/tools/activate_idf_v6.x.x.sh"

Flash the firmware

cd esp32
idf.py set-target esp32c3
idf.py -p /dev/cu.usbmodem101 flash monitor

Mock Flow

ESP32-C3
  mock PN532 UID (DE:AD:BE:EF)
       |
       v
BLE service-data advertisement
       |
       v
Home Assistant Bluetooth
       |
       +--> HomeKey Reader config entry
       +--> sensor: Last NFC UID
       +--> event: homekey_reader_packet

Service UUID:

7b1e0001-7b1e-4a11-9abc-0123456789ab

Advertisement payload after the UUID:

byte 0      protocol version = 1
byte 1      message type = 1 (mock PN532 tag)
byte 2..3   sequence, uint16 little-endian
byte 4..7   mock UID = DE AD BE EF