Bluetooth (BLE) for sensors and presence
- Home Assistant's Bluetooth integration supports Bluetooth Low Energy devices. Bluetooth Classic devices are not supported.
- Many sensors simply broadcast readings (advertisements), and the Bluetooth integration collects them. Others need a connection (locks, some thermostats, some sensors), which uses one of a limited number of connection slots.
- A built-in USB adapter on your server works, but the docs point out that Linux kernel updates have broken Bluetooth in the past and that driver support lags. Their suggestion is often to use ESPHome Bluetooth proxies (ESP32 boards around the house) instead, which especially helps if Home Assistant runs in a virtual machine. HAOS includes Bluetooth patches if you do use a local adapter.
- Proxy hardware placement matters. The ESPHome docs say to keep proxies at least about 3 metres from routers, switches and other network equipment because of electromagnetic interference, and close to the Bluetooth devices you want to reach.
- Active scanning increases battery drain on battery-powered BLE devices, so only use it when something needs it.
- Phone tags: NFC stickers and cards work out of the box with the Home Assistant mobile apps. The Tags docs note that on iPhones only the XS, XR and iPhone 11 or later support background NFC tag reading. Tags show up as entities and have a trigger you can use in automations.
- Standalone readers: anything that can read an ID can send a "tag scanned" event, for example an ESPHome board with a PN532 reader (see the project thread). The HA docs show an "RFID jukebox" where each tag starts an album or playlist, which is a great kids' project.
- Smart door locks and readers with their own app: many consumer products pair over Bluetooth with a phone app. Check whether they have an official Home Assistant, Matter or local API route before buying, because some can only be controlled through the vendor cloud.
- An RFID/NFC tag ID (UID) is just an identifier. On many tag types, anyone with the right reader or phone can read it, and some cheap tags and cards can be cloned. Treat UID-only tags as a convenience (music, scenes, turn the lights on), not as proof of who is there.
- Do not use a lone tag scan to unlock a door, disarm an alarm or open a garage. If you must, combine it with a second factor, keep the reader inside the secured area, and use readers designed for access control. The PN532 module from this project is a hobby part, not an access-control product.
- Bluetooth presence ("my phone is nearby") can be spoofed or fail. Do not rely on it as the only way to unlock something.
- Keep Bluetooth devices updated, and remove old devices from Home Assistant when you retire them.
- Add the Bluetooth integration in Home Assistant and see what is discovered under Settings > Devices & services.
- Build or buy an ESP32 Bluetooth proxy for rooms where range is poor.
- Try a few NFC stickers with your phone to get the idea.
- Only then add a dedicated reader with ESPHome if you want a wall-mounted scan point.
Question for the group: what are you using Bluetooth or NFC/RFID for around the house (presence, locks, kids' music tags, door readers)? Anything that proved less reliable than you hoped?