Bluetooth is pretty much universal on mobile phones, and as a result there are a few misconceptions about what can be expected in Home Assistant. Here are some of the things you need to know.
Not all Bluetooth adapters work with Home Assistant
There is a list of known working adapters in the Bluetooth docs.
Even if you have an adapter and the Bluetooth integration, HA isn’t going to connect to anything
Think of the Bluetooth integration like a hardware driver in Windows - it connects the adapter with the rest of the machine. If you want to do anything, you have to add another integration - for tracking, for example, Bluetooth Tracker and Bluetooth LE Tracker provide basic functionality.
There is no generic “pairing” function in HA like the one on your phone
For sensors, you need an integration for each manufacturer whose devices you want to connect. There’s a list of integrations here. An add-on like the Theengs Gateway may allow you to connect to a wider range of devices.
This topic is part of the community-driven cookbook where you can find other topics you might be interested in or might like to contribute to.
No, HA does not pair with Bluetooth speakers
If you want to write an integration, go for it!
You may have read that you can only connect to three devices
This is normal for a Bluetooth adapter, nothing to do with HA. Some of the high-performance adapters listed in the docs will connect to five devices and a few will connect to seven.
These are active connections, where data is being exchanged. You can use Bluetooth and Bluetooth LE to track as many devices as you like. (Add the Bluetooth Tracker and/or the Bluetooth LE Tracker integrations).
Most trackers only detect Home and Away
If you want to do room-level tracking, you need another integration such as Bermuda.
You can only track phones easily if they have the HA app installed
Android and Apple phones change their Bluetooth MAC addresses every few minutes as a security feature. The HA app provides its own iBeacon, otherwise to track a phone you need to find its Identity Resolving Key and set it up in the Private BLE Device integration.
You can find out how to get a phone’s IRK here.
If you have range problems, you might consider adding some Bluetooth proxies
These detect nearby Bluetooth signals and forward them to HA by wi-fi. They are very cheap, but you have to flash your own device.