More people are welcome to come and experience this new little plugin for quickly expanding HA's Bluetooth capabilities.
Find a USB adapter, plug it in, and the HA will start capturing the Bluetooth signals around it, which is how all Bluetooth proxies work, and of course DIYing them is inexpensive enough that any ESP32 development board can do it.
But there seem to be fewer of these direct USB-A sockets, which I think might help to make it easier for some people.
For ourselves, we use it to get the Bluetooth thermo-hygrometer signal in the room, which is pretty nice.
With the PLA material we initially used, in very high temperature areas (over 40 degrees), the shells may be slightly deformed (not affecting use) due to the addition of the heat buildup inside the esp32, we are experimenting with printing the shells in PTEG, they become less rounded in texture, though more stable in high temperature environments. This is something we are still testing, as a general rule it's hard to have such high external temperatures. We've designed as many heat sinks as possible into the housing to accommodate the heat dissipation needs of the ESP32.
HA's Bluetooth proxies may be unfamiliar to some, they are devices that use the ESP32 to quickly switch in and out every second through its dual-band switching ability, scanning for BLE ads, then stopping, sending them to HA, and repeating this all the time afterward.
They support multiple ones together, extending HA's ability to recognize Bluetooth.
Probably the most common use is to track the Bluetooth distance of a device such as a cell phone, which is used to determine the presence of the device. As for the rest is accessing Bluetooth devices, there are some devices whose Bluetooth signals can be interpreted, such as Xiaomi devices. Some other special devices require a connection mode where each agent can connect to about 3 devices, for example the LD2410C millimeter wave module can be connected directly using Bluetooth in this mode (but the real time rate is too high and is not recommended).
For ourselves, we especially like to use it to integrate BTHome devices, that's a very promising protocol, they are simple, just BLE broadcasts, capable of long range.