… and I would like to go as far as to say, better drop the whole Bluetooth hype if you run Bluetooth on a raspberry, it will not work.
Note: HassOS on pi.
+1 on that.
I have the very same experience.
Any BT adapter turns up, but it is not possible to get BT devices visible in any form.
My man, you’re trying to get an unsupported device to work. Do you expect your car bluetooth to connect to a BT speaker? Or is it designed to only connect to phones? Same principle here. If it doesn’t have the functionality to connect to your bluetooth device, then it wont.
It took me a while, but with help of the forum, and people here, I was very able to get Bluetooth running on a raspi 4.
But as said by others here there is a limit in the support of devices, many do not work, stronger even, my Bluetooth tracker now sees a zillion devices around the house, but there is no way to interact with them like speakers and such,
I added a new Bluetooth dongle & it immediately was picked up by HA. Once configured it I grabbed my meat prob (Chugod) > this seems to interface with the Inkbird integration.
SOOOO Excited…
Smoked meat & smart home technology…what a time to be alive!
What no one has mentioned or replied is that we (as at least me) using HassOS image and that means RPI4 config file is to be updated by HA.
I’m getting error
Retrying setup: hci0 (49:02:91:02:89:88): Failed to start Bluetooth: [org.bluez.Error.InProgress]
Now if its config.txt file issue then what and how to fix it, its still HA WTH issue as its not a standalone installation. No one has been explaining how to fix this ?
Resolved the issue by updating the config.txt file in RPi 4 by doing this
#enable_uart=1
dtoverlay=miniuart-bt
No errors 
I appear to be missing something big because I have HA installed just a few days ago by imaging a card with the image from this link: https://github.com/home-assistant/operating-system/releases/download/9.4/haos_rpi4-64-9.4.img.xz and not only can I not find a file called “config.txt” anywhere but I appear to have no /boot judging from hunting around the filesystem with the Terminal add-on. I understand this is a Docker container so who knows what restrictions it has on what it can see, but I can’t find that file anywhere else in the UI either.
Consequently, I can’t figure out how to start troubleshooting my BT/Z-Wave conflict problem (which I guess is what I’m having). When I correctly configured my Z-Wave dongle, the Pi 4’s built-in Bluetooth stopped working. I gather the problem is that the Z-Wave device appropriated /dev/ttyAMA0 for itself, but then the Bluetooth device was not given another device path. I have the same recurring/reloading error message in my Devices list complaining about hci0 as the above users. There is no /dev/hci0 in my system.
Your diagnosis is correct, and to access the root you need to access it using Putty with Private Key to fix this in config.txt file.
Should be able to find some you tube video of root access to Pi with Private Key
Noob here, so I’d appreciate any help!
Been trying to connect a miflora device to rpi4 bluetooth, but hci0 doesn’t recognise everything, even at a dead close distance from the device.
I’ve included the le tracker script mentioned above, but still nothing…
So I quit and go for an external bluetooth adapter or am I missing something?
Thank you so much in advance!
Have you installed the Xiaomi BLE integration?
I have three of them with no problems, but I have to have a BLE proxy (ESP32) in each room I use them, otherwise the distance is very limited.
That was the key element missing!
Thank you so much!