Heya, long-time HA user here, but first time poster here.
I've been using Xiaomi MIJA thermometers LYWSD03MMC for quite a while, with BLE-based integration in HA.
I've bought some more recently, with firmware 2.1.1_0159, and I cannot integrate them in HA anymore.
Here's what I tried thus far:
Telink flasher Telink Flasher with the old "Do activation" route → doesn't work with this firmware, as documented
HACS integration Xiaomi Home → I can add the thermometers in HA, but both temperature and humidity readings remain "Unknown". According to the FAQ this might be "normal", because I haven't linked the sensors to Xiaomi Cloud (I don't want to) and they're not reacheable in LAN mode
HACS integration Xiaomi Miot → I can add the thermometers in HA, but both temperature and humitidy readings remain "Unavailable"
There are a few more options I have not tried yet:
Flashing the custom firmware by the Telink Flasher maintainer
Telink Flasher via the "Do Login" path
As this is getting a bit tiresome, I was hoping someone could point me to the currently (supposedly) working integration, to prioritize it before other tries.
Hopefully, this thread will also help others in the future jumping directly to the currently working solution.
Xiaomi has apparently been using cheaper/worse (and different) chips in these, and they cannot be used with Telink anymore. You basically need old hardware.
Have you seen this warning btw? Requires registration in MiHome.
First of all, thanks for your answer!
I'm not sure I understand what exactly you're answering to, though.
Are you saying that there is currently no way at all to integrate these thermometers in HA? I'd find that very difficult to believe.
Or were you explaining why some of the ways of integrating them in HA I've mentioned no longer work? If so, can you calrify which ones don't work and which still do?
About the requirement to register the devices in MiHome, I don't mind that --- in fact, to try the 2nd and 3rd options in my list (HACS integrations Xiaomi Home and Xiami Miot, respectively) I had to do so already. What I don't want to do is to regularly route my IoT readings to the Xiami Cloud service. But if it's a one off, e.g., to retrieve the appropriate keys, that's fine with me.
I'm using some of these thermometers in HA following the instructions cited in the post of @Vitruvius. As stated you have to register the devices with Xiaomi MiHome first, as you need to extract the keys before you can flash the firmware that integrates with HA via BTHome.
So apparently Xiaomi Mijia has been using different hardware revisions over the years. When I bought mine around the end of 2025, there were maybe a dozen different "flavors"... all under LYWSD03MMC.
I was lucky that mine was still supportable... with the latest flash-able method and firmware that was only available literally (at the time) only 1-week before when my LYWSD03MMC arrived.
And the earliest mention of the same hardware revision has been out there for a good 6 months.
(Meaning, if I buy mine during those 6 months, there would not be any feasible route for me...)
(I have since flashed the zigbee version of the firmware, to replace the BLE firmware.)
So, what I'm trying to say is that, if nothing works, you might have to wait.
Thanks, this is getting a little clearer for me, but not quite enough
In particular, the post mentioned above (a GitHub issue) say " 1. Using alternative software, get all the keys for this thermometer.". What's this "alternative software" and where is it?
Answering to self, after a successful attempt (with multiple thermometers).
What works today (as of July 2026) to integrate LYWSD03MMC Xiami Mijia thermometers, with firmware 2.1.1_0159 is:
Register your thermometers with Xiaomi Home (I did this using the Android app). (Just register them, so that they show up in the app when you open it; there is no need to setup automated/regular data transfer from your sensors to the "cloud".)
Use the Xiaomi cloud tokens extractor to extract encryption keys. I've run it as a standalone Python script (there is no need to run it within HA, as suggested by the main installation methods. The tool will ask you your Xiaomi username and password, and take care of 2FA (asking you to provide the received codes, e.g., via email). When asked for the relevant country/server, it is possible yours will not show up, but you can try all servers leaving the choice empty (FWIW, in my case the "right" answer was "de", even if my Xiaomi-declared country is a different European country). Contrary to what I've seen documented elsewhere, there is no need to declare "China/cn" as your country in Xiaomi Home, which will make the process more painful if you can't read Chinese.
When done, the script will print out one block like the one below for each registered device (data below are fake, but the syntax is correct):
You can now add the devices in HA, using the built-in "Xiaomi BLE" integration. There is no need to add any additional integration like "Xiaomi Home" or "Xiaomi MioT". Also, there is no need to do any activation using the Telink flasher website anymore; nor to flash the thermometers (unless you want to, of course). When asked for how to authenticate the devices, chose "Enter encryption key manually" (the "Xiaomi login" option will not work, as 2FA handling is not implemented in Home Assistant right now) and provide the value of "BLE KEY" from the relevant record above.
