MR24HPC1 Communication Issue with ESPHome

ESPHome
21

When did yours stop working? Was it over Christmas or earlier? And can you pin point it to a specific release?

I do think its partly down to the board as the fact I got one of them working again, but the fact it isnt repeatable means there is something odd with how the ESP8266 board is operating or dealing with UART.

It is just oddly suspicious that it impacted your 3 boards and my 2 boards at the same time…

22

And several other people posted the very same issue and no response/support.
I may be wrong but it was around I think November 2025.
I just ignored and we used the wall switch as I had no time for this.

I have one in the WC, another in the Kitchen and the third has not been ever connected until I got the issue with the other 2.
So still I can not believe is a hardware issue.

In my case I use the Seeedstudio Kit so all of them use:

XIAO ESP32C3
MR24HPC1

I also had the most incredible thing that was after several tried one worked but just for 1 boot. I figured is fixed, moved it to the kitchen and…
Not working anymore.

So…

23

Did you ever replace them with anything or just left them not working for the time being?

The light in the bathroom is fine as I can control it with the switch but the kitchen cabinet lights don’t have one as they were controlled with a relay also connected to the same board I pulled out, so they are currently unusable until I find a fix.

I wonder if there is an update to the mmWave sensor such as a firmware update or something.

EDIT: Just looked on the Seeed website and what is listed is over 3 years old so my guess it hasnt had any updates in the interim. I am tempted to cut my losses with these sensors and try something new when they turn up, dont really want to spend the next few days repeating the same steps over and over and getting different results.

24

So far did not replace because just now had time to come to foruns and raise the issue. Can not be devices/sensors issues, must be something in ESPHome, a breaking change.
These sensors work flawless and never had any issue until now as you and many others.

Going to open a ticket in Seedstudio to try to get to the root cause.

If you really want to move on, use a LD2450 - simple, cheap and reliable.

25

Said I wasnt going to, but to satisfy my curiosity I did another couple of tests. I moved the currently working mmWave board and connected it to the ESP8266 in the downstairs bathroom. No response back from the controller. Same issue as I had at the very beginning of this thread.

Ok, let’s move the sensor back to the test board that was working, and also nothing. Also tried the new sensor on the old board and still nothing. Below are the lists of tests I have tried, noting despite everything in test 7 & 10 being the same I got the different results.

  1. Old Sensor 1 - Old Board 1 - Old Config - Didn’t work
  2. Old Sensor 2 - Old Board 2 - Old Config - Didn’t work
  3. Old Sensor 1 - Test Board - Old Config - Didn’t work
  4. New Sensor - New Board - Old Config - Didn’t work
  5. New Sensor - New Board - New Config - Didn’t work
  6. Old Sensor 1 - Old Board - New Config - Didn’t work
  7. Old Sensor 1 - New Board - New Config - Works
  8. Old Sensor 1 - Old Board 1 - New Config - Didn’t work
  9. Old Sensor 1 - Old Board 2 - New Config - Didn’t work
  10. Old Sensor 1 - New Board - New Config - Didn’t work
  11. New Sensor - Old Board 2 - New Config - Didn’t work

So on that I am just going to give up with this. I am going to drive myself mad repeating the same thing over and over again expecting a different result and put this down to a combination of dodgy sensors that haven’t been updated in a number of years with ESPHome changes. I dont have anything else to support the latter. Annoying that I do have 5 of these…

1 Like
26

The sensors are not updated but they were working PERFECT until some update ruin them.
Would be really great if ESPHome devs could support people on this.

Tomorrow morning I will try a deep dive.

27

You really should focus on this. Devices are or are not updated? It can’t be somewhere in the middle…

28

Hey there

I was referring to the comment "EDIT: Just looked on the Seeed website and what is listed is over 3 years old so my guess it hasnt had any updates in the interim. I am tempted to cut my losses "

Agreed the latest firmware is “old” from Seeedstudio and even the kits I own are discontinued. But this does not mean anything to our discussion. Could be “old” but was working perfect until I believe November.
I lack the tech skills to properly troubleshoot the issue but I am willing to do so If some support is available.

The facts are:

  • something broke it and several people report the same since the same date
  • all have the same issue - the sensor stopped sending data
  • the esp+sensor were not touched or yaml changed - at least i can speak for me
  • wife is upset :smile:
29

My point you quoted is that there doesn’t seem to be any updated firmware from Seeed for these devices. I use another mmWave on my Everything Presence Lite and that needed a firmware update to improve reliability.

I’m not saying it is the reason it doesn’t work, but it could be a factor if there is a hardware issue that could’ve sorted with a firmware fix.

It might also be caused by some change with ESPHome but there doesn’t seem to be a fix for that easier.

I have just lost my patience with them. They have worked flawlessly but none currently do. If you have any success debugging let me know and I can see if I can replicate, else I might just try resort to the new sensors I bought when they arrive.

30

The mystery continues.

I would adjust the title of this thread to include MR24HPC1 and exclude UART (Since I think that is now ruled out?).

If it is software issues then we should get a few more find this thread and confirm the symptoms.

I would say if you get one more person who has similar symptoms then raise an ESPHome issue.

There is only one open issue for that component.

Apparently you can test your sensor independantly of your ESP. I would try that if you still have any debug juice left:)

limengdu on that thread seems to be the code owner.

31

Hey there

So after spent some time looking into this seems that the ESPHome version after 2025/10 has implemented changes to the class members and variables definitions from previous versions, I would say probably to get more free space on the device memory and standardization… maybe.

So, based on my install and config I find that:

  • seeed_mr24hpc1.cpp expects many member variables like:
    custom_mode_number
    scene_mode_select
    product_model_text_sensor
    movement_signs_sensor
    and more…

Those members are declared in the header only if certain config options exist in ESPHome ≥ 2025.11, the component seems to have been partially refactored so resulting in CPP file references members that are no longer declared.

One solution could be to setup a specific external component but this would probably be broken again in further updates of ESPHome.

Possible solution:
Ask Seeedstudio to update the files for the sensor to align with recent ESPHome versions and align with ESPHome devs to keep it supported.

Ask ESPHome devs to maintain support for these devices.

32

Issue opened:

1 Like
33

Just an idea: Have you tried esp-idf for the framework?

I do note the relevant code was updated on GitHub two months ago. For process of elimination, roll back to an earlier release such as September and verify the problem is actually software and not hardware. I strongly recommend you clear your ESPHome cache before attempting a compile with an older version of ESPHome so you do not get a corruption of old and new files.

34

Perhaps it relates to this?
I haven’t followed the crumbs.

35

You already quoted those earlier. First closed without attention, or just too busy?

36

Those newer ones should link to specific messages.
Might not be relevant just had a peruse of a few threads and thought I’d post them here.

But yes, a bit superfluous I guess.

37

I do not have a backup from 10/2025 and fear to create more issues with the many other devices I have. For now I will see what the issue turns into and then, if needed, will patch it myself but not much time for it.

I am 100% sure is a breaking change in ESPHome 11/2025.

38

I have updated the title. Might get get a bit more specific interest now.

1 Like
39

Hello all!

Just updated ESPHome version and the Seeestudio devices and all is working fine!
ESPHome guys ROCK!

40

Can you provided your formatted config below? I have made no changes updated to the latest ESPHome and same result, aka no response.