How to start hacking an IOT device that has no HA integration yet

It is hard to know what is meant by this

The robust system design means that users will retain full control of the heating even if their Internet access in interrupted.
Users can always access all programming options and functions via the built-in display…

This could mean either

  1. The app doesn’t require the internet, or more likely

  2. If the app doesn’t work because the internet is down, then you can always use the display to control things.

Anyway decoding the app–server communication will give you control, even if it is via their server, undesirable as that is.

@ianadd how did you go with this?

I have the same thermostat, and elec floor heating from coldbusters, and it’s been installed for nearly 9 months now. However only just now is my house switchboard getting upgraded to connect it.

Did you make any headway with it?

No, ive ordered a couple of bht-002 from ali express. The first is installed and works via Smartlife rather that their intended app. I use tuya integration to control but not happy as it only delivers room thermal sensor data not floor. The second one is somewhere in a covid cloud atm. When it arrives i plan to hack it to tasmota and use mqtt.

I initially looked at other thermostats that were already integrated with HA, however I have reservations of using cheap units that could potentially cause a fire.

Hopefully today I get power connect to the bathroom (if the sparky shows up) and I can finally power this thing up and start working it out.

Let me know how you go with those BHT-002 units.

Ta

Hi Ian;
Powered up the OJ Electronics thermostat today - it’s a POS. Can’t actually turn the system off, and refuses to pair with the app - as if there is no “user account” but no where to set one up.
How far down the road have you got with your BHT-002?

ta

there’s other threads about this product here. to cut to the end the best solution is local control.
you can flash it with tuya convert and the working bin is here

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@matticas, still waiting for one from China/Singapore …

The one I received back in March is installed in covid riddled UK and works with Smartlife and HA using tuya cloud but not as I would want. I can’t tasmota it as I am the other side of the world. Got to wait for the next one, maybe another few weeks I fear.

Thanks Juan; this is a good read.
I ended up ordering a BHT002 - given the one key feature missing from the unit I have: no soft off button. So if you want to turn it off to the next schedule, there is no way to do this without re-writing the schedule etc. pretty crappy I reckon

@ianadd, there is another post in this community with a solution for the OJ WiFi devices, but it’s still going through the cloud. So what @paulcam mentioned remains.
Link to other post:

Anyone had more luck integrating the MWD5?

Also putting in underfloor heating soon, and most of the local (Australia) suppliers seem to sell some branded version of the MWD5 as a standard offering.

For support reasons it makes sense to go with it, but some Home Assistant integration would be nice!

Has anyone managed to integrate the MWD5? I guess for the most part the thermostat just does it’s thing, but I am conditioned to try and integrate anything new that gets installed now!

I just installed underfloor heating in a bathroom and decided to go with the HWSMWiFi thermostat. I integrated it using the new Tuya integration, and it appears to be mostly working: I can see the temperature reading from the underfloor sensor, and I can change the target temperature, but I cannot change the mode (smart/anti-frozen/manual).

Before installing the thermostat I opened it up and can confirm it has a TYWE3S chip (ESP8266) built in. However, I did not try to flash it with the likes of ESPHome or Tasmota due to a lack of information to give me confidence that I would work out.

Somebody at OpenHab made an integration for the OJ Electronics MWD5. It appears to be incomplete/abandoned but it shows it’s possible and the code may be a useful reference.

Sadly it’s cloud based rather than local, and it seems you need to obtain your distributors API Key in order to access the API.

Also, it seems nuheat also rebrands the OJ Electronics devices, and publishes a very detailed reference guide. It may be useful:
https://api.mynuheat.com/

If I end up with one of these, I may have a go at creating an integration for HA.

still no luck on a integration on this?
Best wishes

Hi

A couple of months ago I made a mqtt gateway for my Micromatic thermostats. I simply replicated the http calls to their API, and publish stuff to the Mqtt broker on my HASS.

Its not maintained and I dont remember the details. Sorry for not documenting, but it was not supposed to be a public repository to begin with. Anyway, if it helps getting any closer a liable solution, please steal and copy whatever you want from my code.

I dont have the mwd5 1999 thermostat tho. This gateway is made for the older Micromatic MSW5 ethernet gateway and the MSW4 thermostats. However, since the gateway basically make http request to the micromatic api, I suspect it would work with other thermastats as well (with minor changes probably).

And last, the repository should be possible to install as a custom add-on in home assistant directly. If there is any interest I can update the readme on github with instructions. However! The code is not stable at all, I have scheduled a daily restart of the add-on due to API/websocket timeout which occurs every 2-3 days. I dont have the time to fix anything, so Im sorry, but you’re on your own.

https://github.com/siglun88/hass_micromatic_gateway

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I made an integration for this some time ago and just placed it on a public repo. The code needs cleaning but it works. More info can be found in this thread:

it’s my understanding that the mythermostat.info APIs are fully compatible with the nuheat package being used by home assistant today. If anyone would like to try it out, you can check out this package, add the appropriate URL to nuheat/config.py and test locally.

if it works, feel free to submit a PR to the python package and then we can get HA updated to support these thermostats.

Hi exxamalte.

Just wondering how this integration with the HWSMWiFi thermostat is working.

I need to make a purchasing decision fairly quickly on an underfloor heating system for a small bathroom and want a thermostat that I can incorporate into Home Assistant. It seems like there has been some progress with getting the MWD5 integrated.

I really want something with no cloud communication required. But it doesn’t seem like such a device exists.

Originally I used the official Tuya integration and that worked in principle. However, I quickly moved to the Localtuya integration which works pretty much the same way, i.e. I can see the actual and target temperature. With Localtuya the mode is always “Auto” and never changes and I can’t remotely change the mode of the thermostat.

Overall, a pretty underwhelming experience. Unfortunately I haven’t found any good alternatives for these type of underfloor heating systems.

Did this pull ever make it in. i see it still outstanding and trying to add in my warmtiles thermostat if possible.