I’ve seen people asking about support for Flexit ventilation systems, with some fairly complicated modbus solutions as options, but I haven’t seen any attempt at creating a Flexit Homey app. I’ve read that Flexit’s own system, Flexit Go, is a closed app and api and they’re not sharing any information. But I’ve also seen that there is a Home Assistant integration that only uses the BACnet protocol over ethernet, no modbus connection necessary: Flexit Nordic (BACnet) - Home Assistant
Has there been an attempt to create a similar solution for Homey, or can anyone spot any reason why that’s not possible? It looks possible to me, but I’m not that deep into the limitations of Homey app development. I don’t have a Flexit ventilation system now, but we are building a new house and that brand appears to be the default option, so I’m very curious to know if it’s even possible.
Yeah but that’s exactly what I was referring to in the part of the sentence that wasn’t included in your quote. What I haven’t found is an attempt to create a Flexit Homey app that does not rely on modbus and cumbersome CLI installation, but a “normal” app with a backend based either on Flexit Go or BACnet.
Oh , I’m so sorry, I think in solutions
The only thing missing is “the app store”, but that’s just a GUI to CLI.
At least there IS a Homey app, and CLI install might be easier than you expect.
Plus there’s enough forum users who can help you out, just ask when you get stuck.
Thanks, but you are assuming that what I’m really asking for is help to get it working. I’m not.
I don’t expect CLI installation to be difficult, and I don’t expect the rest of the process to be so difficult that I would need assistance. I just don’t like the solution. First you need to buy the modbus gateway, then you need to buy a special wire harness, then you need to physically open the ventilation device and connect everything internally, then you need to set up the modbus gateway correctly, and then finally install a Homey app through the CLI. All of that is interesting in its own way, and great if you have an older model that can’t be controlled in other ways, but not so much if your model can be controlled directly through its ethernet connection.
That’s why I’m asking if anyone knows of an attempt to get Flexit support through the ethernet connection alone. For instance if someone has reverse engineered the Flexit Go api by decompiling android apps, or – more likely – if someone has tried the BACnet approach of the HA integration. Maybe someone is working on it right now, or maybe someone has tried and failed for some reason, or maybe someone who is deeper into the limitations of Homey app development can see a reason why the HA integration could not be ported to Homey.
All of that is interesting to me. And if no one has tried, and no one can see a reason why the HA approach can’t work on Homey, and I end up with a Flexit ventilation system myself, I might even give it a try if no one else does it first. But, on the other hand, if the consensus is that it can’t be done, or it’s super difficult, I may ask to get a ventilation system from a different vendor installed instead.
It depends on how the app authenticates. Some smart home apps sign or encrypt requests before they leave the phone. This way, an interception tool like HTTP Toolkit can only view encrypted data. In this case, it’s unlikely that you’ll be able to reverse engineer it
However, if the app uses standard HTTP(S) communication, then it’s possible to intercept the requests and perform the same requests from a Homey app.
Yeah, it definitely isn’t guaranteed to work, but sometimes you can sort of piece things together. I’ve been using a combination of Android app decompilation and HTTP Toolkit to reverse engineer some waste management data fetches for various providers in another Homey app I made. Some were not successfully reverse engineered, but others were. And I’m not particularly good at it.
That said, I think using a direct BACnet connection like the HA integration does would be more likely to be successful.
I also used HTTP Toolkit with Android emulator (Frida interception method) for multiple apps, such as Duux Gen2 and HomeWizard Link. But the larger apps like Tuya all use encryption.
Do you also have the device? If you don’t, you can also install the app on your emulator and then create an account. Sometimes, you can see the requests and check if they’re encrypted. You can’t see all requests, but you can see those where the app requests a device list from the server
Thanks. I don’t have the device, no. As mentioned above, the device appears to be somewhat of a default option when building our new house, and I may end up with one in the future. Just to be clear, even though I appreciate the tip, I’m not asking for help to reverse engineer the api. I am asking if anyone knows whether the lack of a non-modbus based Flexit app for Homey is because no one has properly tried to make one, or because someone has tried but failed.
Would love to see a app for Flexit that don’t require Modbus/CLI.
I have a Flexit Nordic S4 which I currently control using the Android version of the Flexit GO app. Let me know if I can be of any help with testing etc. if someone decides to have a go at making an app.
Out of curiousity, what is it that you would like to do with a Homey app for Flexit?
What I did creates to devices per unit, one thermostat that deals with things related to the heater coil and a fan device that deals with home/away-mode, humidity sensor, filter lifetime alerts etc. I did not really want to mess with fan speeds and such from Homey as extract/supply fans need to be set correctly in relation to each other to maintain pressure bias.
Not entirely sure if letting each unit be one or two devices is a good thing or not, but it made sense for my use cases at least.
Very interested in hearing your use cases and see if it is worthwhile trying to publish this app.
I would probably trigger different ventilation modes automatically. Like Away when I’m away for some time, and Home when I’m back, and early triggering of High based on bathroom humidity changes. I’d probably also want to trigger the Cooker Hood mode early, instead of waiting for the under-pressure detector, but it looks like that can’t be done through software (not the Flexit Go app at least, if I’m reading this correctly). I’d be interested to know if it can be enabled through the BACnet interface.
I’m not sure if I would change the setpoint temperature, but I could imagine setting something up to prevent the ventilation and the heat pump and the heated floors from fighting each other.
So I’m not sure if I would control it through the actual devices much, it would probably mostly be based on flows.
I don’t think cooker mode is available, as that one seems to be specifically triggered from signal cable. But the fireplace mode is sort of the same principle–significantly boosting supply air and limiting exhaust air and that one can be triggered from BACnet. The BACnet commands temporarily set those modes though similar to how the app and buttons work.
Flows is the main thing for me as well, but interesting to know what kind of flows people want to set up. Changing modes, turning on/off the heater coil etc is definitely doable, responding to the humidity sensor etc is definitely doable.
Great work. I already had the modbus version installed. Tried this one and it works fine. The only thing is that there is no data on the Extract Air Temperature
