[APP][Pro] Östberg Heru

I can’t see any way to use the Medium speed through the modbus interface either, so I don’t think I’ll be able to solve this for you through Homey :neutral_face:. There is a user fan speed option control register, but that’s only for AC and not the EC fans.

Hey @kjeet90 ,
From looking at the control registers and messing around with the remote a bit further, I think I know what’s going on here. I think the 0x registers are to toggle certain modes on the device. Basically turning the device on or of, enabling/disabling away mode, enabling/disabling boost mode, and enabling/disabling overpressure mode. These are features that also exist on the gen3 remote from toggle buttons.
I think, the actual fan speed can be controlled by the 4x00001 register. with that register, you can set the fan speed from 0 = off, 1= min, 2 = standard, 3 = medium and 4 = max. Even though the documentation implies that it’s only for the AC fans, I think it also to control the EC fans.
There is also the 4x00026 register which allows you to set the fan speed for the boost mode.
All of these options are actually also available from the gen3 remote. This does makes sense because the remote is using the same registers to communicate to the unit as well so in theory, everything the remote is able to to you should be able to do with modbus as well.
Maybe I could clone the repo and help you out a bit? It would be cool if the app could have one extra tab with a couple of toggle buttons for on/off mode, boost mode, away mode and overpressure mode. And redesign fan speed the select tab to actual control the fan speed. And also add the accompanying flow cards of course.

The above proposal would also make the app a lot simpler. I see you made a method to send multiple coils at once in order to toggle certain modes on or off depending on which ‘fan speed’ you select. That would no longer be needed anymore as each toggle or select would only send one command.

I don’t have much time to work on the apps right now, so if you are able to do the changes and do a local install on your Homey to see if this solves it for you, that would be great. :slightly_smiling_face: Then it could be added to the public app later if it works as expected :+1:

Hi, my modbus device have A B + - Shall I connect the 0 to - ? Or shall I just not connect 0 at all? The power to the modbus device is on the +/- pins… so the - will have 2 connections, power and modbus…

I have A,B, GND (-) and VCC (+) on my device. I have A,B and GND connected, so try to connect the - if you haven’t and it’s not working already.

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Okidoki, I will give it a try, hope it will not break… then this modbus to wifi device can be on the ok hardware list :wink:

That works like a charm :smiley:
I have the wifi to Modbus device Elfin-EW11A to a Östberg HERU 100 S EC and all the data looks perfect!
Connections is “A”->“A” “B”->“B” and “0”->“-” the power for the Elfin-EW11A is using the “-” and “+” so the “-” is used 2 times.
Time to try out some flows :slight_smile:

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