EvoHome HGI80 + OpenTherm boiler module

[rogerrabbit]

Haha Dan, doznes of kudos to you. I will give it a shot altough i must say I have never compiled source code.
On my way!

[DanD]

If your Pi isn't already set-up for compiling, I suggest you have a search on the automatedhome forum and you should be able to track down a complete Pi image that a user has recently put together to make it easier for setting up Evohome with a HGI80 in Domoticz. This might be of use to you if you have a spare SD card lying around which you can transfer the image to. This image has all the necessary libraries already installed to allow re-compiling of Domoticz and you should just need to follow the 'cmake' and 'make' commands outlined in the Domoticz wiki for installing on a Pi once you've been able to clone the code from my repository.

Let me know if none of this makes any sense and you need more details.

Good luck!

Dan

[DanD]

Here's the link to the thread which has a Pi image containing all the necessary set-up for to get the HGI80 working in Domoticz and it has all the libraries ready loaded for re-compiling Domoticz source updates:

http://www.automatedhome.co.uk/vbulleti ... -installed

[shutty101]

Please can you clarify for me, can this solution be used to control some HR92 valves with just the HGI80 interface and NO evohome connect or
has anybody been able to send setpoints to the hr92 with an 868mhz transceiver directly. Does this code rely on evohome connect being in place.
I want to create a basic zone without needing the full evohome connect solution.

[DanD]

@shutty101

Hi,

The simple answer to your question is unfortunately no. The Domoticz Evohome code's functionality requires that the system has already been configured via an Evohome controller and it doesn't replace the controller. Instead, it provides additional control and logging capabilities whilst the controller continues to manage the overall time schedules for each device. The code could be extended to provide this kind of control and replace the controller, but it's not something that's in my plans to be developed.

Dan

[shutty101]

Thanks for the clarification, I suspected that was the goal and outcome of this development, but are you also confirming that from your experience with this environment, I could technically control some HR92's with just the HGI80, eg bind them and read status and write a setpoint temp etc. I have seem evidence on forums, where the HR92 have been read using just an 868mhz receiver, but I dont know if anyone had sent settings to the HR92's eg is any honeywell proprietary encryption or anything getting in the way or is something inherent in the way it works with the controller means you are stuck/limited... I need to simply isolate a few radiators in the morning for a few hours and the easy option may just be to go purchase a zwave trv for my current system. (choice is poor) I have some hr92's but no controller , I purchased, mistakenly believing that they were supported as a device by smartthings. but the integration is cloud to cloud, which means if i want the nice zone features of the evohome, i sell my nest etc and make that purchase instead. As a programmer of old, I quite like the idea of just coding something directly, but don't have the time to start from scratch. The HR92 seem very capable, hence looking for an affordable approach. I appreciate any further insights you could provide.

[DanD]

Hi,

Yes, happy to confirm that you can definitely control a HR92 in this way and possibly some of the early (pre-Domoticz) examples did try this out (they may still be lying around in Github). All of the pieces of functionality you'd need exist in the Domoticz Evohome code (evohome.cpp), but it's not configured to work in this way. Here are a few pointers to some hacks that you could make to evohome.cpp to possibly get this working, but realise that this will take some time to pull together:

The code looks for device type #1 to identify the controller and doesn't proceed until it finds one. If you hard-coded the controller to a dummy value it should at least get the code running. It will obviously fail to receive any of the necessary zone set-up info that it needs, but you may be able to activate the 'All sensors' function which adds any temperature sensor devices that it detects and your HR92s may show up if they are sending any messages in their unbound state. You'd then need to tweak the 'bind relay' function to bind the HR92 so that it responds to messages from your dummy controller.

Alternatively, if none of this works (I've never tested it out) you'd have to extract the following pieces of the code and get them running together with a dummy controller ID:

binding
keep-alive
zone_setpoint

Once the HR92 is sent a setpoint it will send out a heat_demand message on a regular basis which reflects the setting of the TRV and you'd need to come up with some algorithm of how to link this to your boiler control, the simplest would be demand >0=boiler on. I think the HR92 will do the rest and gradually reduce the heat_demand until the setpoint is exceeded by a certain amount. Do you already have a way of controlling your boiler that you can link in to all of this?

Hope this is of some help.

Dan

[rogerrabbit]

Well, controller functionality is definately worthwhile since the original evohome controller kinda sucks (imho) in doing a good job:
- restart of the burner system each 10 minutes (burning your pennies)
- the temperature oscillates with +- 0.5 C (delta 1 C)

So would you agree it may be beneficial to get rid of the 10min restart cycle -and- improved PID control of the temperature? I am pretty sure a lot of people would be very happy to see this
although quite a stretch to get it all in: you would need some PID model based on heat dissipation for each zone (I could help) and be able to send the right data to the opentherm burner system.

Cheers



Sent from my iPhone using Tapatalk

[DanD]

@rogerrabbit

OK you've convinced me . I'm willing to offer some support to this, at least by developing the Domoticz environment that permits a 'headless' (controller-free) Evohome device set-up. I have to admit that I'm a big fan of the Honeywell Evohome system and I've found that in my set-up it's reduced my boiler's gas usage by approximately 40%. This is with a modern Glow Worm condensing boiler which initially had all their fancy external controls with wireless climapro2 rf and outdoor temperature compensation, but I replaced these with Evohome.

I'm a bit sceptical on how large an improvement might be made over the Honeywell TPI versus overall comfort (e.g speed of reaching target temp and cool down), but it's an interesting experiment. I think I can help by setting up the overall Domoticz environment that will allow a controller program to be dropped in, but I don't think I'll have the time to get involved with alternate algorithm development and testing. I'll leave this bit to others, especially as I don't have an opentherm boiler and I'm just using the simple RT connection between my boiler and Evohome. My set-up would also require additional work on an Ebus interface and control programming for Glow Worm, which I don't think openhab currently supports. I'll send you a PM and post an update in a new thread when I've set-up a development branch, probably in a few weeks time.

Dan

[rogerrabbit]

Hi Dan, if possible would you be willing to provide some directions for the readers to follow along? After loading the img and ssh-ing into the setup one needs to load your branch.. how to proceed with git etc ?
I can confirm the HGI80 is functioning with this setup.
Here is what I did:

$ git clone https://github.com/Evsdd/domoticz.git
$ cd domoticz
$ cmake -DCMAKE_BUILD_TYPE=Release CMakeLists.txt
$ make -j 3


cheers,

[DanD]

@rogerrabbit

Edit: I'm not sure whether I mis-read your post or whether you made an edit, but I think I must have misunderstood what kind of info you were looking for (as you've already done exactly what I've written ). Could you give me a couple more pointers?


Original post:
If I've understood correctly, it sounds like you've got the Pi image file which contains the Domoticz + HGI80 drivers already set-up? What I suggest you do is create a git/dev-domoticz under your /home/pi directory (I'm not 100% sure of the directory that Domoticz is installed in this image as I haven't actually tried installing it). If Domoticz is already installed in this directory, just create another unique one. The follow these modified steps from the Domoticz Pi install wiki:

Assuming your starting in the directory where you want to install Domoticz, newbranch is the name of the branch from my github area that you want to install and you're installing Domoticz in the dev-domoticz directory.

Code: Select all

cd ..
git clone -b newbranch https://github.com/Evsdd/domoticz.git dev-domoticz
cd dev-domoticz
cmake -DCMAKE_BUILD_TYPE=Release CMakeLists.txt
make -j 3

That's it! The make -j 3 often fails on my Pi as I think it runs out of memory. If this happens just type 'make' with no options and it should pick up from where it crashed and compile successfully although a little slower than before. It'll be a few weeks until I've been able to put together the branch for the 'headless' version of Evohome. I'm pretty active in 2 other development branches at the moment: 'multi-controller' (this allows Domoticz to work in environments where there are multiple Evohome or other Honeywell wireless heating control installations), 'command_ext' (I'm trying to extend the list of commands understood by the code) and there should be a 'repeater' soon (this will allow the HGI80 to act as a repeater for installations where one or more devices has trouble with losing connectivity with the controller).

I'll let you know when I've created the 'headless' branch.

Hope this helps.

Dan

[rogerrabbit]

@Dand
Yes, I am trying to get the "multicontroller" branch in my test setup (8 x HRE92, opentherm)

[DanD]

OK great. I'd forgotten that you'd originally posted about the multi-controller branch, sorry. Hopefully my previous post gives you the info you need to configure the HGI80 in Domoticz once you've got the branch successfully installed.

PS I found it a real pain to program up the JavaScript (as I've little or no experience in JavaScript) to ensure that the hex device ID makes it all the way through to the Evohome code. Hopefully it all works OK for you. Let me know how you get on.

Good luck!

Dan

[rogerrabbit]

Compiled succes and sudo reboot.
But no multicontroller functionality...?
Not Sure what went wrong. Perhaps i still dont have the multicontroller branch?
Please shine a light on me ...
Cheers


Sent from my iPhone using Tapatalk

[DanD]

@rogerrabbit

Sorry for my delay in replying. A few thoughts:

Have you refreshed your browser cache? Most browsers won't pick up the user interface changes in the Javascript without a refresh. I've been caught out by this a few times whilst developing code and wondered where all my changes have disappeared to.

Did you install the multi-controller branch in a separate directory, but also leave the original Domoticz install in place? If so, the Pi might still be running the previous version as a service after the reboot. Type 'sudo service domoticz.sh status' to find out the location of the version running.

To be 100% sure that the git clone pulled the right version, have a look at Evohome.cpp in the hardware subdirectory and search for 'UserContID'. This is a new field which contains the controller ID.

Hope this helps.

Dan

[rogerrabbit]

@Dand,

edit - added a second evohome (my neighbours, or at least someone living nearby ). Looks like they coexist now without much issues in the domoticz environment... Which triggers an important security issue... Do you really want to have the functionality to report all devices that the HGI80 picks up?
I could imagine that my neighbour doesnt want me to control his heating system... perhaps the code should always request the controller code before displaying anything?


Hi Dan, I can report success. Recompiled this evening and verified the correct branch was running. I have just now added my evohome controller and am waiting for the devices to show up. They already started trickling in.
Is there anything you want me to check, test?

Cheers,
Roger

[DanD]

Thanks for the update. I'll have to check exactly how this version was meant to function as it's a few months since I did the main development work. I agree about your comments about potentially accessing a neighbour's system. What I think was meant to happen was that only devices bound to the controller ID you provide should show up in Domoticz. At the moment this only filters out other Evohome systems, so other Honeywell systems may still mess it up. Is it picking up another Evohome controller? Could you PM me a screenshot of the devices list? This should give me some idea what might be going on.

Dan

[thecosmicgate]

Also trying to implement the HGI80 together with the Itho Spider thermostate .

Getting this error :

Code: Select all

Error: evohome: ACTUATOR_STATE: Error decoding command, unknown packet size: 6
Error: evohome: unable to decode payload for command 3ef0

Is there anybody who can help me further to use / implement the Itho Spider ?

[DanD]

Hi,

I've had a quick search for information on the Itho Spider and I don't quite understand how you're trying to use the HGI80 and Domoticz to communicate with it. The HGI80 is only designed to communicate with the Honeywell Evohome system. Do you also have an Evohome system that you're linking up? Could you give me a few more details of the devices that you are trying to link up in Domoticz and I'll see if I can help.

Dan

[thecosmicgate]

Hi,

I've had a quick search for information on the Itho Spider and I don't quite understand how you're trying to use the HGI80 and Domoticz to communicate with it. The HGI80 is only designed to communicate with the Honeywell Evohome system. Do you also have an Evohome system that you're linking up? Could you give me a few more details of the devices that you are trying to link up in Domoticz and I'll see if I can help.

Dan

Hello Dan,

First thnx for the verry quick reply.
The Itho Spider (base ) : https://webshop.ithodaalderop.nl/produc ... openthermr
Is compatible with OTGW, and when you buy this thermostate with the additional gateway , this package has the HGI80 inside : https://webshop.ithodaalderop.nl/produc ... openthermr
So i started e-mailing with the Itho support and the send me the Spider base with the HGI80 , because i dont use the gateway ( Domoticz suposed to be the gateway)
Hope this is the answer you're waiting for , and can help me