Opentherm Gateway

[rtenklooster]

I want to use the opentherm monitor software on my raspberry pi.
For as far as i know i need to download the armhf file.
I have raspbmc installed and working, but what do i need to do to start the program?
I have never heard of arm and ahf files before.
If someone could help me out i'm a happy person.

I tried opening it with double click, bash, python, unpacking etc etc. Google was not very helpfull either.

[hvxl]

I don't know if you need the arm or ahf version on raspbmc. For raspbian it's the ahf version. But basically you download the binary, make it executable and run it:

Code: Select all

wget -O otmonitor http://otgw.tclcode.com/download/otmonitor-ahf
chmod +x otmonitor
./otmonitor

[rtenklooster]

hvxl... youre my hero!
Had to chmod +x
Now its working.. tomorrow ill get my pic burner and then the fun starts. ( i hope )
Thanks again.

[fabian]

Hi Schelte,

It's great to see how this project has evolved since i've build my first gateway with your help. Instead of soldering and debugging for 3 days, the new design without xtal and the ability to upload new (debugging) firmware with otmonitor realy makes the gateway easy to build within 30 minutes.

As expected i'm having timing issues with my Intergas Prestige CW6 boiler. When the flame is on, i'm getting lots of Error 03's.

If i'm not mistaken, you've created a custom firmware for the P16F628 with different timings for Intergas boilers. Looking at the changelog, these adjustments where also made to firmware 3.0, which isn't publicy available anymore. Is a custom firemware still needed for Intergas boilers ?

[hvxl]

Fabian,

In the latest 4.0 alpha firmware versions (4.0a6 and above) I have relaxed the timing requirements the gateway imposes on the opentherm signal. It will now accept signals way outside the official specifications. This should be sufficient to handle the bad timings we measured on your Intergas boiler.

[rtenklooster]

So,
I got it working, but i have some problems.

My current setup is a ATAG A244EC Boiler and a Chromotherm Vision Modulation Thermostat.

I can read all communications and set outside aswell as tele temperatures.
But as soon as the boiler starts to heat.. shit happens. I start to get a lot of Error 01 and error 03 messages. Followed by T10383C00 Write data DHW setpoint: 60.00
Shortly after the start of the error messages my thermostat says: "geen communicatie" (No communication).

The only thing i can do is pull out the power supply of my gateway for several minutes. Then it's working again.

[fabian]

Thanks. gateway has been running withour errors for 7 hours.

[hvxl]

But as soon as the boiler starts to heat.. shit happens. I start to get a lot of Error 01 and error 03 messages.

You didn't indicate which firmware you are using. But since you mention seeing error 01, my guess is 3.4. I suggest you try 4.0a8. It is much more forgiving to equipment that doesn't quite follow the opentherm specifications regarding bit timings.

[hvxl]

Thanks. gateway has been running withour errors for 7 hours.

Excellent. Thanks for the confirmation.

[rtenklooster]

Just uploaded the latest firmware version and indeed.. it remains working.
Thanks a lot.

But a couple of new questions have arrived.
1. Is it usefull for you if i upload a log file to your website, so you can add a ATAG A244EC boiler to your sheet?
2. Since the last update setting a tele temperature is not working anymore. I double checked my thermostat, tt is enabled en before upgrading, it was working. For now i get a OK as reply but my thermostat (Chromoterm vision modulation) is not doing anything with it. Outside temperature is working btw.
3. Can you explain the value of msgID 0, the status?
Is the last digit before slash the on - or off value for the boiler? i cant find anywhere what the 8 decimal / 8 decimal values mean.
4. What does control setpoint mean?
5. I am getting a value : 1?5/10 for msgid 15. the question mark is a bit weird.

[hvxl]

1. The equipment matrix was initially intended for people looking to buy a boiler and/or thermostat so they can make a choice based on the messages supported by the candidates. But I also turn to it when I get a question about certain equipment. So any upload of a log file is much appreciated.
2. The Chromotherm Vision Modulation thermostat has two ways to remotely change the setpoint: Using a tele contact and via opentherm messages. I came to understand the opentherm method doesn't work if the tele contact has been enabled. But that would have been the case for both versions of the firmware. Did you enable the tele contact recently? Are you sure it worked with the old firmware? Did you wait long enough before concluding it doesn't work with the new firmware (it can take over a minute for the setpoint to change)? Do you have logs showing such an attempt (both versions of the firmware, if you have them)?
3. Before the slash is the high byte (master status), after the slash is the low byte (slave status). Look in the OpenTherm Protocol Specification v2.2 pdf (you should be able to quickly find it if you enter that as a search term in google) for the meaning of the individual bits. The next version of otmonitor will have an option to display details about bit flags in messages.
4. The control setpoint is how the thermostat indicates to which temperature it wants the boiler to heat the water in the central heating system. Again, for more details check out the OpenTherm Protocol Specification.
5. The gateway has a very simple subroutine to display single-byte decimal numbers. It assumes no value will ever be higher than 199. Apparently your boiler reports it has a maximum capacity of 255 kW. That's a bit much. Are you heating a medieval castle? The specifications of my boiler say it's only 31.2 kW.

[hvxl]

I am getting a value : 1?5/10 for msgid 15. the question mark is a bit weird.

Fixed in firmware 4.0a9.

[rtenklooster]

Thanks for your reply!
The pdf of opentherm was much of a help, thanks for that!
The only thing is, the status bits seem to be in the opposide order. bit 1 = 8 and 8 = 1

I will upload the new firmware this evening and report if it solves the problem.

And no, i dont own a castle haha.

It indeed tuned out the tele function should be disabled in order to work.
I have my php script / webapp working and communicating with my gateway

You guy(s) made me a happy men! I'll upload the logs later this evening.

* edit:"
I uploaded my log's to the website. I hope it contains some usefull information for you.

The new firmware solved the problem with larger values indeed. So that's fixed.
A in my opinion unlogical thing is the respons of the command PR=O
I would suggest you respond with PR: O=0 (zero) if there is no remote value set. Now it is responding with N, because you unset it with a zero, i would suggest you return it with a zero to. Now i have to replace the N with a zero in my script. It doesn't matter, just a small suggestion.

Edit 2:
I just noticed, if i insert the command: TT=16.50 it replies: TT: 16.50, if i request PR=O it also gives 16.50, but the screen on my thermostat says 16.0
I dont know if it was like that on older firmware versions, of if its a bug, or if the vision doesn't support override temps with half degrees.

[hvxl]

It's usual in computer science to count bits from right to left, starting at 0. So the bits are numbered 0 through 7, not 1 through 8 as you wrote. That way the value of each bit corresponds to the power of 2 of its number: Bit 0 = 2⁰, bit 1 = 2¹, bit 2 = 2², etc.

The PR=O command is supposed to return one letter indicating what type of override is in effect: T=temporary, C=continuous, or N=none. For the T and C case it also reports the requested setpoint. For N it doesn't really make sense to also report 0. (I just noticed there is a bug which makes the T/C indication unreliable. I will have to fix that.)

I would expect the Honeywell vision to handle half degrees. My thermostat does and it's an older model Honeywell thermostat. Did you allow enough time for the TT command to take effect? It can take some time before the thermostat requests a temperature override. If you have an override LED, wait for that to stop flashing and light up continuously. That is the indication that the requested setpoint has successfully been passed on to the thermostat.

Thanks for the logs.

[rtenklooster]

Ok thanks. It does makes sense

I re-checked it. If i send TT=19.50, the gateway responds with 19.50.
After a minure or so, the temperature shows up on the thermostaat.. only as 19.0
The room setpoint as reported by the PS=1 command reports 19.00
The override temperature as reported by PR=O returns 19.50

So i think we can conclude the temperature is succesfull send to the gateway but somehow it does not gets accepted by the thermostat?
I also checked it with the non beta firmware, and the result is the same.

Sending the outside temperature however is working the way it supposed to be, its displayed with one decimal precision.

I did not try to connect a led, because its clear it has received the TT. It shows a H symbol with a roof above it, and the thermostat temp had clearly changed ( from 16 to 19.00.
If you think it wil be of a help if i connect the led, just let me know.