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Opentherm Monitor based on a JeeNode

Posted: Tue Feb 28, 2012 12:41 am
by Digit
Hi,

I've been heavily involved in Opentherm the last couple of weeks and today I reached a point where I can see light at the end of the tunnel again :D

I've built an Opentherm Monitor based on the good-old Elektor Opentherm Monitor article (http://www.hekkers.net/files/Opentherm.pdf) and modified it so I was able to connect it to a JeeNode.
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But it didn't work as expected: decoding the Manchester signal resulted in too much errors on the JeeNode. Caused by different boiler and/or thermostat manufacturers all having their own timing issues, is what I can conclude so far...
So I went for another approach to decode the Manchester signal in a more 'adaptive' way and it paid off! No more errors. So if you ever want to build your own Opentherm monitor, this can be an interesting read:
http://blog.hekkers.net/tag/opentherm/

Re: Opentherm Monitor based on a JeeNode

Posted: Tue Feb 28, 2012 12:49 am
by Mdamen
Nice one! I like the way you "pit bull" into things, never giving up!

Re: Opentherm Monitor based on a JeeNode

Posted: Tue Feb 28, 2012 1:30 am
by Digit
Thanks Maarten,
Right, as long as I have the feeling that it can be done, I keep on digging :wink:
You know, with what I've learned in this project, I'd love to give Honeywell Evohome a 2nd try... oh well, maybe next winter :lol:

Re: Opentherm Monitor based on a JeeNode

Posted: Tue Feb 28, 2012 10:18 am
by Bwired
great!