[OpenTRV-interest] Frequent non-communication periods between hub and its valve

Sat Apr 25 12:31:40 BST 2015


I have been monitoring this issue, resetting, relocating OpenTRV's to try to determine the cause for quite some time now.

Replaced batteries - no noticeable improvement.

 (still ~3m) - possible improvement BUT now truly limited number of 
location options which does not bode well given this is not the intended
 final location and I expect that location to be far more limited.

HOWEVER recently

Noticed that my OpenTRV/FHT8V id's are @2532 (hub) and @1F2A (leaf).

 my limited understanding of OpenTRV's operation the id's 3 lsb are thus 0x2 (0b010) for both 
FHT8V and thus they are both running on the same timing cycle which with
 slight timing errors means their timing loops will likely be very 
slowly slipping past one another and thus transmitting to their 
respective FHT8V's for significant periods both in phase and out of 

This may explain a lot of what I have/am seeing as 
transmissions repeatedly interfere with one another thus practically 
preventing communication for significant periods depending on the 
physical location of the individual elements. Thus the hubs FHT8V losing
 synch and poor comms from OpenTRV leaf to hub.

I have observed 
this in the hub output I have monitored and captured (timestamps at the 
hub certainly would have saved a massive amount of time).

Thus to
 a certain extent I may just have been unfortunate that the two FHT8V's I
 have can cause the OpenTRV transmissions to interfere. Nonetheless the 
scenario is a very practical reality for myself and others - any 

It does not explain all loss of comms from leaf to hub which I would suggest is still poor.

 am fairly certain that on two occaisions I saw the active radio section
 of the hub OpenTRV TOTALLY stop working though OpenTRV continued 
TOTALLY unaware. There seemed to be a TOTAL lack of any actual form of 
transmission or reception which continued until the hub was hard power 
reset. I cannot explain how this happened but by inference lack of Tx 
and Rx occurred at the same time; ANY form of Rx observed from the leaf 
ceased (though the leaf still communicated with its own FHT8V) and at 
the same time similarly the hubs FHT8V ceased to receive transmissions. I
 do not know what it is possible for OpenTRV to do to monitor for this 

Regards Gary

----Original Message----


Date: 28/03/2015 12:05


Subj: Re: [OpenTRV-interest] Frequent	non-communication	periods	between	hub and its valve


OK I have popped in some new alkline batteries at 3.21V (NOT in situ). I managed to do it without reseting the FHT8V.

I understand the all-in-one comment, but I still beleive that the FHT8V is an important part of the mix unless you are implying it may become unsupported?

I still beleive I have been seeing this problem for a very long while but because I was using modified software I did not see the point in reporting it. However, I still suspect the problem may be a synchronisation problem because I seem to remember that every now and then I hear a single beep from the FHT8V but because I have not been looking just before (or after) the beep I can't report what the FHT8V thought was going on.

Regards Gary

----Original Message----
Date: 28/03/2015 11:36
To: "Open, non-developer list for interested parties"<EMAIL ADDRESS HIDDEN>
Subj: Re: [OpenTRV-interest] Frequent	non-communication	periods	between	hub and its valve


OK, that’s interesting.  That seems pretty low to me, and may not be properly powering the receiver when it comes up.

NiMH (for example) probably has lower ESR and might in fact be better here for current spikes even though the low-battery indicator spends most of the time on.

Do you have fresh cells to pop in at least briefly as a test, of any chemistry to hand?

(I shall be
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