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Bad temperature readings with DS18B20

Posted: Saturday 10 October 2015 22:09
by machal88
I have a problem with reading temperatures if outside is below 0 degrees in Celcius via DS18B20.

If the temperature outside is under "0" everything is OK, in Domoticz values are OK also, but now at night on the normal thermometer is -2 degrees, but on Domoticz is "0" and gives in LOG Error: 1-Wire system : error reading value from /sys/bus/w1/devices/

If I check the status via command in SSH " /sys/bus/w1/devices/28-0115623756ff $ cat w1_slave" it shows correct values (ie. -1222), so I think there is a problem in Domoticz...

Could you please give me some advise on this case? I will be very grateful ;)

EDIT: after update to newest beta version of Domoticz it's working OK, but next problem occurs - this time with scripts - switches over gpio/433mhz... they doesn't work...

EDIT #2: working after adding "///" (3 slashes) before script :D

Re: Bad temperature readings with DS18B20

Posted: Sunday 11 October 2015 8:50
by Jastrzi
machal88 have a same problem. Just noticed the readings below 0 degrees starts failing and Domoticz does not show values below 0.

Domoticz Team, are you planing to release the stable version soon or I need upgrade to BETA?

Re: Bad temperature readings with DS18B20

Posted: Sunday 11 October 2015 13:28
by gizmocuz
a stable will be published when it is ready (and not now... waiting for some changes first)

To answer your question, update to the stable indeed!

Re: Bad temperature readings with DS18B20

Posted: Monday 12 October 2015 10:49
by makuta77
Hi,
I have exactly the same error in version 2.2563.
Need a workaround for this problem please...

Best Regards

Re: Bad temperature readings with DS18B20

Posted: Monday 12 October 2015 20:43
by machal88
Hi @makuta77

You just need to update your Domoticz to the latest beta (i.e. V2.3295), this will solve the problem :)

To update Domoticz from your version or below type via SSH or at the terminal on Raspbian:

Code: Select all

1. cd domoticz
2. wget http://domoticz.sourceforge.net/beta/domoticz_linux_armv7l.tgz
3. tar xvfz domoticz_linux_armv7l.tgz
4. rm domoticz_linux_armv7l.tgz
5. sudo service domoticz.sh restart
Please let us know if this solution will work for you :)

Re: Bad temperature readings with DS18B20

Posted: Wednesday 14 October 2015 13:55
by popunonkok
I have the same problem aswell...
In Domoticz it flatlines at Zero degrees. But if i look at my RDDtools graph it shows below zero.
Its feels especially bad because where I live the temperature is just starting to drop below zero in the nights witch is kind of interesting to Log.

@machal88 : The problem with your solution is that i guess it could bring along other kind of problem since it is the Beta version. Im not interested in the Beta because I want my system to be as stable as possible.

Really looking forward to the next stable version.

Re: Bad temperature readings with DS18B20

Posted: Wednesday 14 October 2015 15:23
by makuta77
Hi,
I agree with @popunonkok that install beta version is not a solution. I thing we need a patch or something for stable version to display temperature correctly.

For that moment i don't want to install beta version.

Re: Bad temperature readings with DS18B20

Posted: Friday 20 November 2015 15:34
by eriksson25
Hi, just wanted to say that I had the same problem, did the upgrade to beta version and it works now. Its my small system so its ok if its not 100% stable.

Re: Bad temperature readings with DS18B20

Posted: Wednesday 25 November 2015 7:54
by makuta77
Hello,
In my system upgrade to beta version resolved the problem and it is quite stable :)