Well this gets more curious. I am now measuring the time for each read,
reading type, power and latesttemp. Time for all is generally < 0.1
seconds, but then when I hit the slow loop the read for type is around
0.7 seconds, the others still < 0.1 seconds. I don't really need type
so I removed it and re-tested, on slow loops the power read is around
0.7 seconds, latesttemp still < 0.1 seconds. So I removed power as
well, just reading latesttemp, on slow loops that is now around 0.7
seconds. So it seems that at some point a sensor takes many times
longer for its next read, irrespective of which field is read.
I have now tested with 19, 11 and 2 sensors and the slow loop occurs
every 120 seconds. I am intrigued to know what causes this, any ideas?
Thanks
Mick
On 06/08/2020 10:23, Mick Sulley wrote:
OK I will log read times and see what that shows.
You say 'I also log if the error of the 1wire bus changes.' how do you
do that?
No I don't really need to read that fast, this is just a test setup to
get a better understanding so I can hopefully fine tune my main system.
There should not be anything else running. I just tried running top
at the same time, I monitored it at the point of the slow scan and
didn't see anything else significant.
Mick
On 06/08/2020 09:06, Martin Patzak wrote:
It looks like your timing has improved after all!
in your original Python-code you could time every read for each sensor.
I have also powered sensors and a read is usually faster than 0.1
seconds.
I log in a file if the read took longer than 0.3 seconds, which is
almost never the case.
I also log in the file if the whole reading loop took longer than 3
seconds, which again is almost never the case.
I also log if the error of the 1wire bus changes.
I read 25 sensors every full and every half minute, so maybe you
could implement a delay as well and see if things get more consistent.
Do you need to read so fast in a loop for you application?
What else is running on your machine? You could run top in parallel
to your python loop.
_______________________________________________
Owfs-developers mailing list
Owfs-developers@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/owfs-developers
_______________________________________________
Owfs-developers mailing list
Owfs-developers@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/owfs-developers
