You are most welcome Heimo. I am not Stefano, I am Martin - sorry for the misunderstanding.
Stefano is the author of pyownet. In my software I use python 2.7 and I have very consistent timing of reading 25 sensors in a loop every 30 seconds. Every second I read the status of two 8 bit I/O modules. I do use pyownet and I am very happy with it. The documentation of pyownet is pretty clean ;-) https://pyownet.readthedocs.io/en/latest <https://pyownet.readthedocs.io/en/latest/> On 13.03.20 19:17, zeitvertreib.wiss...@web.de wrote: > Thanks for the hint, Stephano! > > I had a version with sleep(1) and varying values after fw.close. I > got execution times between 1.65 and 2.2 s for a run. Longest > times at the first run. > > But you address the Python problem. Python2 is outdated, no longer > offically supported, but there are no libraries offically mentioned > for Python3. On installation I tried sudo apt-get install python3-ow. > It worked without errors. But I did not find a documentation of the > functions the library provides. For me, documentation is a mess. May > be a generation problem. > At the moment I'm happy with simple read an write operations in > to files provided at /mnt/1wire and subdirectories. > > Regards Heimo > > *Gesendet:* Freitag, 13. März 2020 um 18:26 Uhr > *Von:* "Martin Patzak" <martin.pat...@gmx.de> > *An:* "OWFS (One-wire file system) discussion and help" > <owfs-developers@lists.sourceforge.net>, zeitvertreib.wiss...@web.de > *Betreff:* Re: [Owfs-developers] How to Use Simultaneous > Hello Heimo, > > after writing to "simultaneous" you have to wait one second. > > For Python I would recommend you the library *pyownet *by Stefano Miccoli: > > > > The official OWFS bindings are > > - OW.py, based on SWIG wrapping the C API of libow > - ownet.py, pure python owserver client > > you will find both in debian packages > > - python-ow, https://packages.debian.org/buster/python-ow > - python-ownet, https://packages.debian.org/buster/python-ownet > > My advice is to avoid the use of these packages with python3 > (although python3 versions exist in debian) since they are not > actively developed. > > I’m the author of pyownet, a different package, which does not > belong to the official OWFS code base. It is documented at > <https://pyownet.readthedocs.io/en/latest/> and is available only > on pypi.org <http://pypi.org> since, to my knowledge, it is not > packaged by any major linux distribution. > > pyownet is actively mantained, and is perfectly compatible with > both python3 (up from 3.3) and legacy python2 (2.7 only). > > So if you “import pyownet” in your code you have to “pip install > pyownet”. The discussion in this thread is whether it is a good > practice to “sudo pip install pyownet” along the python packages > distributed by debian. In my opinion you should avoid this, and > instead use a virtual environment, as I tried to explain in my > messages. > > Bye > > Stefano > > > On 13.03.20 17:05, zeitvertreib.wiss...@web.de wrote: > > Hello Jan, > > I'm sorry, you are right. > I do not use bash commands, I do read and write operations from a > Python3 program. I do it step by step, as I'm not used to Python. > I had a version with uncached, but there was another program error > and I forgot adjusting the file path. > > PATH = "/mnt/1wire/bus.0/" > > *initiation of conversion:* > > while True: # Hauptprogramm > t1 = time() > fw = open(PATH + "simultaneous" + "/temperature", "w") > fw.write("1") > fw.close() > > > *reading values:* > > for i in tempList: > deviceFile = PATH + "uncached/" + temps[i] + "/latesttemp" > f = open(deviceFile, "r") > tempBuffer = float(f.read()) > f.close() > if tempBuffer != 85.0: > tempw[i] = tempBuffer > print(temps[i], tempw[i]) > break > t2 = time() > print(t2 - t1) > > However, now I wonder about very short conversion times, shorter > than 700 ms a single 12bit conversion shoul take. > > 1st run: > > 28.0A651B2D1901 26.625 > 28.0A35192D1901 22.875 > 28.0CB479A20003 21.75 > 28.8BE0182D1901 28.875 > 28.80A7112D1901 29.5 > 28.629B082D1901 22.75 > 28.953D062D1901 22.875 > 28.613079A20003 22.25 > 28.CF52142D1901 22.8125 > > 1.3515775203704834 sec > > following runs > > >>> %Run TempLesen.py > 28.0A651B2D1901 22.9375 > 28.0A35192D1901 22.9375 > 28.0CB479A20003 21.75 > 28.8BE0182D1901 23.125 > 28.80A7112D1901 23.125 > 28.629B082D1901 22.75 > 28.953D062D1901 22.875 > 28.613079A20003 22.25 > 28.CF52142D1901 22.875 > > 0.6546370983123779 sec > > no matter whether Thonny or Bash. > > Is there a Python3 library for RaspberryPi > > Actually there is a problem when installing OWFS on Raspian Buster > on PIs. File system an sensors appear in duplicates. I give you a > link to the forum of the manufacturer of the used DS2482-100 adapter: > > https://www.abelectronics.co.uk/forums/thread/303/owfs-duplicates > > Regards > H. Wissing > > > > Dr. med. habil. Dipl.- Ing. Heimo Wissing > Privatdozent, Arzt für Anästhesiologie, > Intensivmedizin und Schmerztherapie > Bioingenieur / Biomedizinische Technik > Neckarweg 1, 69118 Heidelberg > Tel.: 06221/801679 FAX: 06221/803738 > mobil: 0171/4571292 > > > *Gesendet:* Freitag, 13. März 2020 um 15:48 Uhr > *Von:* "Jan Kandziora" <j...@gmx.de> > *An:* owfs-developers@lists.sourceforge.net > *Betreff:* Re: [Owfs-developers] How to Use Simultaneous > Am 13.03.20 um 15:12 schrieb hwissing: > > Hello, > > > > I think one issue from the primary question is not answered.. > > > > /" If I read from '/temperature' then I get them read in much faster > > *but I don't get a fresh conversion each time."*/ > > > This is a very old question, and the mechanism has changed a bit > since 2008. > > > > > > > I have the same issue. First conversion with 8 DS18B20 sensors takes > > about 1 sec, immediately following requests take about 40 ms, but > > values are not updated. It takes a while till updated values are > > acquired, then conversion takes longer. > > > That is because you read /<ID>/temperature instead of > /uncached/<ID>/temperature > > But don't do this either. If you want simultaneos conversions, do > instead > > $ owwrite /simultaneous/temperature 1 > $ sleep 1s > $ owread /uncached/<sensor0id>/latesttemp > $ owread /uncached/<sensor1id>/latesttemp > $ owread /uncached/<sensor2id>/latesttemp > $ owread /uncached/<sensor3id>/latesttemp > $ owread /uncached/<sensor4id>/latesttemp > $ owread /uncached/<sensor5id>/latesttemp > $ owread /uncached/<sensor6id>/latesttemp > $ owread /uncached/<sensor7id>/latesttemp > > Latesttemp has the resolution of the previous non-simultaneous > conversion, or, after power-up of the sensor, the resolution set > in the > sensor's EEPROM. You can adjust the through /<ID>/tempres. > > See the manpage: https://github.com/owfs/owfs-doc/wiki/DS18B20 > > Kind regards > > Jan > > > _______________________________________________ > 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 >
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