Hi David,
1. Memory: That memory consuption sounds excessive (there is very little
memory used by owfgs -- less than 1 MB. It's sometimes hard to tell what
actual memory consumption is under linux -- the system doesn't scavenge
allocated memory until it's needed. We've tested owfs under valgrind for
memory leaks, but it's always possible.
2. owperl vs shell script. This is more a matter of convenience. Shell
scripts have a modest start/stop penalty while the owperl can run an
internal loop. owperl doesn't need the file system (FUSE). You can configure
a bunch of ways:
A. owfs/FUSE and shell cat/echo/...
B. owfs/FUSE and perl file read/write
C. owserver and owshell (owget/owwrite/owdir)
D. owserver and OWNet.pm (perl)
E. owserver and 'owperl -s 4304'
F. owperl: OWIinit('-u')
Personally, if I wanted the extra flexibility of a perl program (to remember
values, do calculations, etc) I'd probable do "D" above. If I liked shell
scripting, I'd choose "A" or "C"
3. Temperature reading pause. It turns out that during a temperature
reading, even with external power, the DS18X20 cannot tolerate other bus
activity. If your temperature values don't change quickly, you can increase
the "volatile" cache time to incur the reading penalty less frequently
(giving stale data, perhaps).
Anoth approach is to add a separate bus master, and a put the temperature
sensors on a separate bus. owfs will happily aggregate the two, and not
stall the switches for temperature readings.
Paul Alfille
On Fri, Mar 20, 2009 at 6:47 AM, david schumacher <davids...@web.de> wrote:
> hello together!
>
> this is my first post to this list.
>
> i stumbled upon owfs (great stuff, thanks!) while searching a simple way
> to measure and control temperatures.
>
> i am using DS9490R (bus master) with two DS18S20 (thermo), two DS2401
> (serial) and one DS2413 (two channel switch) for testing.
>
> after running this shellscript 24 hours (heavily switching the DS2413):
>
> --snip--
> r...@piano:/opt/1wire/uncached/3A.1EDA01000000# while true; do echo 1,1
> > PIO.ALL; echo 0,1 > PIO.ALL; echo 1,0 > PIO.ALL; echo 0,0 > PIO.ALL;
> echo -n x ; done
> --snap--
>
> and this in parallel (reading cached temperatures from DS18S20):
>
> --snip--
> r...@piano:/opt/1wire# while true; do echo $(date +%s; echo -n " "; cat
> 10.353E9C010800/temperature) >> /var/tmp/10.353E9C010800.temperature;
> echo $(date +%s; echo -n " "; cat 10.748570010800/temperature) >>
> /var/tmp/10.748570010800.temperature; sleep 8; done
> --snap--
>
> the memory consumption of owfs was about 955Mb virt / 816Mb res, and
> still growing.
>
> owfs was mounted using: r...@piano:/opt# ./owfs/bin/owfs -uall 1wire
> owfs and libow version is 2.7p17 .
> configure-flags: --enable-owperl --enable-debian
> kernel: 2.6.27-11-generic #1 SMP Thu Jan 29 19:28:32 UTC 2009 x86_64
> (ubuntu 8.10 amd64)
>
> did i make a mistake, or is there a problem in owfs?
>
> by the way: do you recommend me to use owperl instead of owfs when
> stability is the main concern?
>
> another ting:
> is there a possibility (in the 1wire-protocol in general and with owfs)
> to avoid the "blocking" of the whole bus for all other communication for
> one second while sampling temperatures using DS18S20?
>
> im thinking of "please start sampling, i will ask for the result later".
>
> this would be very nice when for example switching a heater via onewire
> while using the same bus with many slow sensors.
>
> thanks a lot for your patience ;)
>
> greetings from germany,
> david
>
>
> ------------------------------------------------------------------------------
> Apps built with the Adobe(R) Flex(R) framework and Flex Builder(TM) are
> powering Web 2.0 with engaging, cross-platform capabilities. Quickly and
> easily build your RIAs with Flex Builder, the Eclipse(TM)based development
> software that enables intelligent coding and step-through debugging.
> Download the free 60 day trial. http://p.sf.net/sfu/www-adobe-com
> _______________________________________________
> Owfs-developers mailing list
> Owfs-developers@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/owfs-developers
>
------------------------------------------------------------------------------
Apps built with the Adobe(R) Flex(R) framework and Flex Builder(TM) are
powering Web 2.0 with engaging, cross-platform capabilities. Quickly and
easily build your RIAs with Flex Builder, the Eclipse(TM)based development
software that enables intelligent coding and step-through debugging.
Download the free 60 day trial. http://p.sf.net/sfu/www-adobe-com
_______________________________________________
Owfs-developers mailing list
Owfs-developers@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/owfs-developers