Hi Marcus, all my temp sensors are ds1820s, and it is indeed a mixed star topology, but well within the limits of what Dallas suggests (cat5e based). So this could well be the same issue you had.
If so what is the best way to get to the bottom of this? How do you suggest I find out what's going on inside owfs? Cheers, Doma On 09/13/2010 10:15 AM, Marcus Priesch wrote: > Hi Guys (and Dolls) ;) > > i am running owfs in a couple of installations: > > my home heating system - couple of ds1820's and ds2406's connected to a > mixed star/bus topology (~20-40 meters) connected via ds9490B, > controlled by a cron job running every minute reading temperature values > through owpython and setting the switches ... it occasionally fails with > different errors - even a few times a day ... > > kernel: 2.6.31-gentoo-r6 > owfs: 2.7p21 > > which all in all is fine for me ... as i dont have "hard real time" > constraints ;) > > > the other installation is a weather station with a pcb holding a ds2490 > usb-1wire converter connected to a via epia me6000 motherboard using the > internal usb plug. the pcb is designed according to ds2490 datasheet. > > on the pcb resides a ds2450 adc, ds2406p (switch + memory) and a ds2408s > (8bit pio). > > this setup worked very well ... until i added two ds1820 to the pcb in > star topology with ~15meters cabling ... then it was random > stability ... until i added the "1wire long cabling" parts, which got it > to perform better - and on the software side i also added bus scanning > multiple times in case of failure ... > > however, currently i have an all new setup (new me6000, new ds2450 > board) which quits its job every couple of minutes with usb transmission > errors which i havent debugged yet ... googling tells me that there is > could be some usb impedance mismatch - but its exactly the same setup as > on the other systems which perform equally good ... > > hmmm ... so ... thats my experience with 1wire ... > > it's easy to setup, it's cheap, but it's not high availability ... i am > now also testing the ibuttonlink adapter to find out if there are better > solutions than the original dallas equipment ... > > for the weatherstation i also considered using the ds2409 microlan > couplers to connect the different ds1820's to improve the situation (has > anyone here gained experience using them ?!?!) > > however, as they are marked as "not considered for new designs" and hard > to get directly from dallas i didnt try them. as the design was finished > i found www.fuchs-shop.com which sells them here in europe ... ;) > > ... and now i am in the progress of redesigning everything ;) - one > usb-1wire converter per one ds1820 ;) > > well thats it ... > > btw: any suggestions on how i could improve my overall experience are > very very welcome ;) > > regards, > m. > > > > ------------------------------------------------------------------------------ > Start uncovering the many advantages of virtual appliances > and start using them to simplify application deployment and > accelerate your shift to cloud computing > http://p.sf.net/sfu/novell-sfdev2dev > _______________________________________________ > Owfs-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/owfs-developers > > ------------------------------------------------------------------------------ Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing http://p.sf.net/sfu/novell-sfdev2dev _______________________________________________ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
