maybe it works with cached version, not uncached 2011/2/5 patyrk <[email protected]>: > Hello > Fist, sorry for double messages. My e-mail client went nuts. > > I previously said that simultaneous temp. conversion is not possible > with parasite power. Well, I was wrong. This mail is to sum up all that > wrote before. > > The specs of ds18b20 aren't very clear about it. However there is a > command skip rom mentioned on page 11 > > SKIP ROM [CCh] > The master can use this command to address all devices on the bus > simultaneously without sending out > any ROM code information. For example, the master can make all DS18B20s > on the bus perform > simultaneous temperature conversions by issuing a Skip ROM command > followed by a Convert T [44h] > command. > > Moreover I asked about this simultaneous conversion on some Polish uC > board and 2 users replied that they use this feature and it works even > with parasite power. So I thinks it would be nice to have this feature > working in owfs because its very useful with many ds1820. > > I've found some messages form 2006 and 2008 on this list that say > simultaneous is working. But it seems not to work in my case. I use > ds2480b master connected to serial port and few ds18b20 and 2 ds18s20. > > Maybe I'm using it wrong. This is my script > #!/bin/sh > owwrite -s 2485 /simultaneous/temperature "1" > > temp="temperature" > owread -s 2485 patryk/"$temp" > owread -s 2485 pokoj/"$temp" > owread -s 2485 pokoj_grzejnik/"$temp" > owread -s 2485 korytarz/"$temp" > owread -s 2485 korytarz_grzejnik/"$temp" > owread -s 2485 tata/"$temp" > owread -s 2485 dziadek/"$temp" > owread -s 2485 zielony/"$temp" > > echo "koniec" > > > It takes about 10 seconds no matter if I use simultaneous. > owwrite takie about 0.02 seconds that's to short. > > > -- > p4trykx > > > > > > ------------------------------------------------------------------------------ > The modern datacenter depends on network connectivity to access resources > and provide services. The best practices for maximizing a physical server's > connectivity to a physical network are well understood - see how these > rules translate into the virtual world? > http://p.sf.net/sfu/oracle-sfdevnlfb > _______________________________________________ > Owfs-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/owfs-developers > >
-- Roberto Spadim Spadim Technology / SPAEmpresarial ------------------------------------------------------------------------------ The modern datacenter depends on network connectivity to access resources and provide services. The best practices for maximizing a physical server's connectivity to a physical network are well understood - see how these rules translate into the virtual world? http://p.sf.net/sfu/oracle-sfdevnlfb _______________________________________________ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
