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
