Hello Paul, is there a way I can test the "Skip ROM" option you mention?
I found this in the DS18B20 Datasheet on page 5: ---------------------------- In some situations the bus master may not know whether the DS18B20s on the bus are parasite powered or powered by external supplies. The master needs this information to determine if the strong bus pullup should be used during temperature conversions. To get this information, the master can issue a Skip ROM [CCh] command followed by a Read Power Supply [B4h] command followed by a “read time slot”. During the read time slot, parasite powered DS18B20s will pull the bus low, and externally powered DS18B20s will let the bus remain high. If the bus is pulled low, the master knows that it must supply the strong pullup on the 1-Wire bus during temperature conversions. ----------------------------------- What would be the "some situations"? Can I tell the master, that the slaves are powered? How do you (in owfs) figure out if the slaves are parasitically or externally powered? Won't a slave be not "upset" when we treat it powered and it is powered, but it thinks its not? Obviously they are fine being treated "parasites" when in fact they are powered. My best regards, Martin Patzak ------------------------------------------------------------------------------ _______________________________________________ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
