yes, well i think owfs is doing 1second wait time of pullup with serial-onewire dallas converter (i don't remeber it exactly i think it's ds2480b)
the question is... it's works but sometimes it work wrongly i was thinking something like... write alarm high temperature of user value to eeprom and to current memory change eeprom to uservalue+1 when device is reseted eeprom=current memory this time we know that device reseted and the 85 value is wrong it's ugly but since ds18b20 don't have a user bit to save information at eeprom... i think it's a solution (maybe not a good one) that remove 85 degree error Em 29 de fevereiro de 2012 23:17, Eric Vickery <[email protected]> escreveu: > Even if they are powered you have to make sure you are waiting long enough > before taking a reading > after a temperature convert. At 12bits the DS18B20 takes as long as the > DS18S20 (around 750mS). > > On 2/29/2012 8:12 PM, Roberto Spadim wrote: >> yes hehe my is the second, i connect 5v, 0v and owbus >> does ds18b20 have a crc or another feature that shows the reset status >> or something else? i could check for example.... >> read 85 degree >> read the crc value (or another reset value) >> start of infinite loop: >> read 85 degree again >> read the crc value (or another reset value) >> if crc value = reset value, loop, else good read >> >> i don't know if exists a reset counter or something like it in >> ds18b20, does anyone know? >> >> >> Em 29 de fevereiro de 2012 23:07, Eloy Paris<[email protected]> escreveu: >>> Hi Roberto, >>> >>> >>> On 02/29/2012 08:31 PM, Roberto Spadim wrote: >>> >>>> hi guys, i'm having a lot of problem with ds18b20 and 85 degree reads >>>> what are every body doing when this occur? >>>> today i read to times when this occur, and if it's 85 em both i allow 85 >>>> degree >>>> anyone know another good solution? >>> >>> If parasitic powered make sure that Vdd is connected to ground instead of >>> leaving it floating. If they are being powered then I am afraid I don't have >>> a good suggestion :-( >>> >>> Cheers, >>> >>> Eloy Paris.- >>> >>> >>> >> >> > > ------------------------------------------------------------------------------ > Virtualization & Cloud Management Using Capacity Planning > Cloud computing makes use of virtualization - but cloud computing > also focuses on allowing computing to be delivered as a service. > http://www.accelacomm.com/jaw/sfnl/114/51521223/ > _______________________________________________ > Owfs-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/owfs-developers > -- Roberto Spadim Spadim Technology / SPAEmpresarial ------------------------------------------------------------------------------ Virtualization & Cloud Management Using Capacity Planning Cloud computing makes use of virtualization - but cloud computing also focuses on allowing computing to be delivered as a service. http://www.accelacomm.com/jaw/sfnl/114/51521223/ _______________________________________________ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
