ds18s20 don't allow this... but ds18b20 could work :D what you think? Em 29 de fevereiro de 2012 23:33, Roberto Spadim <[email protected]> escreveu: > maybe the configuration eeprom register could help... > when we read with 9 bits we could change eeprom to 10 bits, set > current to 9bits execute conversion algorithm > the eeprom configuration never could be = current conversion bit, or > we know that device was reseted and the 85 degree is wrong > > there's a way to read eeprom value, and the current value? or ds18X20 > don't allow this? > > Em 29 de fevereiro de 2012 23:30, Roberto Spadim > <[email protected]> escreveu: >> 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 > > > > -- > Roberto Spadim > Spadim Technology / SPAEmpresarial
-- 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
