Thanks for your full information...you know all about electronics...

Miguel

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> De: Wagner Lipnharski <wagner@USTR.NET>
> Para: PICLIST@MITVMA.MIT.EDU
> Assunto: Re: PIC WITH DS1621
> Data: Sexta-feira, 14 de Janeiro de 2000 14:58
>
> Hi Miguel,
> If by accident or error the ISHOT programable bit is set to "1" the unit
> will stop conversions.
>
> Considering that your 2 wire communication protocol software is working
> nicely (SCL max around 100kHz), and the bus is not busy by any other
> reason, the unit could be deffective if the problem is intermitent.
>
> If you don't have a I2C protocol analyser to make sure about what is
> happening at the interface, or a good software analyser, then it is
> better to recheck your software.
>
> If by any error, the "STOP Convert T" command is issued, the unit will
> also stop conversions.
>
> What happens if you issue a "START Convert T" command when the unit stop
> conversions? If it restart it means that by any reason it was stopped by
> command.
>
> The "Read Temperature" command (hexa AA), in some bit shifted/drop
> and/or marginal timming situations can be received as "hexa 22" that
> means "Stop Convert"... so, check protocol software timmings.
>
> I use 1621 and 1629 for long without any problems at all (with 8051).
>
> I am pretty sure you have it, but for the others:
> http://www.dalsemi.com/DocControl/PDFs/1621.pdf
> and make sure to read page 15, "NOTES".
>
> Wagner Lipnharski.
>
>
> WF wrote:
> > Hi,
> > We did a project that we measure the temperature using the I2C DALLAS
> > DS1621 Sensor, using the PIC...
> > Sometimes the SENSOR stops the measure the Temperature, the PIC doen't
> > stop to send the I2C commands for Sensor....
> > Can the DS1620 STOP to measure? Can i reset it? Is the some noise?
> > Miguel Wisintainer