Isn't that the converting temp error message?

-marc

On Mon, 11 Jul 2005, PicDude wrote:

> I've implemented some 1-Wire code to read a DS18B20 sensor using a PIC, using
> parasite power.  Still in testing on a breadboard, it sits there all day with
> 2 sensors on the bus reading ~28 deg C.  But periodically, perhaps once every
> few hours, I get an odd value of "85", or "-21" once interpreted from the
> DS18B20's format.  Seemingly important, this works out to B'10101010', and
> even more important is that it passes the checksum test.
>
> I can now reproduce this by removing the positive power from the sensor.  And
> it's always that magic "85".  Is there some significance to this, so that I
> can figure out how to determine it's bogus and not display 85?  I can't find
> any reference to this value or bit pattern being generated when power to the
> chip is lost or otherwise.  That it's passing the checksum test is really
> bothering me.
>
> Cheers,
> -Neil.
>
>
>
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