On Tuesday 12 July 2005 11:05 am, Ruben J=F6nsson scribbled:
> Yes, this is defined behaviour according to the datasheet.

I must be blind, cause I can't see anything about it.  I guess slap on my=
=20
wrist and I'll go re-read the datasheet.  And I still think it's silly to=
=20
default to anything that will pass the checksum.


> I don't write to the EEPROM. The whole idea is to make sure that the
> scratchpad is different from the EEPROM and if it is still different af=
ter
> a temperature conversion there has been no (power on) reset. Note that =
this
> is not the 1-wire reset pulse. You could also use the config register b=
ut
> then you must make sure that it is different from the value in the EEPR=
OM.
>=20
> But you still have to make sure that the value in the EEPROM is differe=
nt
> from what you are actually using (in the ram config register).

Correctamundo.


> Yes, it would make more sence to have a bad CRC for the temperature
> registers at power up before any temperature conversion is done. But I
> guess that the CRC is made on the fly and only appended after all other
> bytes have been sent.

Or default to something outside the normal measurement range -- like perh=
aps=20
127 deg C.

Cheers,
-Neil.


--=20
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