DS18S20 Caution
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I ordered a couple of DS18S20 1-Wir3 Theremometer chips and received a
from that had to be signed in order to receive them. In essence, the
form stated that the DS18S20 (and DS18S22) was not compliant with
their descriptions. The error is rather disturbing. It seems that
randomly at power on the chip can corrupt its EEPROM, including the
"set ponts" which are used to correct the temperature calculation,
which means that the chip will not conform to the stated 0.5 degree C
accuracy. They offer a couple of software "patches" (I haven't looked
at them) which show how to "restore" the cip to a 2 degree C accuracy.
I cancelled my order.
Russ
from that had to be signed in order to receive them. In essence, the
form stated that the DS18S20 (and DS18S22) was not compliant with
their descriptions. The error is rather disturbing. It seems that
randomly at power on the chip can corrupt its EEPROM, including the
"set ponts" which are used to correct the temperature calculation,
which means that the chip will not conform to the stated 0.5 degree C
accuracy. They offer a couple of software "patches" (I haven't looked
at them) which show how to "restore" the cip to a 2 degree C accuracy.
I cancelled my order.
Russ
Comments
"Thanks, but no thanks." I, for one, am using I2C parts in my projects
since it's a whole lot cleaner and there are far fewer issues than with
1-Wire.
-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office
Original Message
From: russranshaw [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=fFSTqk8_mmVi5nJY-VkSV3jzADXB8gHpYdNtAHgRll72GGPvEvKVQ2A55X_7RkYvuNKH_a8kZQ5KZwi2]home.rr@c...[/url
Sent: Wednesday, April 14, 2004 4:31 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] DS18S20 Caution
I ordered a couple of DS18S20 1-Wir3 Theremometer chips and received a
from that had to be signed in order to receive them. In essence, the
form stated that the DS18S20 (and DS18S22) was not compliant with their
descriptions. The error is rather disturbing. It seems that randomly
at power on the chip can corrupt its EEPROM, including the "set ponts"
which are used to correct the temperature calculation, which means that
the chip will not conform to the stated 0.5 degree C accuracy. They
offer a couple of software "patches" (I haven't looked at them) which
show how to "restore" the cip to a 2 degree C accuracy.
I cancelled my order.
Russ
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website for this and cam up empty handed. Do you have a link to this
errata? I use these in a few projects and was going to use more in
future projects. I guess I will switch to the MAX6674 instead.
Jason
--- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...>
wrote:
> Good idea. Our supplier sent that note to us as well and we said,
> "Thanks, but no thanks." I, for one, am using I2C parts in my
projects
> since it's a whole lot cleaner and there are far fewer issues than
with
> 1-Wire.
>
> -- Jon Williams
> -- Applications Engineer, Parallax
> -- Dallas Office
>
>
>
Original Message
> From: russranshaw [noparse][[/noparse]mailto:home.rr@c...]
> Sent: Wednesday, April 14, 2004 4:31 PM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] DS18S20 Caution
>
>
> I ordered a couple of DS18S20 1-Wir3 Theremometer chips and
received a
> from that had to be signed in order to receive them. In essence,
the
> form stated that the DS18S20 (and DS18S22) was not compliant with
their
> descriptions. The error is rather disturbing. It seems that
randomly
> at power on the chip can corrupt its EEPROM, including the "set
ponts"
> which are used to correct the temperature calculation, which means
that
> the chip will not conform to the stated 0.5 degree C accuracy. They
> offer a couple of software "patches" (I haven't looked at them)
which
> show how to "restore" the cip to a 2 degree C accuracy.
>
> I cancelled my order.
>
> Russ
>
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the
Subject
> and Body of the message will be ignored.
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
> This message has been scanned by WebShield. Please report SPAM to
> abuse@p...
today I ordered one (had to get over the $32 purchase limit to avoid
handling costs).
They came back and said that the manufacturer has pulled them off the
shelves and is no longer making them...at least not that chip name at the
moment.
Original Message
From: "jbirnsch" <jbirnsch@v...>
To: <basicstamps@yahoogroups.com>
Sent: Tuesday, April 20, 2004 1:17 PM
Subject: [noparse][[/noparse]basicstamps] Re: DS18S20 Caution
> I assume that this errata came direct from Maxim? I searched there
> website for this and cam up empty handed. Do you have a link to this
> errata? I use these in a few projects and was going to use more in
> future projects. I guess I will switch to the MAX6674 instead.
>
> Jason
>
> --- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...>
> wrote:
> > Good idea. Our supplier sent that note to us as well and we said,
> > "Thanks, but no thanks." I, for one, am using I2C parts in my
> projects
> > since it's a whole lot cleaner and there are far fewer issues than
> with
> > 1-Wire.
> >
> > -- Jon Williams
> > -- Applications Engineer, Parallax
> > -- Dallas Office
> >
> >
> >
Original Message
> > From: russranshaw [noparse][[/noparse]mailto:home.rr@c...]
> > Sent: Wednesday, April 14, 2004 4:31 PM
> > To: basicstamps@yahoogroups.com
> > Subject: [noparse][[/noparse]basicstamps] DS18S20 Caution
> >
> >
> > I ordered a couple of DS18S20 1-Wir3 Theremometer chips and
> received a
> > from that had to be signed in order to receive them. In essence,
> the
> > form stated that the DS18S20 (and DS18S22) was not compliant with
> their
> > descriptions. The error is rather disturbing. It seems that
> randomly
> > at power on the chip can corrupt its EEPROM, including the "set
> ponts"
> > which are used to correct the temperature calculation, which means
> that
> > the chip will not conform to the stated 0.5 degree C accuracy. They
> > offer a couple of software "patches" (I haven't looked at them)
> which
> > show how to "restore" the cip to a 2 degree C accuracy.
> >
> > I cancelled my order.
> >
> > Russ
> >
> >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the
> Subject
> > and Body of the message will be ignored.
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
> >
> > This message has been scanned by WebShield. Please report SPAM to
> > abuse@p...
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
> Yahoo! Groups Links
>
>
>
>
>