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Shawn Lowe
09-19-2008, 01:22 AM
Hello everyone-
This question is primarily directed for Tracy Allen, but perhaps others can chime in and answer. I am working with a DS1620 and want to put it into One-Shot mode for a higher accuracy from the chip. On EME's website, Tracy mentions:

Also, the first time you send the $03 command to the stamp, you have to cycle the power to the DS1620 off, and then on again before the change takes effect. (IMPORTANT. I learned that last little tidbit after some hard head scratching!)

I have seen a program in StampWorks by Jon Williams that also sets the Mode into One-Shot, but he doesn't cycle power. In addition, there is nothing in the Datasheet to indicate a power down is required.

Can anyone confim a powerdown is required?


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Shawn Lowe


When all else fails.....procrastinate!

Chris Savage
09-19-2008, 01:25 AM
Shawn,

Running the code and wiring up the experiment would probably answer that question. ;)

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Chris Savage
Parallax Engineering

Tracy Allen
09-19-2008, 01:47 AM
Hi Shawn,

I wrote those observations quite a while ago and haven't had occasion to retest it in the interim. Like Chris says, you can test it for yourself and please report back. I might have gotten it wrong, or Dallas might have changed the operation.

One more comment is that since I wrote that page, Dallas Semi has revised the way DS1620 handles the counts remaining registers. Those are used to extend the resolution past 9 bits. It used to be that it returned a one part in 128 value, but they changed it to one part in 16. That does not alter the algorithms needed to get at the higher resolution, though.

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Tracy Allen
www.emesystems.com (http://www.emesystems.com)

Chris Savage
09-19-2008, 03:12 AM
Tracy reminded me…Dallas did make a change to the DS1620 at some point. I can’t remember the exact details, but there was a change.

[Edit] - It seems at least one change was to increase the supply voltage range.· Sorry I can't find more info, so definitely post your results here.

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Chris Savage
Parallax Engineering


Post Edited (Chris Savage (Parallax)) : 9/18/2008 7:25:59 PM GMT

Shawn Lowe
09-19-2008, 03:58 AM
:)
I certainly will report back tonight.
Thanks Tracy & all

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Shawn Lowe


When all else fails.....procrastinate!

Beau Schwabe
09-19-2008, 06:08 AM
The Changes made to the DS1620 were in relation to the high resolution temperature mode...

Taken from this thread... http://forums.parallax.com/showthread.php?p=606317


Note: The DS1620 RevD implemented a proprietary temperature sensing architecture using dual slope convergence method to determine temperature.
The DS1620 RevE implements a commonly used bandgap reference with sigma-delta ADC approach to determine temperature.

Attached is a file I received directly from Dallas Semiconductor/Maxim noting the difference between RevD and RevE version of the DS1620


Attached file·-> http://forums.parallax.com/attachment.php?attachmentid=44280




Here is another thread that might be helpful...· http://forums.parallax.com/showthread.php?p=608042





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Beau Schwabe (mailto:bschwabe@parallax.com)

IC Layout Engineer
Parallax, Inc.

Post Edited (Beau Schwabe (Parallax)) : 9/18/2008 10:19:24 PM GMT