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Author Topic: DS18B20 wrong connection  (Read 1494 times)
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Far, Far East
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I've tried to connect this thermometer to Arduino Duemilanove like there http://stuff.nekhbet.ro/2009/08/23/how-to-use-the-ds18s20-and-ds18b20-temperature-sensors-with-arduino.html, and used program from there (first listing )http://tutorialpedia.org/tutorials/Working+with+Dallas+DS18S20+and+DS18B20+temperature+sensors+from+Arduino.html, but it doesn't find thermometer.
That's the way I connect it (perhaps I'am wrong in some trinket):
http://saveimg.ru/show-image.php?id=631b3bf3a2e58c887e7b43b5ea4e372e
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Van Alstyne, TX
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You have incorrectly wired your 18S20.  See figure 4 on page 6 of the manual
for the DS18S20.   The Ground and Vcc pins need to be shorted together and
connected to ground.  The Data pin goes to the digital pin on the Arduino as
well as thru a 4K7 resistor to Vcc.

The diagram on stuff.nekhbet.ro is not completely correct.

   -Rusty-
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Far, Far East
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Sorry for stupid question, but what "Vpu" is?   
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Far, Far East
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It works. Thanks!
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Van Alstyne, TX
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Vcc is the positive supply voltage.   The 18S20 max's out at about +5.5-volts.
Glad you got it working!
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Far, Far East
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I know about "Vcc".
What's "Vpu"? Is "Vcc" the same thing?
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Van Alstyne, TX
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I've never heard of Vpu.  Where are you seeing this??   A little
context would helpful.
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Far, Far East
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At page 4 of DS18S20 manual (figure 4).
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Van Alstyne, TX
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Vpu is the pull up voltage supply used on the data line for "talking"
to the DS18S20.  Technically, it's not the same thing as Vcc but it
can be (well, in the spec' sheet, the supply voltage is Vdd, not Vcc).

Check out the DC Electrical Characteristics table on/about page 20.

    -Rusty-
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