LM34DZ says my shop is icy

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I'm a ds1620 fan but I'm working with an LM34(F) and ADC0831 to learn
more about A/D conversions with my Bs2. I've followed several
examples for code but I get .043 volts back. I've tried 2 different
LM34s, same thing. My reference voltage is just the Vss. It does
respond to temperature changes.

rheine@m...

Archiver

Sorry about the profile tag about fixing. Was a joke from a family
group.

--- In basicstamps@y..., "Could you fix this.....right now!"
<rick_heine@y...> wrote:
> I'm a ds1620 fan but I'm working with an LM34(F) and ADC0831 to
learn
> more about A/D conversions with my Bs2. I've followed several
> examples for code but I get .043 volts back. I've tried 2 different
> LM34s, same thing. My reference voltage is just the Vss. It does
> respond to temperature changes.
>
> rheine@m...

Archiver

For rick

I am using a TLC2543 with the LM34 and this woks for me.

The max voltage your ADC puts out is 4095 mv. If you are using Vdd as a
reference voltage, and if your Vdd is 5.0, then divide 5000 by 4095. You
will get approximately 1.22. Multiply the reading you get from the ADC by
1.22 and you should get an accurate temp reading. If you do the conversion
in your code you will have to convert 1.22 to hex. Your conversion formula
should look something like this:

RESULT = 64*0+256*/RESULT
RESULT = RESULT */$013D

The 64*0 seems silly but it is part of the code I got from Al Williams. Ask
him for the Owl.2 document. There are good examples of the code there.

Sid