On Sun, 25 Aug 2002, Fredrik Axtelius wrote:

>Hi!
>
>I have a National LM35CZ (Precision Centigrade Temperature Sensor) connected to AN0 of my 16f877.
>When looking at the values with my DVM on the output from the LM, everything is stable. Putting a voltage divider pot on AN0 and reading the values, everything is great.
>
>However, putting the LM35 on AN0 and reading make the values kinda "fuzzy".
>Normal room temepratur should give me something like 50 from AN0 which is what I get sometimes, the problem is that reading AN0 over and over, the value I get pend from 47 to 55.
>
>I thought the LM35 couldn't devliver enuff ampere so I put a LM324 between it an AN0, same result.
>
>Im a newbie, did I miss anything?
 Check your grounds and add a decoupling capacitor across the LM35 pins.
Use a shielded lead if it is longer than ~30cm. You can also make the
LM324 buffer a lowpass by changing the feedback network.

Peter

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