Excessively high reading from TMP36

General
1

Hi,

I was tinkering around with the core and playing with some of the examples and the one with the TMP36 sensor is giving me some odd return values.

I’ve got 3 of the sensors (all giving a reading within 1 degree of each other) but with a plain vanilla setup as in your demo I’m getting a mv reading of ~ 1291 which is 55 degrees celcius? I’ve tried a couple of the other analog pins but not joy - any thoughts/pointers?

Thanks,

Chris

2

Already solved here: https://community.spark.io/t/odd-analog-readings

Put the 0.1uF cap from analog pin to gnd, as close as possible to the TMP36,
and everything will be fine.

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3

Thanks very much for that - very informative and helpful

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4

You’ll want to keep the capacitance limited to 0.01uF max, due to some restrictions listed in the TMP36’s datasheet. Some have tried the 0.1uF without problems, but if you can find a “103” 0.01uF, it would be good to.

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5

All looking good now - again. Appreciate the help.

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