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<pre>Spencer<br /><br />Not sure if the 'noise' is actually from the cct or the detection process.<br /> <br />We had some issues with the Arduino analog and false or noisy readings.<br />http://www.element14.com/community/thread/23967?start=15&tstart=21<br /><br /><em>It's a bit messy with the OP not exactly following the suggestions, but Message 21 onwards should show that the analog needs some time to settle.</em><br /><br />Not sure your code, but send me an email if you like.<br />I do have some audio peak hold circuits we used in lighting controllers, that worked well.<br /> <br />Mark<br /><br />
On Sat, 17 Aug 2013 22:57:09 +1200, Spencer Travers wrote:
> Hi all,
>
> I am working on a classroom environment monitor project with a group
> of intermediate students (11-13 year olds). One component of this
> project is a very basic sound level meter connected to an Arduino. We
> have tried a Freetronics microphone interface board (schematics
> at http://www.freetronics.com/products/microphone-sound-input-module
> [1]) with poor results. The module seems to be very noisy and the
> output appears to oscillate.
>
> We are essentially after a circuit to sample the background noise
> level and provide a 0-5 V output for the Arduino ADC to read. We are
> not too concerned about accuracy as the output will be a traffic light
> red/orange/green display. If the Freetronics module had worked as
> advertised it would have been ideal.
>
> Can anyone out there suggest a modification to the board we have or an
> alternative circuit?
>
> Spencer
>
> Links:
> ------
> [1]
> http://www.freetronics.com/products/microphone-sound-input-module#.Ug9RbZJ9t-0
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