Let's Make Robots!

using a microphone as sensor

I have a couple of headset microphones, and I would like to use them as sound sensors..

I tried to amplify the signal using LM386, but it doens´t work.. can someone help me on this?

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.
do you think this is a correct circuit? If I connect the output to the analog pin will it give me sound level?


As long as the mic is connected with the correct polarity you should get something if the processor samples the input at the right time. Depending on what your trying to detect some additional circuitry may be benificial.

If you want to sample sound then some amplification may be necessary. 

I tried this circuit, but no luck..  :-)

what I really would like to do, is to "read" an analog value according to the sound detected by the microphone..


You'll only get tiny voltage changes from the circuit above, need to amp it up some. Ok, maybe not that much, but maybe at least feed it to a transistor base to get a larger voltage swing.
I have just finished this circuit, wich seems similar to the one you posted but no luck again...  through the arduino output window I just get noizy values...

Missing a 10k resistor from the C6 10 uF cap output end to ground, to compare to the above mic circuit, gives the output some "wiggle". No wiggle, nothing to amplify. R1 in the mic circuit was also 2.2k, not 1k, but that difference might not change a lot.
Is it by chance too sensitive? Can you post some samples of what you are seeing? Sorry if you have already since I am at work pages load funky and images usually dont show at all.
I´m out of my bench for today, tomorrow I will post the results.. 

There is also something called acoustic triangulation. Which isnt really using a single microphone as a sensor, but using multiple microphones to detect things. I stumbled upon this extremely interesting write up, very informative, very intelligent, very long, very easy to understand. Maybe it could help you:




I didn't know, myself, that so much was involved in making one of these guys. 

very interesting project and inspiring, I was thinking in doing something similar but more simple, maybe it won´t be so accurate.. we´ll see the result  :)