Arduino Forum

Using Arduino => Audio => Topic started by: Alcafuz on Jan 27, 2011, 06:29 pm

Title: Eletret for sound sensor.
Post by: Alcafuz on Jan 27, 2011, 06:29 pm
(SORRY ABOUT MY ENGLISH)

did someone know a good way to connect an electret to arduino??

i've tried differents ways that i find searching in google, but i think the difficult is the voltaje level, i would like to work with 5 v for the electret supply.

thanks. (and sorry again) 
Title: Re: Eletret for sound sensor.
Post by: Grumpy_Mike on Jan 27, 2011, 07:17 pm
http://interface.khm.de/index.php/labor/experimente/arduino-realtime-audio-processing/ (http://interface.khm.de/index.php/labor/experimente/arduino-realtime-audio-processing/)
This shows the basic audio connector, but you will need a pre amplifier to get the voltage up to 2.5v peak to peak in order to get the maximum swing into an arduino. Google for a circuit.
Title: Re: Eletret for sound sensor.
Post by: Alcafuz on Jan 28, 2011, 03:44 am
Hi Grumpy_Mike, thank for answer..... that's what i'm looking for, a good preamplifier or amplifier that give a good signal to arduino.

I've tried with 386 circuit, but the sensibility is too poor.


(http://sirbot.org/sirbot-modules/sound-sensor/lm386_preamp_schematics.jpg)

Title: Re: Eletret for sound sensor.
Post by: Arduinoid on Jan 28, 2011, 04:08 am
Hey Alcafuz,

I just finished writing code for using an electret with an Arduino.  I posted my code in the topic about music detection.  I use a 386 to amplify the signal first and it is just enough, more amplification would be better but would also be more expensive, so I made the code do the work.  Let me know if you have any questions about it.  Also when I was looking up specs on electret microphones most suggested low voltages around 2V so I used the 3.3V power with a resistor to power it, I don't know what my specific model mine is, it just came with a box of random electronics, but it seems to work well.
Title: Re: Eletret for sound sensor.
Post by: Alcafuz on Jan 28, 2011, 03:25 pm
Hi everyone, thanks for answer, I'll try your suggestions and post the results.

Title: Re: Eletret for sound sensor.
Post by: joker on Feb 09, 2011, 06:52 pm
You may try this one too which was designed and optimized for Arduino http://didier.longueville.free.fr/arduinoos/?p=1057 (http://didier.longueville.free.fr/arduinoos/?p=1057)
HTH
Title: Re: Eletret for sound sensor.
Post by: Alcafuz on Feb 10, 2011, 12:40 am
thanks, i will try to probe it.
Title: Re: Eletret for sound sensor.
Post by: jumanji on Feb 15, 2011, 12:27 am
You might also consider using this mems-based microphone module from sparkfun: http://www.sparkfun.com/products/9868.  This module has the mic mounted and it runs from 3.3V and outputs a 1.65V signal with no audio input.  The output will range from 0V to Vdd with loud sounds so it can easily be used with the Arduino ADC.