Connecting electret microphone to Atmega16

[Arnab Ray]

Hi everyone,

I am trying to connect an electret microphone to the ADC port (port A) of Atmel Atmega16. My aim is to light an LED when there is a sound.

I have directly connected the mic to the input port of the micro controller. But there is no voltage detection at the input, even after changing the potentionmeter value.

Please advice me how i should connect the mic to the micro controller. Also please tell the IC number of any pre-amplifier, if required...

The image of the connection made by me is shown below:

 

[sky_123]

The spec of the electret mic element should show you what kind of signal you will get out of it.
You'll need an amplifier (a single transistor amplifier will be sufficient, no need to use an IC).
BTW, you don't really need a microcontroller to light an LED when there is sound. I just googled for
"sound detector circuit" and there were plenty of circuits that can use just a single op-amp for example.

 

[Arnab Ray]

hey thanks for the help..actually its a project kind of thing..right now i am testing it on a led..but my final aim is to change the direction of motion of a bot on the sound of a clap or something like that...so i am using a microcontroller.

 

[BradtheRad]

Consider using a 10k resistor.

The aim is to use whatever is the average resistance of the microphone as it is operating. That's how to obtain maximum voltage swings.

The capacitor blocks DC, so that AC gets to the microcontroller input. However in this case you may get better results if the signal is riding a DC component. It depends on which comes through better: (a) some waveforms climbing above zero V, or (b) all waveforms traversing above and below a midway volt level.

To get sufficient voltage swing, you may still end up needing a pre-amp.