Electronic – arduino – Self made microphone burns arduino

arduinomicrocontrollermicrophonesoldering

I'm very new to electrical engineering and I'm trying to read microphone input with arduino nano. I've made a separate microphone module (based on this example) and plugged it into aruino like this:

Unfortunately it was the last time my arduino was working. It's no longer displayed as a connection, and acts "randomly", so I think my microphone toasts controller for some reason. Here are some more pictures and a scheme of my mic module, could someone explain what am I doing wrong?

schematic

^{simulate this circuit – Schematic created using CircuitLab}

R1 – CR1/4W 10 (brown,black,black,gold)

R2 – CR1/4W 2KO (red,black,red,gold)

I have no education in electrical engineering, so I'm not sure about the corectness of this schema of units, just pasted what's written on the pack

Best Answer

I did this a very long time ago, so I might forget something. However, I'm almost completely sure I used resistors in the Kohm range.

After googling a bit I found this post, which might help you get a better understanding of how to use your microhpone.

However, I have noticed you intend to connect your microphone to the analog input of an Arduino. So remember to polarize the analog output to around 2.5V (maybe employing an Operational AMplifier to avoid distortion?) in order to avoid loosing part of your signal (if it is too close to 0V or 5V).

I have checked the circuit you provided. Indeed, it uses 10Kohm and 4.7Kohm to polarize the microphone.

That is, your Arduino gets fried because the 10ohm resistor draws relatively high currents (in the order of 500mA) which Arduino is not designed to handle.

I'm sure that once you replace your resistor your circuit will work fine :) Good luck!

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Arduino + Microphone how to grab values

If you are just trying to sample a microphone, then an Arduino might not be necessary. The computer has all of the tools required to sample and process data.

For example, if you have the data acquisition toolbox on MATLAB:

ai=analoginput('winsound');
addchannel(ai,1);
start(ai);
data=getdata(ai);

Or if you prefer something a little more free, you could use PyAudio, which is a simple way of getting audio off of your sound card and into an array of samples.

If you are dead-set on using the Arduino, you want to make sure that the output of your pre-amp is under 5V peak-to-peak, which you can check on an oscilloscope or multimeter. You then need to use a DC-block capacitor in series with the output of the pre-amplifier, and then shift the signal up to 2.5V using a simple resistor divider.

The effect that this has is biasing the entire signal up by 2.5V, so that it varies between 0 and 5V (the range of inputs for the Arduino).

After that, it is a simple matter of sampling the analog input, and then removing the bias (should be around 512 ticks) from the sampled signal.

Electronic – arduino – Why is microphone + opAmp + Arduino circuit not working

Personally I'd have the input more like this:

enter image description here

That will provide 100x amplification. If you want less then increase R2 or decrease R5. If you want more then decrease R2 or increase R5.

It may not be a 100% perfect circuit, but it's one I have used successfully.

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Arduino + Microphone how to grab values

Electronic – arduino – Why is microphone + opAmp + Arduino circuit not working

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