Sound Sensor

Hello guys

I need some help with my sound sensor, I use this circuit…

so, I made this circuit in my protoboard, but arduino crash when a wire the ground in arduino ground pin…and none happens when I clap in the mic…there’s no response…

look my schema in protoboard…

any help?


Well - you don’t have your transistor hooked up right, for one thing; on a breadboard, the “vertical” columns of connections are all hooked together; you essentially have a short going on (notice how the software you are using puts a “green” line over the holes? that’s to indicate that these are all “connected together”). The rest of your circuit looks like it may be OK (I didn’t check too close) - so if you flip your transistor from running vertically on one column, and run it horizontally over three columns, then adjust the rest of the wiring, it may work better…

ok, I see....

I have hook middle leg of transistor in another columns?

I have hook middle leg of transistor in another columns?

Every column on the board is hooked together (the top and the bottom are separate sections, though - the valley in between); so the three pins of the transistor (Emitter/Base/Collector) need to each be on a different column - so the transistor legs should be across 3 column, one leg in each column. You might have to spread the legs a bit, but it will fit (that sounds dirty ;D).

You should also leave out the decoupling capacitor C2 when connecting to the ADC

That is only if you are running the amplifier off 5v. If you are running it off more then you need the capacitor and a reverse biased diode to protect the input from negative voltages.

Thanks for help

I use 5v from arduino

Guys, look pics of the my protoboard

I continue receive from arduino values up to 930 and when I clap in mic there no response…

I’m still crazyyyyy… :stuck_out_tongue:

does something is wrong in my proto?


A couple of things I can see right off hand which may or may not be a part of your troubles:

  1. Using bare copper wire to make the connections - this shouldn't be done. Not a good practice.

  2. Inserting a wire or component into a hole that already has a wire or component in it - this is wrong. You should only have one wire or component lead in a single hole. Putting two component leads or wires into the same hole might not complete the conduction path between both components, and it can also spread the spring clips inside the holes so that they don't make good contact with the parts; now or in the future. DON'T DO IT.

As I said, though - I can't say if this is the issue with what you wired, I am just noticing you have bad practices going on with that board that could lead to issues (spurious connections etc) both now and in the future.


Oh - I do see a big problem with your layout - you have both leads of the microphone on the same column! YOU CAN'T DO THIS. Just like the transistor - one lead per column!


humm, I see…I’m new, sorry :-[

thanks for you help…I will try every you say :smiley:

thx man

hello guys...

I get some sound variation when I whistle in mic...... :smiley: ;D
but still get values up to 200 a 290.......but when I whistle or blow in mic I get values up to 800 a 900......and led on... :wink: :smiley:

but some times when have no sound, I get values variation above 300
see my code

#define INPUT_PIN 5
#define OUTPUT_PIN 3
#define NOISE_GATE 300
#define DELAY 100

unsigned char state;
unsigned short rd;
int ledPin = 13;

void setup(){
pinMode(ledPin, OUTPUT); 

void loop() {
  rd = analogRead(INPUT_PIN);
  if (rd > NOISE_GATE) {
    state = ~state;
    //analogWrite(OUTPUT_PIN, state);
  digitalWrite(ledPin, HIGH);   // set the LED on
  delay(1000);                  // wait for a second
  digitalWrite(ledPin, LOW);    // set the LED off

thx guys