ARDUINO One Transistor Sound Detector





Introduction: ARDUINO One Transistor Sound Detector

This easy to build circuit will let you detect sound with your ARDUINO, You can buy a pre made sound detection sensor module but they don't work worth a sh!t from my experience.
The picture above shows you the simple circuit design, just build that and it will work better than most of the pre maid modules you can buy.

2 - 10kΩ resistors.
1 - 100kΩ resistor.
1 - 1mΩ resistor.
2 - 0.1 µf capacitors (Mylar is the best but ceramic will work if that's all you have).
1 - microphone.
1 - MPS2222A Transistor (a 2n2222 or 2n2222A should work too).
1 - diode a 1N4001 or similar will work.
1 - ARDUINO micro controller of any type should work.
For the output (Testing side of the circuit you will need):
1 - RED led.
1 - 220Ω resistor.

If you need to order any of these parts or need some new stuff to play with check out this link to the site I buy all my ARDUINO supplies.... This is the cheapest place I have found to date!!!!

Step 1: Testing the Circuit

//Now that you have built the circuit lets see it in action!
//copy and past this entire page into your arduino ide, don't worry Its formatted to work with no problems...
int led=9;
void setup() {
void loop() {
int val=analogRead(A0); //read the sound level
Serial.println(val); //print sound level to serial monitor
if (val>15) //change this value (15) to tell the program when to trigger the effect!!
digitalWrite(led,HIGH); //put what you want the program to do if sound is detected here!!!
delay(10); //for stability
//The code is pretty straight forward so I'm not going to explain it.....
//when you make a noise the led should light up for one second, if it don't work check to make sure the circuit is constructed properly
// If you are having problems with it please message me and ill help you out if I can....
// 73's and good luck with the project............................



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    it's video exist or not!

    i have made this circuit but it is not working !

    if i see its video that how it works i can made it to work.

    How would I modify this circuit to detect a louder or quieter sounds? ie Let's say I wanted it to be sensitive to low decibel levels or able to distinguish sound on the high side of things?