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Sound Sensor

Components Needed

  • 1x ESP32
  • 1x USB Programming Cable
  • 1x Double Width Breadboard
  • 1x Sound Sensor Module
  • 3x Male-to-Male Jumper Wires

Connections

Using the breadboard, connect the Sound Sensor Module to the ESP32 as follows:

  • + (VCC) → ESP32 3V3
  • G (GND) → ESP32 GND
  • A0 (Analog Output) → ESP32 D32

Code

Upload the following code onto the ESP32:

int sensorPin = 32;   // ADC1 pin for sound sensor
int ledPin = 2;       // LED pin
int sensorValue = 0;  // Variable to store sensor reading
int threshold = 2000; // Adjust this based on your sensor's noise level

void setup() {
  Serial.begin(115200);
  pinMode(ledPin, OUTPUT);
}
void loop() {
  sensorValue = analogRead(sensorPin);
  Serial.println(sensorValue);

  if (sensorValue > threshold) {
    digitalWrite(ledPin, HIGH); // Turn LED on if sound is loud
  } else {
    digitalWrite(ledPin, LOW);  // Turn LED off if quiet
  }

  delay(10); // Small delay for stability
}

Explanation

The Sound Sensor is an analog/digital sensor that uses a condenser microphone to detect changes in environmental noise. It is commonly used to identify sounds above a certain level. The module includes a potentiometer to adjust the noise detection threshold.

It provides two outputs:

  1. A0 (Analog Output): This gives values representing the detected noise level. These values depend on the supplied voltage and potentiometer position, making it difficult to reconstruct actual audio.
  2. DO (Digital Output): This provides a HIGH signal when the sound level exceeds the threshold set by the potentiometer.

In the following Arduino sketch, we’ll measure noise levels using the analog output (A0) of the Sound Sensor.

Before testing, you must calibrate the module using the potentiometer:

  1. Upload the code and open the Serial Monitor.
  2. Observe the analog values printed on the screen.
  3. If the value is far from 2000, adjust the potentiometer:
  4. Turn clockwise if the value is too low.
  5. Turn counter-clockwise if the value is too high.
  6. Keep adjusting until the analog value stabilizes just below 2000 in a quiet environment. You may need to turn the potentiometer up to 20 times. To make precise adjustments, we recommend removing the module, turning the potentiometer three times, reinserting it, and then checking the reading.
  7. Once set, speak near the microphone and check if the onboard led lights up when the noise level increases.

Results

After calibration, the LED on Pin 2 will turn on when the sound level exceeds 2000. The Serial Monitor will display the real-time noise intensity values, allowing you to fine-tune the detection threshold.

Try for Yourself

  1. Adjust the potentiometer on the sound sensor module to set a different sound threshold.
  2. Modify the code to perform specific actions, such as triggering an alarm or sending notifications, based
  3. n the sound intensity.