LM393 Sound Sensor with ESP32: Build a WiFi Noise Monitor

// LM393 Sound Sensor with ESP32
// Detects sound events and prints to Serial Monitor
// Tutorial: https://comparator.online/tutorials/lm393-esp32-sound-sensor/

const int analogPin = 34;   // AO to GPIO 34
const int digitalPin = 4;  // DO to GPIO 4
const int ledPin = 2;       // Built-in LED

// Sound detection threshold (tune to your environment)
const int SOUND_THRESHOLD = 1500;

void setup() {
  Serial.begin(115200);
  pinMode(digitalPin, INPUT);
  pinMode(ledPin, OUTPUT);
  Serial.println("ESP32 LM393 Sound Sensor Ready");
}

void loop() {
  int analogValue = analogRead(analogPin);
  int digitalValue = digitalRead(digitalPin);

  // Detect sound event (analog above threshold)
  if (analogValue > SOUND_THRESHOLD) {
    Serial.print("🔊 Sound detected! Level: ");
    Serial.println(analogValue);
    digitalWrite(ledPin, HIGH);
  } else {
    digitalWrite(ledPin, LOW);
  }

  // Print digital state
  if (digitalValue == HIGH) {
    Serial.println("⚠️  Threshold triggered (DO=HIGH)");
  }

  delay(50);
}

# LM393 Sound Sensor with ESP32 - MicroPython
from machine import Pin, ADC
import time

analog_pin = ADC(Pin(34))     # AO on GPIO 34
analog_pin.atten(ADC.ATTN_11DB)  # Full range 0-3.3V
digital_pin = Pin(4, Pin.IN)  # DO on GPIO 4
led = Pin(2, Pin.OUT)        # Built-in LED

SOUND_THRESHOLD = 1500

print("ESP32 Sound Sensor Ready")

while True:
    level = analog_pin.read()
    triggered = digital_pin.value() == 1

    if level > SOUND_THRESHOLD or triggered:
        print(f"Sound! Level={level}, Trigger={triggered}")
        led.on()
    else:
        led.off()

    time.sleep_ms(50)

# ESPHome configuration for LM393 sound sensor
esphome:
  name: esp32-sound-sensor
  platform: ESP32
  board: esp32dev

wifi:
  ssid: "YourWiFi"
  password: "YourPassword"

api:
  encryption:
    key: "your-api-key"

binary_sensor:
  - platform: gpio
    pin:
      number: GPIO4
      inverted: true
    name: "Sound Detected"
    device_class: sound

sensor:
  - platform: adc
    pin: GPIO34
    name: "Sound Level"
    update_interval: 1s
    filters:
      - sliding_window_moving_average:
          window_size: 15
          send_every: 15