KY-037 Sound Sensor — High Sensitivity Microphone Detection for Arduino / ESP32 (WLED Trigger)

# ESPHome YAML — KY-037 sound sensor (ESP32) -> trigger WLED via HTTP
esphome:
  name: ky037_sound_node
  platform: ESP32
  board: esp32dev

wifi:
  ssid: "YOUR_SSID"
  password: "YOUR_PASSWORD"

logger:
api:
ota:

# ADC sensor (AO) — raw analog level
sensor:
  - platform: adc
    pin: 35               # AO connected to ADC pin (change as required)
    name: "Sound Level (Raw)"
    id: sound_raw
    update_interval: 1s
    accuracy_decimals: 2
    unit_of_measurement: "V"
    filters:
      - sliding_window_moving_average:
          window_size: 5
          send_every: 1

# Digital threshold (DO)
binary_sensor:
  - platform: gpio
    pin:
      number: 13          # DO pin wired here
      mode: INPUT_PULLUP  # adjust depending on module wiring
      inverted: false
    name: "Sound Threshold (DO)"
    id: sound_do
    on_press:
      then:
        - logger.log: "Sound DO triggered — toggling WLED"
        # Example: send HTTP request to WLED to toggle (replace WLED_IP)
        - http_request.post:
            url: "http://WLED_IP/json/state"
            headers:
              Content-Type: "application/json"
            body: '{"on":true}'
            timeout: 5000
        - delay: 500ms
        - http_request.post:
            url: "http://WLED_IP/json/state"
            headers:
              Content-Type: "application/json"
            body: '{"on":false}'
            timeout: 5000

# Optional automation: act when analog level above a threshold
script:
  - id: check_sound_level
    then:
      - lambda: |-
          if (id(sound_raw).state > 1.0) { // example threshold in volts
            ESP_LOGD("sound", "Analog threshold crossed: %f", id(sound_raw).state);
            // add actions here (e.g., toggle local relay or call WLED)
          }

# Optional: expose sensor to Home Assistant via API (api: above) for automations

Replace WLED_IP with your WLED device IP. The example sends a quick ON then OFF; modify body JSON to set colors/effects. Using WLED JSON endpoint requires WLED to have JSON API enabled (default).

// Arduino (ESP32) — KY-037 sound sensor example
// AO -> ADC (e.g., 35), DO -> digital (e.g., 13), RELAY -> digital (e.g., 25)
// For WLED HTTP calls, uncomment WiFi / HTTP sections and add WLED IP

#include <WiFi.h>            // only needed for HTTP to WLED
#include <HTTPClient.h>     // only needed for HTTP to WLED

const int pinAO = 35;      // analog out
const int pinDO = 13;      // digital out (threshold)
const int pinRelay = 25;   // relay or LED to indicate trigger

// ---- Optional WLED settings (for HTTP trigger) ----
// const char* ssid = "YOUR_SSID";
// const char* password = "YOUR_PASS";
// const char* wledIP = "http://WLED_IP/json/state";

void setup() {
  Serial.begin(115200);
  pinMode(pinDO, INPUT);
  pinMode(pinRelay, OUTPUT);
  digitalWrite(pinRelay, LOW);

  // Optional: WiFi.begin(ssid, password) if using WLED HTTP
}

void loop() {
  int analogRaw = analogRead(pinAO); // 0..4095 on many ESP32 cores
  float voltage = analogRaw * (3.3 / 4095.0);
  int doState = digitalRead(pinDO);

  Serial.printf("AO raw: %d  V: %.2f  DO: %d\n", analogRaw, voltage, doState);

  // If digital output goes HIGH (or LOW depending on module), toggle relay
  if (doState == HIGH) {
    digitalWrite(pinRelay, HIGH); // activate relay / indicator
    delay(200);                    // keep it on briefly
    digitalWrite(pinRelay, LOW);
  }

  // Optional: call WLED via HTTP to toggle or set effect
  /*
  if (doState == HIGH) {
    if (WiFi.status() == WL_CONNECTED) {
      HTTPClient http;
      http.begin(String(wledIP)); // e.g. "http://192.168.1.50/json/state"
      http.addHeader("Content-Type", "application/json");
      int httpCode = http.POST("{\"on\":true}");
      Serial.printf("WLED HTTP POST returned %d\n", httpCode);
      http.end();
    }
  }
  */

  delay(200); // sample rate
}

Notes: adjust ADC pin and digital pin to match your board. The DO pin logic depends on the module sensitivity potentiometer and module version (test on bench first). If using WLED HTTP, enable Wi-Fi and set the WLED device IP.