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KY-038 High Sensitivity Small Microphone Sound Sensor Module 4Pin

SKU: FA3019-1
Module Model

KY-038
Sensor Type

Electret condenser microphone
Operating Voltage

3.3V – 5V DC
Output Type

Analog (AO) + Digital (DO)
Comparator IC

LM393
Sensitivity Adjustment

Onboard potentiometer
Indication

LED indicator for digital output
Pin Count

4 pins (VCC, GND, DO, AO)

The KY-038 High Sensitivity Small Microphone Sound Sensor Module is a compact, versatile audio detection board designed for Arduino, ESP32, STM32, and other microcontroller projects. It uses a high-sensitivity electret microphone to detect ambient sound levels and provides both analog and digital outputs, making it suitable for a wide range of applications including sound-activated switches, clap detectors, noise monitoring, and voice-triggered projects.

At the heart of the module is a high-sensitivity electret condenser microphone that converts sound waves into electrical signals. The signal is then amplified by an LM393 comparator (on the digital side) and passed through to the outputs. The module provides two independent outputs:

  • Analog Output (AO) — A continuous voltage that varies proportionally to the ambient sound level. This output connects to your microcontroller’s ADC pin, allowing you to measure sound intensity in real time.

  • Digital Output (DO) — A HIGH/LOW signal that switches when the sound level exceeds a user-adjustable threshold. This output is ideal for simple sound-triggered switching applications.

The digital output threshold is set using the onboard potentiometer. Turn the potentiometer clockwise to increase sensitivity (trigger on quieter sounds) or counter-clockwise to decrease sensitivity (trigger only on loud sounds). An LED indicator lights up when the digital output is triggered, providing visual feedback during setup and operation.

The module operates from a 3.3V to 5V DC supply, making it compatible with Arduino, ESP32, STM32, Raspberry Pi, and other microcontrollers. The 4-pin interface (VCC, GND, DO, AO) provides easy connection to your project. The compact form factor with mounting holes allows integration into custom enclosures, sound-activated devices, and portable electronics.

The KY-038 is widely used in sound-activated switches, clap detectors, noise level monitoring, voice-activated projects, security systems, interactive art installations, and educational STEM projects. It is also popular in DIY electronics and maker projects where sound detection is required.

Important Note: The KY-038 detects sound intensity, not specific frequencies or speech content. For voice recognition or frequency-specific detection, a more advanced audio processing module is required. The module is not waterproof and should be kept dry. The microphone’s sensitivity can be affected by ambient noise levels, so calibrate the potentiometer for your specific environment.

Whether you are building a clap-activated light, a noise monitor, or a sound-triggered robot, the KY-038 High Sensitivity Sound Sensor Module provides a reliable, affordable solution. It is suitable for individual makers, students, and businesses purchasing in bulk for product development or educational programs.

Features

  • High-sensitivity electret microphone — Detects ambient sound levels

  • Dual outputs — Analog (AO) for sound intensity, Digital (DO) for threshold triggering

  • Adjustable sensitivity — Onboard potentiometer for digital output threshold

  • LED indicator — Visual feedback when digital output is triggered

  • Wide voltage range — 3.3V to 5V DC, compatible with Arduino, ESP32, STM32, Raspberry Pi

  • 4-pin interface — VCC, GND, DO, AO for simple connection

  • Compact form factor — With mounting holes for easy integration

  • Wide application range — Sound-activated switches, clap detectors, noise monitoring

  • Simple interface — Direct connection to ADC and digital input pins

  • Cost-effective — Affordable solution for sound detection in volume production

Technical Specifications 

# Parameter Specification
1 Module Model KY-038
2 Sensor Type Electret condenser microphone
3 Operating Voltage 3.3V – 5V DC
4 Output Type Analog (AO) + Digital (DO)
5 Comparator IC LM393
6 Sensitivity Adjustment Onboard potentiometer
7 Indication LED indicator for digital output
8 Pin Count 4 pins (VCC, GND, DO, AO)

Usage

Getting Started

  1. Connect power — Supply 3.3V or 5V DC to the VCC pin and GND to ground.

  2. Connect the outputs — Connect the DO pin to a digital input pin (e.g., D2 on Arduino) and the AO pin to an analog input pin (e.g., A0).

  3. Adjust sensitivity — Use the onboard potentiometer to set the digital output threshold. Turn clockwise to increase sensitivity.

  4. Upload a test sketch — Read the analog value from AO and the digital state from DO. Observe the values change as sound levels vary.

  5. Implement control logic — Use the digital output for simple sound-triggered switching, or the analog output for sound intensity measurement.

Pin Connections

Module Pin Function
VCC Power (3.3V–5V)
GND Ground
DO Digital output (LOW when sound exceeds threshold)
AO Analog output (voltage proportional to sound level)

Output Logic

Condition Digital Output (DO) Analog Output (AO)
Quiet HIGH Low voltage
Sound detected LOW Higher voltage

Example Arduino Code

cpp
#define DO_PIN 2
#define AO_PIN A0

void setup() {
  Serial.begin(9600);
  pinMode(DO_PIN, INPUT);
}

void loop() {
  int digitalValue = digitalRead(DO_PIN);
  int analogValue = analogRead(AO_PIN);

  Serial.print("Digital: "); Serial.print(digitalValue);
  Serial.print(" Analog: "); Serial.println(analogValue);

  if (digitalValue == LOW) {
    Serial.println("Sound Detected!");
  }

  delay(100);
}

Typical Applications

  • Sound-activated switches — Turn lights or devices on with a clap or loud sound

  • Clap detectors — Trigger actions with hand claps

  • Noise level monitoring — Measure ambient sound intensity

  • Voice-activated projects — Basic sound-triggered control

  • Security systems — Detect unusual sounds or disturbances

  • Interactive art installations — Sound-reactive visual effects

  • Educational STEM projects — Teaching sound sensing and analog/digital conversion

Notes for Business Buyers

  • Dual outputs — Analog for measurement, digital for switching.

  • Adjustable sensitivity — Potentiometer allows adaptation to different environments.

  • Simple interface — Direct connection to ADC and digital input pins.

  • Suitable for bulk purchasing — Ideal for sound-activated product manufacturers, educational institutions, and product development.

Q: What is the KY-038 Sound Sensor Module used for?

It is a sound detection module for sound-activated switches, clap detectors, noise monitoring, voice-triggered projects, and security systems.

Q: What is the difference between the analog and digital outputs?

The analog output (AO) provides a continuous voltage proportional to sound intensity, while the digital output (DO) switches HIGH/LOW when sound exceeds a user-adjustable threshold.

Q: What voltage does the module require?

It operates from 3.3V to 5V DC, making it compatible with Arduino, ESP32, STM32, and Raspberry Pi.

Q: How do I adjust the sensitivity?

Use the onboard potentiometer. Turn clockwise to increase sensitivity (trigger on quieter sounds) or counter-clockwise to decrease sensitivity.

Q: What is the comparator IC used on the module?

The module uses an LM393 comparator for the digital output.

Q: Does the module detect specific frequencies or speech?

No. The KY-038 detects sound intensity, not specific frequencies or speech content. For voice recognition, a more advanced module is required.

Q: How do I connect the module to an Arduino?

Connect VCC to 5V, GND to GND, DO to D2, and AO to A0. Use digitalRead() for DO and analogRead() for AO.

Q: What is the output logic of the digital pin?

The digital output is LOW when sound exceeds the threshold and HIGH when quiet. Verify with your specific module.

Q: Is the module waterproof?

No. The module is not waterproof and should be kept dry.

Q: Can I purchase in bulk for a product development project?

Yes. This module is suitable for both individual users and business purchasing, including sound-activated product manufacturers, educational institutions, and product development.

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