How to Use ky_027: Examples, Pinouts, and Specs

The KY-027 is a sound sensor module designed to detect sound levels and convert them into an analog voltage output. It is equipped with a microphone and supporting circuitry to amplify and process sound signals. This module is widely used in projects that require sound detection, such as sound-activated alarms, voice-controlled systems, and environmental monitoring devices.

• Sound-activated alarms
• Voice-controlled devices
• Environmental noise monitoring
• Audio level detection in smart systems

The KY-027 sound sensor module has the following key specifications:

The KY-027 module has three pins, as described below:

1. Power the Module: Connect the VCC pin to a 3.3V or 5V power source and the GND pin to the ground.
2. Connect the Output:
   • For analog sound level detection, connect the OUT pin to an analog input pin of your microcontroller.
   • For digital sound detection, adjust the onboard potentiometer to set the desired sound threshold. The OUT pin will output HIGH when the sound level exceeds the threshold.
3. Read the Output:
   • Use an analog-to-digital converter (ADC) to read the analog output.
   • For digital output, monitor the HIGH/LOW state of the OUT pin.

• Power Supply: Ensure a stable power supply to avoid noise in the output signal.
• Potentiometer Adjustment: Use the onboard potentiometer to fine-tune the sensitivity of the digital output.
• Placement: Place the module in an area free from excessive vibrations or electrical noise for accurate sound detection.
• Analog vs. Digital Output: Use the analog output for precise sound level measurements and the digital output for simple threshold-based detection.

Below is an example of how to connect and use the KY-027 with an Arduino UNO to read both analog and digital outputs.

• Connect VCC to the 5V pin on the Arduino.
• Connect GND to the GND pin on the Arduino.
• Connect OUT to both an analog input pin (e.g., A0) and a digital input pin (e.g., D2).

// Define pin connections
const int analogPin = A0;  // Analog pin connected to KY-027 OUT
const int digitalPin = 2;  // Digital pin connected to KY-027 OUT

void setup() {
  Serial.begin(9600);  // Initialize serial communication
  pinMode(digitalPin, INPUT);  // Set digital pin as input
}

void loop() {
  // Read analog output from KY-027
  int soundLevel = analogRead(analogPin);
  Serial.print("Analog Sound Level: ");
  Serial.println(soundLevel);

  // Read digital output from KY-027
  int soundDetected = digitalRead(digitalPin);
  if (soundDetected == HIGH) {
    Serial.println("Sound detected (Digital Output HIGH)");
  } else {
    Serial.println("No sound detected (Digital Output LOW)");
  }

  delay(500);  // Wait for 500ms before the next reading
}

1. No Output from the Module:

   • Ensure the module is powered correctly (check VCC and GND connections).
   • Verify that the microphone is not damaged.
   • Check the potentiometer setting; it may need adjustment.

2. Inconsistent Analog Readings:

   • Ensure the power supply is stable and free from noise.
   • Avoid placing the module near sources of electrical interference.

3. Digital Output Always HIGH or LOW:

   • Adjust the potentiometer to set an appropriate sound threshold.
   • Verify that the sound level exceeds the set threshold for HIGH output.

Q: Can the KY-027 detect specific frequencies of sound?
A: No, the KY-027 is designed to detect general sound levels and does not differentiate between specific frequencies.

Q: How do I increase the sensitivity of the module?
A: Adjust the onboard potentiometer to increase the sensitivity of the digital output. For analog output, ensure the microphone is positioned closer to the sound source.

Q: Can I use the KY-027 with a 3.3V microcontroller?
A: Yes, the KY-027 operates at both 3.3V and 5V, making it compatible with most microcontrollers.

Q: What is the range of sound levels the KY-027 can detect?
A: The KY-027 can detect a wide range of sound levels, but its sensitivity depends on the microphone and the potentiometer setting. It is suitable for general sound detection rather than precise measurements.