How to Use KY-002 Vibration Sensor with ESP8266

This tutorial shows how to connect the KY-002 vibration switch module to an ESP8266 board. You’ll write code to read vibration data via Serial Monitor and light up an LED when vibration is detected.

Required Components

• NodeMCU ESP8266 V2 board
• KY-002 Vibration Switch Module
• Red LED 5mm
• 220 Ohm resistor
• MB-102 Breadboard 830 Point
• Jumper wires (Male-Male, Male-Female, Female-Female)
• Micro USB cable for code upload

Wiring Diagram

Connect the components as follows

ESP8266	KY-002
Vin (5V)	+
GND	-
D2	S

ESP8266	LED
D1	Long leg (Anode)
GND	220 Ohm resistor → Short leg (Cathode)

Arduino Code for ESP8266

// Define connection pins
const int sensorPin = D2;    // KY-002 Signal pin
const int ledPin = D1;       // LED pin

void setup() {
  Serial.begin(9600);
  pinMode(sensorPin, INPUT);
  pinMode(ledPin, OUTPUT);
  
  // Get initial sensor state
  int sensorState = digitalRead(sensorPin);
  Serial.print("Initial sensor state: ");
  Serial.println(sensorState == LOW ? "Vibration Detected" : "No Vibration");
}

void loop() {
  int sensorState = digitalRead(sensorPin);
  
  if (sensorState == LOW) {
    // Vibration detected
    digitalWrite(ledPin, HIGH);
    Serial.println("Vibration Detected!");
    delay(3000);  // LED on for 3 seconds
    digitalWrite(ledPin, LOW);
  } else {
    // No vibration
    Serial.println("No Vibration");
  }
  
  delay(500);  // Delay between readings
}

Note: This is a basic example for understanding how the sensor works. For more reliable detection, consider using interrupt-based logic or debouncing techniques.

Upload Steps

1. Open Arduino IDE
2. Set Board to NodeMCU 1.0 (ESP-12E Module) via Tools → Board
3. Select the correct Port via Tools → Port
4. Click the Upload button
5. Open Serial Monitor and set Baud Rate to 9600

Testing the Setup

After uploading the code, open the Serial Monitor

• With no vibration, you’ll see “No Vibration” printed every 0.5 seconds
• Gently tap the table or shake the board to trigger the sensor — LED will light up and the message changes to “Vibration Detected!” for 3 seconds
• Stronger shakes produce clearer LED responses

Important Notes

• ESP8266 GPIO uses 3.3V logic levels. KY-002 powered by 5V may output 5V signal which could cause reliability issues. Consider using a voltage divider or powering the sensor from 3.3V if available
• KY-002 is a mechanical switch and may produce bounce. Add debounce logic if you need precise detection timing