PIR Motion Sensor Module MH-SR602

Features:

• Wide operating voltage range: 3.3V to 15V
• Low static power consumption: < 20µA
• Output delay time: 2 seconds
• 100° detection angle
• Detection range: 3.5 to 5 meters
• High reliability with repeat trigger mode
• Can be used independently or with microcontrollers like Arduino, ESP8266, Raspberry Pi, etc.
• Optional light-sensitive feature: works only at night if a photosensitive component is installed
• Simple analog circuit compatibility

Principle of Operation:

The PIR sensor detects changes in infrared radiation caused by motion. When a warm body (like a human) moves within its field of view, the sensor notices the temperature shift and triggers an output. The sensor continuously resets the trigger duration if motion is detected repeatedly, allowing sustained activation of devices like lights or alarms.

Pinout:

Applications:

• Intruder alarm systems
• Automatic lighting
• Security systems
• Hand dryers
• Automatic doors

Circuit Diagram:

Library:

No library is required to use this module with Arduino.

Sample Arduino Code:

int led = 13;           // LED pin
int sensor = 2;         // Sensor pin
int state = LOW;        // Motion state
int val = 0;            // Sensor value

void setup() {
  pinMode(led, OUTPUT);     
  pinMode(sensor, INPUT);    
  Serial.begin(9600);       
}

void loop() {
  val = digitalRead(sensor);  
  if (val == HIGH) {         
    digitalWrite(led, HIGH); 
    delay(500);
    if (state == LOW) {
      Serial.println("Motion detected!");
      state = HIGH;
    }
  } else {
    digitalWrite(led, LOW);
    delay(500);
    if (state == HIGH) {
      Serial.println("Motion stopped!");
      state = LOW;
    }
  }
}

Technical Specifications:

Comparisons:

The SR-602 is ideal for battery-powered applications due to its extremely low power consumption (20µA). Compared to alternatives:

• AM312: Works at 2.7V with an 8-second delay, but has higher current usage (~0.1mA)
• HC-SR505: Works from 5V to 20V, but not ideal for 3.3V microcontrollers
• SR-602: Best suited for 3.3V logic devices (e.g., ESP8266), includes a photosensitive feature, and consumes less power