Programming Examples

Arduino program to interface a PIR (Passive Infrared) sensor


 PIR (Passive Infrared) sensor

Arduino to interface a PIR (Passive Infrared) sensor . A PIR sensor detects motion by measuring changes in infrared levels emitted by surrounding objects.

Components Needed:

  • Arduino board (e.g., Uno)
  • PIR sensor module
  • Breadboard and jumper wires

Circuit Connection:

  • Connect the VCC pin of the PIR sensor to the 5V pin of the Arduino.
  • Connect the GND pin of the PIR sensor to the GND pin of the Arduino.
  • Connect the OUT pin of the PIR sensor to digital pin 2 of the Arduino.
Solution

void setup() {
  Serial.begin(9600);
  pinMode(2, INPUT);
  pinMode(13, OUTPUT);
}
void loop() {
  int sensorValue = digitalRead(2);
  Serial.println(sensorValue);
  if (sensorValue == HIGH) {
    digitalWrite(13, HIGH);
  } else {
    digitalWrite(13, LOW);
  }
  delay(100);
}
▶ RUN

Output/ Explanation:

pinMode(pirSensorPin, INPUT);: Configures the pin connected to the PIR sensor as an input.

digitalRead(pirSensorPin);: Reads the value from the PIR sensor. It returns HIGH if motion is detected and LOW if no motion is detected.

Serial.println(sensorValue);: Prints the sensor value to the Serial Monitor.

digitalWrite(ledPin, HIGH);: Turns on the built-in LED when motion is detected.

digitalWrite(ledPin, LOW);: Turns off the built-in LED when no motion is detected.

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