This Arduino program integrates with PIR (Passive Infrared) motion sensors...

September 3, 2025 at 02:12 PM

#include <Servo.h>

// === PIR sensor pins ===
#define PIR_NORTH 2
#define PIR_EAST  3
#define PIR_SOUTH 4
#define PIR_WEST  5

// === Servo objects ===
Servo camA;  
Servo camB;  

// === Servo pins ===
#define CAM_A_SERVO 9
#define CAM_B_SERVO 10

// === Camera Angles (adjust to setup) ===
int angleNorth = 0;    
int angleEast  = 90;   
int angleSouth = 180;  
int angleWest  = 270;  // for 360° servo mapping, or remap to standard servo 0–180°

// === Default angle ===
int defaultAngleA = 90;
int defaultAngleB = 90;

// === Timing ===
unsigned long lastDetection = 0;
unsigned long detectionTimeout = 5000; // 5 seconds

void setup() {
  // PIR setup
  pinMode(PIR_NORTH, INPUT);
  pinMode(PIR_EAST, INPUT);
  pinMode(PIR_SOUTH, INPUT);
  pinMode(PIR_WEST, INPUT);

  // Servo setup
  camA.attach(CAM_A_SERVO);
  camB.attach(CAM_B_SERVO);

  // Move cameras to default position
  camA.write(defaultAngleA);
  camB.write(defaultAngleB);

  Serial.begin(9600);
}

void loop() {
  bool motionNorth = digitalRead(PIR_NORTH);
  bool motionEast  = digitalRead(PIR_EAST);
  bool motionSouth = digitalRead(PIR_SOUTH);
  bool motionWest  = digitalRead(PIR_WEST);

  if (motionNorth) {
    Serial.println("Motion North!");
    camA.write(angleNorth);
    lastDetection = millis();
  }
  else if (motionEast) {
    Serial.println("Motion East!");
    camB.write(angleEast);
    lastDetection = millis();
  }
  else if (motionSouth) {
    Serial.println("Motion South!");
    camA.write(angleSouth);
    lastDetection = millis();
  }
  else if (motionWest) {
    Serial.println("Motion West!");
    camB.write(angleWest);
    lastDetection = millis();
  }

  // Return cameras to default if no detection
  if (millis() - lastDetection > detectionTimeout) {
    camA.write(defaultAngleA);
    camB.write(defaultAngleB);
  }
}

This Arduino program integrates with PIR (Passive Infrared) motion sensors and two servo motors to monitor and respond to motion detection in four directions: North, East, South, and West. Here's what the code does:

Hardware Setup:
- PIR Sensors: Four PIR sensors are connected to digital pins 2, 3, 4, and 5 corresponding to North, East, South, and West directions.
- Servos: Two servo motors (camA and camB) are controlled via pins 9 and 10. These servos are responsible for moving towards detected motion.
Predefined Angles:
- The servos are set to move to specific angles depending on the motion direction (angleNorth, angleEast, angleSouth, angleWest).
- Default positions for the servos are specified (defaultAngleA and defaultAngleB, both set to 90 degrees).
Motion Detection and Servo Response:
- In the loop function, the program continuously checks for motion signals from the PIR sensors.
- When motion is detected in a specific direction:
  - It prints a message to the Serial monitor about the motion direction.
  - The corresponding servo (camA or camB) is moved to the predefined angle for that direction.
  - The timestamp of detection is updated using millis().
Timeout for Reset:
- If no motion is detected for a specified timeout (detectionTimeout, set to 5 seconds), the servos return to their default positions.
Behavior:
- Upon motion detection, a servo will point towards the respective direction.
- If no further motion occurs after the timeout duration, the cameras will reset to face their default positions.

Summary:

The code is a motion-tracking system using PIR sensors and servos. It detects motion from four directions, rotates servos to point towards the detected direction, and resets to a default position if no motion is detected for 5 seconds. It can be used for applications such as security cameras or motion-tracking systems.

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