Smart LED Control with Arduino Uno एक R4 Wi-Fi & PIR Sensor

1#define PIR_PIN 2        // PIR sensor OUT
2#define RELAY_PIN 8      // Relay control pin
3#define LED_PIN 12       // LED output pin
4
5void setup() {
6  pinMode(PIR_PIN, INPUT);
7  pinMode(RELAY_PIN, OUTPUT);
8  pinMode(LED_PIN, OUTPUT);
9
10  digitalWrite(RELAY_PIN, HIGH);  // Relay OFF initially (active LOW)
11  digitalWrite(LED_PIN, LOW);     // LED OFF initially
12
13  Serial.begin(115200);
14  Serial.println("Breadboard PIR + Relay + LED system ready.");
15}
16
17void loop() {
18  int motion = digitalRead(PIR_PIN);
19
20  if (motion == HIGH) {
21    Serial.println("Motion detected!");
22
23    digitalWrite(RELAY_PIN, LOW);   // Turn ON relay
24    digitalWrite(LED_PIN, HIGH);    // Turn ON LED
25    
26    delay(2000);                    // Keep ON for 2 seconds
27
28    digitalWrite(RELAY_PIN, HIGH);  // Turn OFF relay
29    digitalWrite(LED_PIN, LOW);     // Turn OFF LED
30
31    Serial.println("Motion ended.");
32  }
33
34  delay(100); // debounce
35}