Flame detector project Arduino

1#include <LiquidCrystal.h>
2#include <Servo.h>
3
4// --- Pin Definitions ---
5LiquidCrystal lcd(3, 4, 5, 6, 7, 8);
6Servo scannerServo;
7
8const int servoPin = 9;
9const int greenLedPin = 22;
10const int redLedPin = 50;
11const int buzzerPin = 23;
12const int flameSensorPin = 52; 
13
14int servoPos = 0;       // Current servo position
15int servoDirection = 1; // 1 means moving forward, -1 means moving backward
16
17void setup() {
18  lcd.begin(16, 2);
19  lcd.print("System Booting..");
20  
21  pinMode(greenLedPin, OUTPUT);
22  pinMode(redLedPin, OUTPUT);
23  pinMode(buzzerPin, OUTPUT);
24  pinMode(flameSensorPin, INPUT);
25  
26  scannerServo.attach(servoPin);
27  scannerServo.write(servoPos); // Start at 0 degrees
28  
29  delay(1000); 
30  lcd.clear();
31}
32
33void loop() {
34  // Read the flame sensor
35  int flameDetected = digitalRead(flameSensorPin);
36  
37  // ---> THE FIX IS HERE <---
38  // We changed this to LOW. Now, if the sensor outputs LOW (0V), the system sweeps.
39  // If it detects fire and outputs HIGH (5V), it jumps to the alarm mode.
40  if (flameDetected == LOW) { 
41    
42    // --- NO FLAME: SWEEP NORMALLY ---
43    digitalWrite(redLedPin, LOW);    // Red OFF
44    digitalWrite(greenLedPin, HIGH); // Green ON
45    digitalWrite(buzzerPin, LOW);    // Buzzer OFF
46    
47    lcd.setCursor(0, 0);
48    lcd.print("Fire Scanner ON ");
49    lcd.setCursor(0, 1);
50    lcd.print("Area Secure...  ");
51
52    // Move servo to the current position
53    scannerServo.write(servoPos);
54    
55    // Step the position forward or backward
56    servoPos += servoDirection;
57    
58    // If we hit the boundaries (0 or 80), reverse the direction
59    if (servoPos >= 80) {
60      servoDirection = -1; // Start moving backward
61    } else if (servoPos <= 0) {
62      servoDirection = 1;  // Start moving forward
63    }
64    
65    delay(20); // Speed of the sweep
66    
67  } 
68  else { 
69    // --- FLAME DETECTED: LOCK TARGET & ALARM ---
70    // Because we DO NOT change "servoPos" here, the motor freezes in its exact spot.
71    // When the fire is removed, the code goes back to the "if" block above 
72    // and resumes moving from this exact spot!
73    
74    digitalWrite(redLedPin, HIGH);   // Red ON
75    digitalWrite(greenLedPin, LOW);  // Green OFF
76    digitalWrite(buzzerPin, HIGH);   // Buzzer ON
77    
78    lcd.setCursor(0, 0);
79    lcd.print("FIRE AT ");
80    lcd.print(servoPos);
81    lcd.print(" DEG!   "); 
82    
83    lcd.setCursor(0, 1);
84    lcd.print("FIRE DETECTED!! ");
85    
86    delay(100); 
87  }
88}