#include #include #include // WiFi credentials const char* ssid = "Jay"; const char* password = "imnoone@123"; // Pin configuration #define DHTPIN 4 #define DHTTYPE DHT11 #define MQPIN 34 #define FLAMEPIN 17 #define RELAYPIN 26 #define BUZZERPIN 15 #define LEDGREEN 14 #define LEDRED 12 // Logic configuration const bool RELAY_ACTIVE_LOW = true; const bool BUZZER_ACTIVE_HIGH = true; // Thresholds const int MQ_THRESHOLD = 350; const float TEMP_THRESHOLD = 60.0; const unsigned long SAMPLE_INTERVAL_MS = 1500; // Global variables float latestTemp = 0, latestHum = 0; int latestMQRaw = 0, latestFlame = 1; unsigned long lastSampleMillis = 0; bool manualOverride = false; DHT dht(DHTPIN, DHTTYPE); WebServer server(80); // ---------- Forward Declarations (Fixes your error) ---------- void setRelay(bool on); void setBuzzer(bool on); // ------------------------------------------------------------ // ---------- Function Definitions ---------- void setRelay(bool on) { digitalWrite(RELAYPIN, RELAY_ACTIVE_LOW ? (on ? LOW : HIGH) : (on ? HIGH : LOW)); } void setBuzzer(bool on) { digitalWrite(BUZZERPIN, BUZZER_ACTIVE_HIGH ? (on ? HIGH : LOW) : (on ? LOW : HIGH)); } void handleRoot() { String page = R"rawliteral( Industrial Safety Dashboard

⚙️ Industrial Safety Dashboard

🌡 Temperature (°C)
--
💧 Humidity (%)
--
💨 Gas (MQ-2)
--
🔥 Flame
--
🛡 System Status
--
)rawliteral"; server.send(200, "text/html", page); } void handleData() { bool gasAlarm = (latestMQRaw > MQ_THRESHOLD); bool tempAlarm = (latestTemp > TEMP_THRESHOLD); bool flameAlarm = (latestFlame == 0); bool alarm = gasAlarm || tempAlarm || flameAlarm; String json = "{"; json += "\"temperature\":" + String(latestTemp, 1) + ","; json += "\"humidity\":" + String(latestHum, 1) + ","; json += "\"mqRaw\":" + String(latestMQRaw) + ","; json += "\"flame\":" + String(latestFlame) + ","; json += "\"alarm\":" + String(alarm ? "true" : "false"); json += "}"; server.send(200, "application/json", json); } void handleFanToggle() { manualOverride = true; int state = digitalRead(RELAYPIN); bool isOn = (RELAY_ACTIVE_LOW ? (state == LOW) : (state == HIGH)); setRelay(!isOn); server.send(200, "text/plain", "Fan toggled"); } void handleFanAuto() { manualOverride = false; server.send(200, "text/plain", "Auto mode enabled"); } void sampleSensors() { float t = dht.readTemperature(); float h = dht.readHumidity(); if (isnan(t) || isnan(h)) { delay(100); t = dht.readTemperature(); h = dht.readHumidity(); } int mqRaw = analogRead(MQPIN); int flame = digitalRead(FLAMEPIN); latestTemp = t; latestHum = h; latestMQRaw = mqRaw; latestFlame = flame; Serial.print("Temp: "); Serial.print(t); Serial.print(" °C | Hum: "); Serial.print(h); Serial.print(" % | MQ: "); Serial.print(mqRaw); Serial.print(" | Flame: "); Serial.print(flame == 1 ? "SAFE" : "DETECTED"); Serial.print(" | Fan: "); Serial.println((digitalRead(RELAYPIN) == (RELAY_ACTIVE_LOW ? LOW : HIGH)) ? "ON" : "OFF"); if (!manualOverride) { bool gasAlarm = (mqRaw > MQ_THRESHOLD); bool tempAlarm = (t > TEMP_THRESHOLD); bool flameAlarm = (flame == 0); bool alarm = gasAlarm || tempAlarm || flameAlarm; setRelay(alarm); setBuzzer(alarm); digitalWrite(LEDRED, alarm ? HIGH : LOW); digitalWrite(LEDGREEN, alarm ? LOW : HIGH); } } void setup() { Serial.begin(115200); delay(300); Serial.println("\nIndustrial Safety System Booting..."); pinMode(FLAMEPIN, INPUT); pinMode(RELAYPIN, OUTPUT); pinMode(BUZZERPIN, OUTPUT); pinMode(LEDGREEN, OUTPUT); pinMode(LEDRED, OUTPUT); setRelay(false); setBuzzer(false); dht.begin(); WiFi.begin(ssid, password); Serial.print("Connecting"); while (WiFi.status() != WL_CONNECTED) { delay(300); Serial.print("."); } Serial.println("\nConnected to WiFi!"); Serial.print("IP: "); Serial.println(WiFi.localIP()); server.on("/", handleRoot); server.on("/data.json", handleData); server.on("/fan/toggle", handleFanToggle); server.on("/fan/auto", handleFanAuto); server.begin(); Serial.println("Web server started."); } void loop() { server.handleClient(); unsigned long now = millis(); if (now - lastSampleMillis >= SAMPLE_INTERVAL_MS) { lastSampleMillis = now; sampleSensors(); } }