🔥 Fire Detection System using Arduino

This project is a Fire Detection System built using an Arduino Uno, an MQ-2 smoke sensor, an LED, and a buzzer. It detects smoke levels and provides a local visual and audible alert, making it useful for fire safety and early-warning applications.

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🛠️ Components Used

• 🔹 Arduino Uno – Processes sensor data and controls outputs.
• 🔹 MQ-2 Smoke Sensor – Detects smoke and combustible gases.
• 🔹 LED (+ ~220–330 Ω resistor) – Visual alert when smoke is detected.
• 🔹 Buzzer – Audible alert for fire warnings.

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🔌 Wiring

Arduino Pin	Connects to
A0	MQ-2 analog out (AO) (sensor VCC → 5V, GND → GND)
D7	LED + via a ~220–330 Ω resistor (LED − → GND)
D8	Buzzer + (buzzer − → GND)

⚠️ MQ-2 sensors need their heater to warm up before readings are reliable. The sketch ignores the sensor for the first ~20 s after power-on (WARMUP_MS) to avoid boot-time false alarms, and uses a hysteresis band around the trip point so the alarm latches instead of chattering. The threshold (ALARM_ON/ALARM_OFF) is uncalibrated — tune it per sensor and environment.

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⚙️ How It Works

1️⃣ After a short warm-up, the MQ-2 sensor continuously monitors the air.
2️⃣ If smoke concentration exceeds the trip point, the Arduino activates the LED and buzzer.
3️⃣ The alarm clears once the smoke level falls back below the lower threshold.

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📝 Features

✅ Detects smoke and combustible gases using an MQ-2 sensor
✅ Local visual (LED) + audible (buzzer) alert
✅ Sensor warm-up gate avoids false alarms at power-on
✅ Hysteresis prevents alarm chatter near the threshold

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🌍 Applications

🔹 Fire Alarm System – Early warning for fire hazards.
🔹 Gas Leak Detection – Detects combustible gases in homes and workshops.
🔹 Kitchen Safety – Alerts users of excess smoke while cooking.
🔹 Workshop / Garage Monitoring – A simple standalone smoke alert.

ℹ️ This is a standalone local alert (LED + buzzer) with no networking. Remote/IoT monitoring or home-automation integration would be a future extension, not part of this build.