IoT Gas Leakage Detector FYP: LPG & Flammable Gas with SMS Alert

Why Gas Detector Projects Score High

IoT gas detection systems are a strong FYP choice because they solve a real safety problem, they're visually impressive during demos (the alarm goes off when you hold a lighter near it), and the hardware is inexpensive.

This is also one of Rectronx Circuits' flagship project builds — the photo on our homepage shows our actual deployed gas detector with MQ2 and MQ5 sensors, OLED display, and PIR motion detection.

Components List

Component	Purpose	Cost (RM)
Arduino Uno / ESP32	Main controller	RM 20–45
MQ-2 Gas Sensor	Detect LPG, propane, smoke	RM 8–12
MQ-5 Gas Sensor	Detect natural gas, LPG	RM 8–12
OLED Display (0.96")	Show gas levels in real-time	RM 12–18
Buzzer	Audio alarm	RM 2
Red LED	Visual alarm indicator	RM 1
SIM800L / GSM Module	Send SMS alerts	RM 20–35
PIR Motion Sensor	Detect human presence (optional)	RM 8
Enclosure box	Professional housing	RM 15–25

Total: RM 100–180

System Features

A well-built gas detector FYP should include:

1. Dual sensor detection — MQ-2 for smoke/LPG, MQ-5 for natural gas
2. Real-time OLED display — show gas concentration values live
3. Threshold alarm — buzzer + LED when gas level exceeds safe limit
4. SMS alert — send warning to registered phone numbers via GSM
5. PIR integration — detect human presence in the room (bonus feature)

Circuit Wiring

MQ-2 Sensor

• VCC → 5V
• GND → GND
• AO (Analog Out) → Arduino A0
• DO (Digital Out) → Arduino D2 (for threshold interrupt)

MQ-5 Sensor

• VCC → 5V
• GND → GND
• AO → Arduino A1

OLED Display (I2C)

• SDA → A4
• SCL → A5
• VCC → 3.3V
• GND → GND

GSM Module (SIM800L)

• TX → Arduino RX (via voltage divider)
• RX → Arduino TX
• VCC → External 4V supply (not 5V)
• GND → Common GND

Code Logic

// Core logic pseudocode
void loop() {
  mq2_value = analogRead(A0);
  mq5_value = analogRead(A1);
  
  display_oled("MQ2: " + mq2_value);
  display_oled("MQ5: " + mq5_value);
  
  if (mq2_value > MQ2_THRESHOLD || mq5_value > MQ5_THRESHOLD) {
    trigger_alarm();      // buzzer + LED
    send_sms("+60XXXXXXXXX", "GAS ALERT! Check your premises immediately.");
    delay(30000);         // wait 30s before next SMS
  }
}

Calibration — Important Step

MQ sensors need calibration in clean air before use:

1. Power on the sensor
2. Wait 24–48 hours for the sensor to "burn in" (this is normal — sensors need warm-up time)
3. In clean air, read the baseline voltage (typically 0.1–0.3V)
4. Set your threshold as baseline + safety margin

Skipping calibration is the #1 reason gas detector FYPs fail during demos.

Enclosure Design

A professional enclosure makes a huge impression on examiners. Rectronx Circuits uses a standard IP56 waterproof enclosure box (155x115x80mm) with:

• Sensors mounted through drilled holes (facing outward)
• OLED display visible through a cutout
• LED indicator visible from front
• Power cable exit at rear

This is exactly what you see in our homepage photo.

Grading Tips

Feature	Marks Impact
Dual sensor (MQ2 + MQ5)	Higher than single sensor
OLED display showing live values	Visual impact on examiners
SMS alert with GSM	Real-world application marks
Calibrated threshold	Shows technical understanding
Professional enclosure	Presentation marks
IoT dashboard (Blynk/ThingSpeak)	Distinction-level feature

Need This Project?

This is one of our most-requested FYP builds. Rectronx Circuits delivers the complete gas detector system — fully assembled, calibrated, programmed, and tested — with full documentation.

WhatsApp us with your university requirements and deadline. We'll have it ready for you.

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