IoT Smart Kitchen Safety System for family members in Nepal: Gas Leak & Stove Monitor

Most households in Nepal rely on liquefied petroleum gas (LPG) cylinders for cooking. Leaks from worn-out rubber hoses or old brass regulators are a major source of home fires. Additionally, leaving a stove unattended for long periods can lead to boiling over or fires.

You can construct a simple safety system that monitors gas presence, smoke levels, and stove proximity to trigger a local alarm and alert you on your phone.

Hazards to Detect

1. LPG Leakage: LPG is heavier than air and sinks. An MQ-2 or MQ-5 sensor placed near the floor level under the gas stove detects propane/butane leaks.
2. Overheating Stoves: A non-contact temperature sensor pointed at the stove detects if a pot has boiled dry and is overheating.
3. Kitchen Occupancy: A PIR sensor detects if someone is in the kitchen. If the stove is hot but no motion is detected for 15 minutes, it flags a warning.

Circuit Components

• Microcontroller: ESP32 C3 (needs to connect to home WiFi to send messages).
• Gas Sensor: MQ-2 sensor module.
• Temperature Sensor: MLX90614 infrared temperature sensor.
• Actuators: Active buzzer and a relay module to control an exhaust fan.

Core Monitoring Code

const int GAS_PIN = 34; // Analog pin for MQ-2
const int BUZZER_PIN = 12;
const int GAS_THRESHOLD = 700; // Calibrate for your kitchen

void setup() {
  Serial.begin(115200);
  pinMode(BUZZER_PIN, OUTPUT);
}

void loop() {
  int gasValue = analogRead(GAS_PIN);
  Serial.print("Gas Level: ");
  Serial.println(gasValue);

  if (gasValue > GAS_THRESHOLD) {
    // Sound local alarm
    digitalWrite(BUZZER_PIN, HIGH);
    sendAlertNotification();
  } else {
    digitalWrite(BUZZER_PIN, LOW);
  }
  delay(1000);
}

void sendAlertNotification() {
  // Call API to send message or WhatsApp
}

Deployment Guidelines

• Positioning: Mount the MQ-2 sensor low down (around 30 cm from the floor) near your LPG cylinder, because propane and butane are heavier than air and collect at floor level.
• Backup Power: Since power cuts can happen at any time, run the monitor from a 5V USB battery pack or a battery shield. This ensures it stays active even during load shedding.