Fire & Gas Alarm

Overview

A flame sensor and MQ-2 watch for danger; when either trips, a buzzer sounds and a red LED lights.

Build Steps

1. 1

   Wire the sensors

   Flame sensor digital output and MQ-2 analog output to the board.

2. 2

   Warm up the gas sensor

   Let the MQ-2 heat a few minutes and log normal readings to choose a threshold.

3. 3

   Wire the alarm

   Buzzer and a red LED with a 220 Ω resistor.

4. 4

   Write the logic

   Flame or gas over threshold sounds the buzzer and lights the LED.