HOW to Make a Fire Alarm with ESP32

Description

In this experiment, we will make a fire alarm system. Just use a flame sensor to control an active buzzer to emit sounds.

Required Components

Connection Diagram

Test Code

from machine import Pin
import time

buzzer = Pin(15, Pin.OUT)
sensor = Pin(4, Pin.IN)

while True:
    Val = sensor.value()
    print(Val)
    if Val == 0:
        buzzer.value(1)
    else:
        buzzer.value(0)
    time.sleep(0.5)

Code Explanation

This flame sensor uses an analog pin and a digital pin. When a flame is detected, the digital pin outputs a low level. In this experiment we will use the digital port.

Test Result

Connect the wires according to the experimental wiring diagram and power on. Click “Run current script”, the code starts executing. When the sensor detects the flame, the external active buzzer will emit sounds, otherwise the active buzzer will not emit sounds.

Press “Ctrl+C”or click “Stop/Restart backend”to exit the program.