Documentation

// KY-026 Flame Sensor - Arduino Example
// A0 -> A0, D0 -> Digital Pin 2, + -> 5V, G -> GND

const int analogPin = A0;   // analog IR intensity
const int digitalPin = 2;   // comparator flame output

void setup() {
  Serial.begin(9600);
  pinMode(digitalPin, INPUT);
}

void loop() {
  // Read raw IR intensity (0-1023)
  int analogValue = analogRead(analogPin);

  // Read the comparator output: HIGH = flame above threshold
  int flameState = digitalRead(digitalPin);

  Serial.print("Analog: ");
  Serial.print(analogValue);

  if (flameState == HIGH) {
    Serial.println("  |  FLAME DETECTED!");
  } else {
    Serial.println("  |  No flame");
  }

  // Watch the analog value with and without a flame to learn
  // your board's baseline, then adjust the potentiometer so
  // D0 triggers exactly when you want it to.
  delay(500);
}

# KY-026 Flame Sensor - ESP32 MicroPython Example
# A0 -> GPIO 34, D0 -> GPIO 25, + -> 3V3, G -> GND

from machine import ADC, Pin
import time

# GPIO 34 is an ADC1 channel, so it keeps working with Wi-Fi on
analog = ADC(Pin(34))
analog.atten(ADC.ATTN_11DB)   # full 0 - 3.3V input range

digital = Pin(25, Pin.IN)     # comparator flame output

while True:
    raw = analog.read()               # 0 - 4095
    voltage = raw * 3.3 / 4095

    if digital.value() == 1:
        state = "FLAME DETECTED!"
    else:
        state = "No flame"

    print("Analog: {} ({:.2f} V)  |  {}".format(raw, voltage, state))
    time.sleep(0.5)

#!/usr/bin/env python3
# KY-026 Flame Sensor - Raspberry Pi Example
# D0 -> GPIO 17 (physical pin 11), + -> 3.3V (pin 1), G -> GND (pin 6)
# The Pi has no ADC, so we use the digital output only.

import RPi.GPIO as GPIO
import time

DO_PIN = 17

GPIO.setmode(GPIO.BCM)
GPIO.setup(DO_PIN, GPIO.IN)

try:
    print("Monitoring KY-026 flame sensor (Ctrl+C to stop)...")
    last_state = GPIO.input(DO_PIN)

    while True:
        state = GPIO.input(DO_PIN)

        # Only print when the state changes
        if state != last_state:
            if state == GPIO.HIGH:
                print("FLAME DETECTED!")
            else:
                print("Flame no longer detected.")
            last_state = state

        time.sleep(0.1)

except KeyboardInterrupt:
    print("Stopped by user")
finally:
    GPIO.cleanup()

# KY-026 Flame Sensor - Pico MicroPython Example
# A0 -> GP26 (ADC0), D0 -> GP15, + -> 3V3(OUT), G -> GND

from machine import ADC, Pin
import time

analog = ADC(26)            # GP26 = ADC0
digital = Pin(15, Pin.IN)   # comparator flame output

while True:
    raw = analog.read_u16()          # 0 - 65535
    voltage = raw * 3.3 / 65535

    if digital.value() == 1:
        state = "FLAME DETECTED!"
    else:
        state = "No flame"

    print("Analog: {} ({:.2f} V)  |  {}".format(raw, voltage, state))
    time.sleep(0.5)