01
Introduction
The flame sensor is commonly used to detect flames or infrared light of specific wavelengths (760nm-1100nm). It has a detection angle of approximately 60° and is particularly sensitive to the flame spectrum. The sensitivity is adjustable (as shown by the blue potentiometer in the image). The detection distance for flames is related to sensitivity and flame intensity, generally within 1 meter. It has strong applicability and is suitable for fields such as industrial automation, safety monitoring, fire warning, and robotics.
02
Principle
The flame sensor can detect infrared light with wavelengths ranging from 700 nanometers to 1000 nanometers, with a detection angle of 60°. The sensitivity reaches its maximum when the infrared light wavelength is around 880 nanometers. The far-infrared flame probe converts the variations in external infrared light intensity into changes in current, which are reflected as changes in values within the range of 0 to 255 through an A/D converter. The stronger the external infrared light, the smaller the value; the weaker the infrared light, the larger the value.
03
Wiring
- G: Power negative, connect to GND, gray wire
- +: Power positive, connect to 3.3V, red wire
- DO: Digital signal line, connect to P0, blue wire
- AO: Analog signal line, connect to P1, yellow wire
04
Program
Program Explanation: The following program can be used for flame detection. If a flame is detected nearby, the L2 light will turn on, the micro:bit will display an X, and an alarm sound will be emitted. Simply connect to the DO port, with the digital output connected to the P0 pin, and store it in the variable sun. If num equals 1023, it will display X and play a sound.
Note: When conducting experiments, the light from the desk lamp contains infrared light, which can affect the test results. You can adjust the angle of the probe relative to the desk lamp to 90 degrees to avoid this situation!
