Photodiode module is most sensitive to the ambient light, generally used to detect the brightness of the ambient light intensity, photoresistor sensor module Universal In most cases, the difference between the two is that photodiode module directional, can sense the fixed the direction of the light source.
Module in the light conditions or the light intensity of less than a set threshold, DO port outputs a high level, when the external environment when the light intensity exceeds the set threshold value, the module D0 output is low.
The small board digital output D0 can be connected directly with the microcontroller microcontroller to detect high and low to detect environmental light intensity change.
Small board digital output DO OUR relay module can directly drive, which can be composed of a photoelectric switch.