The LDR Sensor Module is used to detect the presence of light / measuring the intensity of light. The output of the module goes high in the presence of light and it becomes low in the absence of light. The sensitivity of the signal detection can be adjusted using potentiometer.

Features:-

• Can detect ambient brightness and light intensity
• Adjustable sensitivity (via blue digital potentiometer adjustment)
• Operating voltage 3.3V-5V
• Output Type

Analog voltage output -A0
Digital switching outputs (0 and 1) -D0 

• With fixed bolt hole for easy installation
• Small board PCB size: 3cm * 1.6cm
• Power indicator (red) and the digital switch output indicator (green)
• Using LM393 comparator chip, stable

Pin outs:-

• External 3.3V-5V VCC
• External GND GND
• DO digital output interface, a small plate (0 and 1)
• AO small board analog output interface

How to use:-

• Photosensitive resistor module most sensitive to environmental light intensity is generally used to detect the ambient brightness and light intensity.
• Module light conditions or light intensity reach the set threshold, DO port output high, when the external ambient light intensity exceeds a set threshold, the module D0 output low;
• Digital output D0 directly connected to the MCU, and detect high or low TTL, thereby detecting ambient light intensity changes;
• Digital output module DO  can directly drive the relay module, which can be composed of a photoelectric switch;
• Analog output module AO and AD modules can be connected through the AD converter, you can get a more accurate light intensity value