The KY-018 light detection sensor module is a device that allows you to detect the presence or absence of light using an Arduino or other microcontroller. It consists of a light-dependent resistor (LDR) and a voltage divider circuit that outputs a voltage proportional to the amount of light detected. The module typically includes a 3-pin connector, with the LDR connected to one of the pins and the other two pins connected to the voltage divider circuit. It is often used in projects that require the detection of light levels, such as automatic lighting systems, security alarms, and light-controlled displays. The output of the module can be read by an analog input pin on the microcontroller, and the microcontroller can use this information to make decisions and control other devices based on the light level detected.

This 3-pin optical sensor uses a simple LDR (Light Dependant Resistor) to directly interact with your Arduino project.

Arduino KY-018 Photoresistor module, used to measure light intensity.