The light sensor module KY-018 is a light dependent resistor or LDR that can be easily connected to any Arduino analog input. The provides an analog signal that varies with the amount of visible light received and it can be used natural light at indoors or outdoors or artifitial light and even infrared or ultraviolet light (less sensitive). By combining two of these sensors, you can implement a classic light following robot.
In darkness, the approximate resistor value of the LDR is very high (approximately of 1MΩ), while this value decreases dramatically with light depending on light intensity. The internal resistor included in the module acts as a voltage divider.
- Voltage: 5V.
- Sensitive to three light spectrums: ultraviolet, infrared and ambient.
- S: Analog signal.
- Pin2: +5V.
- -: Ground (0v).