Description

Photo resistors, also known as light dependent resistors (LDR), are light sensitive devices most often used to indicate the presence or absence of light, or to measure the light intensity. In the dark, their resistance is very high, sometimes up to 1MΩ, but when the LDR sensor is exposed to light, the resistance drops dramatically, even down to a few ohms, depending on the light intensity. LDRs have a sensitivity that varies with the wavelength of the light applied and are nonlinear devices. They are used in many applications but are sometimes made obsolete by other devices such as photodiodes and phototransistors.

Required Hardware Devices

• Arduino controller × 1
• KY-018 Photo Resistor
• USB data cable × 1

Connecting

• Arduino A5 –> Module Signal (S)
• Arduino 5V –> Module +5V (Pin2)
• Arduino GND –> Module GND (-)

Code