Abstract
In this paper, an intelligent dimming LED nightlight is introduced, it can simulate moonlight and automatically adjust its own brightness according to environment light intensity. Photosensitive resistor module detects external light. Then, the detected intensity converts to a digital value through an AD converter module. This digital value is inputted to a microcontroller, and a PWM wave whose duty cycle can be adjusted is produced to control the brightness of the LED light. According to the relationship among color temperature, illumination and sleep quality, our LED nightlight can simulate the moonlight, output the most appropriate illumination and color temperature for sleep. From the simulation result, it can be seen clearly that with the environment light changes from bright to dark, LED light intensity changes from weak to strong real-timely. The effectiveness of the proposed method has been proved with experiments.