Design and Implementation of an LED Automatic Lighting System for Plant Factories

This paper proposed a light-emitting diode (LED) automatic lighting system for plant factories. This system can achieve the simultaneous effects of automatic dimming and seven-segment mixing; the light intensity and color can therefore be adjusted according to the properties of the plants to increase crop harvest. The operation method comprises detection of the light source through a photosensitive diode CdS, and sending the analog value obtained from the light intensity to the single chip dsPIC30F4011 for analog-to-digital conversion. This single chip stores the digital value in the internal pulse width modulation (PWM) register and outputs it to the dimming circuit to achieve the effect of automatic dimming. In addition, the operator can also connect to the system using smartphone Bluetooth and an ATmega328 single chip and manually select the color of the light source through the human–machine interface. The ATmega328 chip receives the operating signal and transfers it to the dsPIC30F4011, which automatically changes the PWM output channel to achieve seven-segment light mixing.