基于单片机的照度稳定可调台灯设计

The Stable and Adjustable Illuminance Design for the Table Lamp Based on Single-Chip Microcomputer

制作了一款照度稳定可调的LED台灯,系统以STM32F103VCT6为控制核心,根据用户设置,首先采集环境照度,通过PID算法得出对应的控制量,再通过驱动电路控制照度输出,实现照度自动稳定,不随环境光照改变而改变。采用恒流源驱动LED灯板,恒流源可以方便调节照度,同时能源效率高,恒流源使用开关电源管理芯片LM25976设计,开关电源芯片可以有效提高效率。照度采集使用BH1750芯片,BH1750是16位数字输出型,用于两线式串行总线接口的数字型光强度传感器集成电路。实现LED台灯照度稳定且连续可调,无频闪,电源效率高,同时LED台灯能自动检测环境光的强度变化,实时调节自身亮度,保持照度稳定。

A LED table lamp with adjustable illuminance is designed for this project.The system takes the STM32F103VCT6 as the control core.According to user’s setting,the system acquires ambient light,outputs the corresponding control amount based on PID algorithm,and then controls the illuminance output via the driving circuit to achieve automatic illuminance stability independent of ambient light.The LED lamp board is driven by constant current source featured with convenient illuminance adjustment and high energy efficiency.The constant current source adopts switching power supply management chip LM25976 design to improve effi-ciency.Illuminance acquisition uses BH1750 chip(16-bit digital output)for a digital light intensity sensor integrated circuit with two-wire serial bus interface.In this way,stable and continuously adjustable illumination for the LED table lamp with no flicker and high power efficiency is realized.Also,it enables the LED table lamp to detect the intensity change of ambient light automatically and adjust its own light in real time to maintain illuminance stability.