LED自适应调光系统设计.doc

PAGE II PAGE III （2011届） 毕业设计 题 目： 基于AVR单片机的LED自适应调光系统设计 姓　　名：　　 　　　　　 　　 专　　业：　　 电子信息工程 　　　 班　　级：　　　　 　 　 学 号： 指导教师：　　　　　 　　　 导师职称：　　　　　 　 　　　 　　　　 　年　 月 　日 PAGE I 基于AVR单片机的LED自适应调光系统设计 摘 要 作为一种光源，调光是很重要的。不仅是为了在家居中得到一个更舒适的环境，在今天来说，减少不必要的电光线，以进一步实现节能减排的目的是更加重要的一件事。而且对于LED光源来说，调光也是比其他荧光灯、节能灯、高压钠灯等更容易实现，所以更应该在各种类型的LED灯具中加上调光的功能。 自适应调光系统硬件电路由四个部分组成：感光电路、AD转换电路、单片机控制电路、发光二极管驱动电路。软件部分采用PID算法，自动调节环境光照度。本设计以89C51单片机为控制器，利用光敏电阻采集环境光照度，采用脉宽调制方式调节三极管，进而调节LED的发光亮度，最终维持环境光照度在一个设定的水平。 关键词：LED，自适应调光，AVR单片机,PID算法 LED Adaptive Dimming System Based on AVR Abstract The quality of dimming of light source is very important. It is not only for a better environment at home. At present, it is also an even more important issue to lessen waste of unnecessary electric light and further achieve the goal of energy saving and emission reduction. What’s more, for light source of LED, it is easier to adjust brightness than fluorescent lamp, energy saving lamp, high pressure sodium lamp and other kinds of lamps. Therefore, we’d better add the function of brightness-adjusting to various kinds of LED lamps. The hardware of adaptive adjustable optical-intensity system is consisted of four parts. They are photosensitive circuit, AD change-over circuit, single-chip microcomputer control circuit, and LED driving circuit. And the software of the system makes use of PID algorithm to adjust brightness of environment automatically. This design takes 89C51 SCM as controller, use photo conductive resistance to collect luminance of the environment. And the designer adopt pulse width modulation mode to adjust triode, which can help adjust brightness of LED to keep intensity of illumination of the environment at a set level. Keywords: LED, adaptive dimmer, AVR, PID 目录 TOC \o 1-3 \h \z \u HYPERLINK \l _Toc294610309 摘 要 PAGEREF _Toc294610309