基于单片机的光功率计的设计.doc

摘要本文首先对光功率计的组成原理进行了详细的分析,查阅大量资料并比较国内外产品的性能和价格,然后根据生产的实际需要进行低成本研发工作。在能满足生产的的要求基础上进行总体的设计规划,并给出各个电路的设计和说明,包括光探测器的选择、放大滤波电路的设计、 A/D 转换、单片机控制、外围电路的设计、液晶显示电路、按键电路等设计。在选择芯片方面,我们尽量做到 IC 集成化,因为集成 IC ,我们摒弃用汇编语言开发下位机程序,而改用 C 语言,这样使得开发效率更高和程序的可读性更强。其中有下位机 MCU 自身的初始化,下位机 MCU 与外围芯片的通信,下位机与上位机的通信,上位机程序的书写等。关键词: 单片机,智能仪表,光功率计 abstract This paper first light to position of the power meter principle ofa detailed analysis, consulting a large number of material and parison of domestic and foreign products performance and price, and then based on the actual need of the production of the low cost research and development work. In satisfy the production based on the requirements of the overall design planning, and give each circuit design and shows, including the choice of light detectors, amplify filter circuit design, A/D conversion and single-chip puter control, peripheral circuit design, liquid crystal display circuit, key circuit design. In the choice of chips, we try todo IC integration, because the integrated function of the integrated IC more stable and the price is relatively cheap. The last of the system is different models of the software to write, we abandoned in assembly language development a program under the machine, toC language, this makes the efficiency of development in higher and the program more readable. Among them are a machine itself under the initialization of MCU, a machine and munications chip MCU, superordination munication, PC program of writing, etc. Key words: a single-chip puter, intelligent instrument, light power meter 1 绪论近年来,光纤通信已成为通信领域发展中的最前沿,它不仅在军用,而且在民用通信中也得到广泛应用。光纤通信系统的主要组件有: (1) 光缆:它由一根或多根光纤、或光纤束制成的符合光通信要求的线缆。(2) 光源:通常是可见光或红外光,常用光源是发光二极管(LED) 和固体激光器。其光信号可以被调制,以使模拟信号或数字信号加至该光源的光束上。(3) 检测器:它位于接收端,可将光信号转换为电信号。常用的检测器有 PIN 光电二极管或雪崩光电二极管,PIN 光电二极管对低频信号有整流作用,但对射频信号和微波信号只有阻抗作用,因此可用来对信号进行控制。加反偏压或无偏压时, PIN 的阻抗都很高。加正偏压时,载流子注入中间层,阻抗迅速变低。(4) 连接口:光源到光缆的接口或光缆至检测器的接口都需要高效光学连接器,否则连接处会产生很大的信号损失。(5) 标准通信电路:它位于光源前部和光检测器后部。八五一