单片机频率计的毕业设计.doc

摘 要 随着电子信息产业的不断发展，信号频率的测量在科技研究和实际应用中的作用日益重要。科技的日新月异的高速发展，传统的频率计通常是用很多的逻辑电路和时序电路来实现的，这种电路一般运行较慢，而且测量频率的范围较小。现在的客户对电子频率的测量也提出了新的要求，对于低档产品要求使用操作方便，量（够）宽，可靠性高，价格低。而对于中高档产品， 则要求有高分辨率，高精度，高稳定度，高测量速率；除通常通用计数器所具有的功能外，还要有数据处理功能，统计分析功能，时域分析功能等等，或者包含电压测量等其他功能。这些要求有的已经实现或者部分实现，但要真正完美的实现这些目标，对于生产厂家来说，还有许多工作要做，而不是表面看来似乎发展到头了。 考虑到上述问题，本论文设计一个基于STC89C52单片机设计的频率计。首先，我们把待测信号经过放大整形，然后把信号送入单片机的定时计数器里进行计数，获的频率值，最后把测得的频率数值送入显示电路里进行显示。本文从频率计的原理出发，介绍了基于单片机的频率计的设计方案，选择了实现系统的各种电路元器件。 关键词：单片机 频率 测量 精度 ABSTRACT With the development of the electronic information industry, the signal frequency measurement in science and technology research and practical application is increasingly important. Rapid development of science and technology of the high speed development, the traditional frequency is usually a lot of program logic circuit and the sequential circuits to implementation, this circuit, generally run slower, and measurement of the frequency of the small areas. Now the customers on the electronic frequency measurement has also put forward new requirements, low product requirements to use convenient operation, quantity (enough) wide, high reliability and low price. And for high-grade goods, it require a high resolution, high precision, high stability, high measurement rate; In addition to general counter usually have the functions, but also a data processing functions, statistical analysis function, the time domain analysis function and so on, or contain voltage measurement, and other functions. These requirements have been implemented or partially realized some, but to really perfect achieve these goals, for manufacturers for, there is still a lot more work to do, and not surface appear to development limited. In view of the above problems, this paper designed a STC89C52 based on SCM design project of frequency. First of all, we have to be measured signal after plastic surgery to enlarge, then the signal to the timing of the single chip microcomputer counter to count for frequency v