目 录
第 1 章 前言............................................................................................................................................1
1.1 题目背景及研究意义 ...............................................................................................................1
1.2 设计内容及参数要求 ...............................................................................................................2
1.2.1 设计内容 ........................................................................................................................2
1.2.2 参数要求 ........................................................................................................................2
第 2 章 方案的设计与论证....................................................................................................................3
2.1 测频原理 ...................................................................................................................................3
2.2 方案一 .......................................................................................................................................4
2.3 方案二 .......................................................................................................................................4
2.4 方案选择 ...................................................................................................................................5
第 3 章 硬件的设计................................................................................................................................6
3.1 基本设计原理 ...........................................................................................................................6
3.2 系统硬件模块关系 ...................................................................................................................6
3.2.1 系统总体 ........................................................................................................................6
3.2.2 单片机管脚说明 ............................................................................................................7
3.2.3 单片机 I/O 口分配表...................................................................................................10
3.2.4 频率显示电路 ..............................................................................................................10
3.2.5 时钟电路 ......................................................................................................................10
3.2.6 电源电路 ......................................................................................................................11
3.2.7 复位按钮 ......................................................................................................................11
3.2.8 数码管显示电路 ..........................................................................................................12
3.2.9 输入信号的要求 ..........................................................................................................14
3.3 最终的硬件电路图 .................................................................................................................15
第 4 章 软件的设计..............................................................................................................................16
4.1 程序的流程图 .........................................................................................................................16
4.2 数码管扫描部分 .....................................................................................................................19
4.3 频率计主程序 .........................................................................................................................19
第 5 章 软件与硬件调试......................................................................................................................20
5.1 C 程序编译与仿真结果 .........................................................................................................20
