目录
摘要 ................................................................I
Abstract ...........................................................II
1、引 言 ...........................................................1
2、设计方案 .........................................................2
3、电路基本知识 .....................................................3
3.1.1、RS-232 引脚及其含义 ...........................................3
3.1.2、RS-232 接口电平 ...............................................4
3.1.3、RS-232 的不足之处 .............................................4
3.2.1、RS-485 简介 ...................................................5
3.2.2、RS-485 引脚说明 ...............................................5
3.2.3、RS-485 特点 ...................................................6
3.3.1、MAX232 芯片简介 ...............................................6
3.3.2、MAX232 芯片引脚图 .............................................7
3.3.3、MAX232 引脚功能说明 ...........................................7
3.4.1、MAX485 芯片简介 ...............................................8
3.4.2、MAX485 芯片引脚图及其说明 .....................................8
3.4.3、MAX485 芯片的主要特性 ........................................10
4、单元电路设计 ....................................................11
5、电路调试 ........................................................15
6、电路实物图 ......................................................16
7、心得体会 ........................................................17
8、参考文献 ........................................................18
附录：程序 .........................................................19
