单工无线呼叫系统
【摘要】：
本文主要介绍以AT89S51单片机为核心的一个具有单工语音和英文数据传输功能无线呼叫系统。该系统的主站主要由单片机与双音频（DTMF）信号编码器以及锁相频率发射机组成；从站主要由由单片机与高保真调频接收机以及双音频信号解码器组成。主站与从站通过锁相频率发射机与高保真调频接收机进行通讯。双音频（DTMF）信号编码器与双音频信号解码器能对调频信号中的双音频（DTMF）信号进行调制与解调。双音频（DTMF）信号编码器与双音频信号解码器使得本系统具有数据传输能力。在传输语音信号的同时也能传输一定的数据信息，对于小型的通讯系统具有一定的适用性。
【关键词】：单片机 双音频（DTMF） 锁相环 数据传输
【Abstract】：
This article describes a radio calling system with the functions of single direction voice and data transmission which is based on the AT89S51 single chip microcomputer. The system’s master station mainly consists of the single chip, DTMF signal encoder and PLL frequency transmitter. The slave stations mainly consist of single chip, Hi-Fi FM receiver and DTMF signal decoder. The master and slave stations communicate with each other through the PLL frequency transmitter and Hi-Fi FM receiver . Both of them make the system capable of transmitting the data. The system is suitable for using in small communications systems due to the ability of its transmitting voice as well as the data in the same time.
【Key Words】：Single chip microcomputer, DTMF PLL Data transmission
目录；
一、方案比较与论证
二、系统硬件设计
三、系统软件设计
四、系统的组装
五、系统调试
