基于nRF401的无线呼叫服务系统设计

Design of Wireless Calling Service System Based on nRF401

无线呼叫服务系统为点对多点通信,存在信道冲突问题。文中采用呼号广播的方法分配信道,即以中央控制器广播各呼叫器的编码呼号,统一了时分复用的计时基准点和计时时钟,实现各受服务时间片的准确分配。系统硬件设计本着低成本原则,呼叫器以AT89C2051和nRF401为核心,并做到零功耗空闲,中央控制器结构与呼叫器基本相同,以七彩LED(发光二极管)和数码管进行呼叫显示,并通过串行口与PC机相连接。基于VC++设计服务系统软件安装于PC机上,以激活的消息框提醒需要服务客人的编号。

The wireless calling service system is a kind of one point to multipoint communication,which has the problem of channel collision.This paper introduces a method of call letters broadcast to distribute the channel, which depends on the call letters broadcast fromthe center control to the caller to unify the time data mark and the timepiece of TDM,thereby the precise distribution of served time slice is realized. The system hardware is designed with the low cost principle.The caller, which is zero power consuming during theidle time, has the AT$9C2051 and nRF401 as its core.The center control has the similar structure with the caller, which shows the call with the muhicolor LED and display, and communicates with PC through the serial port. The software of the service system designed with VC ＋ ＋is installed in the PC, which can display the number of customer who needs services of message.