多功能自动拨号报警系统设计研究

摘要

This paper introduces a multi-function automatic dial-up alarm system which bases on the AT89S51,and it gives the system hardware diagram and program flow chart.The system is capable of detecting phone line disconnected,can modify the default phone number arbitrarily,can correctly receive and distinguish Alarm signal from pyroelectric infrared alarm sensor,toxic gas sensors and smoke sensors through wireless way,when single-chip microcomputer detects above alarm signal,it immediately start pick/hang up circuit,and Pre-configured telephone number of the corresponding is removed one by one from the AT24C02 memory,then by a frequency decoding chips MT8880 to send DTMF dual tone multi-frequency signal,and complete automatic dial-up function,if the other person hang up,it automatically play corresponding voice alarm information which has been recorded in the voice chip;If the stored numbers were not connected,then start alarm,to avoid the buzzer things further expansion and decrease the losses.The system is especially suitable for homes and offices.%介绍以AT89S51单片机为核心的多功能自动拨号报警系统,给出了系统硬件框图和程序流程图.该系统能够进行电话线的断线检测,能够任意修改预设电话号码,能通过无线方式准确接收到并区分来自热释红外防盗传感器、有毒气体传感器和烟雾传感器的报警信号,当单片机检测到上述报警信号时,立即启动摘/挂机电路摘机,并从AT24C02存储器里逐个取出预设定好的相应的电话号码,再通过双音多频编解码芯片MT8880发送DTMF双音多频信号,完成自动拨号功能,若对方摘机,则自动播放已经录制在语音芯片中的相应的语音报警信息;若预存的号码均未接通,则启动蜂鸣器报警,避免事态的进一步扩大,减小损失.该系统特别适用于家庭和办公室.