基于单片机的固定电话未接来电告警系统设计

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中图分类号：TN929.5 文献标识码：A 文章编号：2096-4706（2026）05-0193-06

Design of a Missed Call Alarm System forLandline Phones Based on a Single-chip Microcomputer

HU Jiayao （Maynooth International Engineering College，Fuzhou University，Fuzhou ， China）

Abstract： To address the lack of missed callalerts in most existing landline phones， which can lead to missed important calls，a soundand light alarmsystem for landline missedcals based onan AVR microcontroller（ATmegal6）is designed andimplemented.Thesystem processs the telephonelinesignal throughapreconditioningcircuit forvoltagereductionand level shifting.TheADCmoduleof single-chip microcomputersamples andanalyzes the featuresof the processed signal， accuratelyidentifyingtelephonestates-idle，ringing，of-ook，andon-hook-usingaFinite State Machine （FSM）model.When aring isdetected withoutasubsequentof-hook action withinasettime，the systemactivatesaudibleand visualalarms Viaan optocoupler-isolateddriver circuit.Testresultsdemonstratethatthesystemaccuratelyidentifiesstatesacrossvarious caling scenariosandiggersalsliablyectivelylertinguserstomissedcallandterebyeducingpotentialsksoated with unanswered calls.

Keywords： landline phone; missed call; Single-chip Microcomputer; alarm system

0 引言

单片机是一种集成了中央处理器（CPU）、存储器、输入/输出接口及各种外设功能的微型计算机系统，它具有体积小、功耗低、成本较低、可编程性强等特点。（剩余6161字）