单片机仿真 用定时器设计的门铃.rar

#include <reg52.h> #define uchar unsigned char #define uint unsigned int sbit Key = P1^7; sbit DoorBell = P3^0; uint p = 0; void Timer0() interrupt 1 { DoorBell = ~DoorBell; p++; if(p<400) { TH0 = (8192-700)/32; TL0 = (8192-700)%32; } else if(p<800) { TH0 = (8192-1000)/32; TL0 = (8192-1000)%32; } else { TR0 = 0; P = 0; } } void main() { IE = 0x82; TMOD = 0x00; TH0 = (8192-700)/32; TL0 = (8192-700)%32; while(1) { if(Key == 0) { TR0 = 1; while(Key==0); } } }