蓝桥杯之单片机学习（八）——定时器的基本原理与应用的代码展示

#include <reg52.h> typedef unsigned int uint; typedef unsigned char uchar; sbit L1 = P0^0; sbit L8 = P0^7; //配置HC138 void SelectHC138(uchar channel) { switch(channel) { case 4: P2 = (P2 & 0X1F) | 0X80; break; case 5: P2 = (P2 & 0X1F) | 0Xa0; break; case 6: P2 = (P2 & 0X1F) | 0Xc0; break; case 7: P2 = (P2 & 0X1F) | 0Xe0; break; } } //初始化系统 void Initsys() { SelectHC138(5); P0 = 0X00;//关闭蜂鸣器和继电器 SelectHC138(4); P0 = 0XFF;//关闭LED } //******************************** void InitTime0() { TMOD = 0X01; TH0 = (65535 - 50000) / 256; TL0 = (65535 - 50000) % 256; ET0 = 1; EA = 1; TR0 = 1; } uchar count = 0; void ServiceTime0() interrupt 1 { TH0 = (65535 - 50000) / 256; TL0 = (65535 - 50000) % 256; count++; if(count % 10 == 0) { L1 = ~L1; } if(count == 100) { L8 = ~L8; count = 0; } } //******************************** void main() { SelectHC138(4); InitTime0(); Initsys(); while(1) { } }