74HC595最早应用于点阵显示,后来STC推广在IO端口扩展上,并取得良好的效果。现在将IO扩展应用 于数码管扫描显示上,并循序渐进的学习,让学习者一步一步掌握IO端口扩展。
仿真原理图如下(proteus仿真工程文件可到本帖附件中下载)
单片机源程序如下:
- #include"reg51.h"
- #include"595IO.h"
- #define uchar unsigned char
- #define uint unsigned int
- void delay(uchar i);
- void distime(uchar up,uchar time);
- uchar segcode[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};
- uchar digcode[]={0xef,0xdf,0xbf,0x7f};
- struct time
- {
- uchar hour;
- uchar min;
- uchar sec;
- uchar secc;
- }time1={12,0,0,0};
- void main(void)
- {
- IE=0x82;TMOD=1;
- TH0=(65536-50000)/256;
- TL0=(65536-50000)%256;
- TR0=1;
- while(1)
- {
- distime(0,time1.hour);
- distime(2,time1.min);
- }
- }
- void delay(uchar i)
- {
- uchar j;
- do
- {
- for(j=0;j<250;j++);
- }while(i--);
- }
- void distime(uchar up,uchar time)
- {
- wr595(digcode[up],segcode[time/10]);
- delay(4);
- wr595(digcode[up],0);
- if(up==0&&time1.sec%2==0)
- wr595(digcode[up+1],segcode[time%10]|0x80);
- else
- wr595(digcode[up+1],segcode[time%10]);
- delay(4);
- wr595(digcode[up+1],0);
- }
- void tt0(void) interrupt 1 using 0
- {
- TH0=(65536-50000)/256;
- TL0=(65536-50000)%256;
- time1.secc++;
- if(time1.secc==20)
- {
- time1.secc=0;
- time1.sec++;
- if(time1.sec==60)
- {
- time1.sec=0;
- time1.min++;
- ……………………
- …………限于本文篇幅 余下代码请从51黑下载附件…………
复制代码
所有资料51hei提供下载:
595IO.RAR
(70.12 KB, 下载次数: 43)
|