请问数码管动态显示为什么必须要延迟呢？

ID:1805 · 发表于 2012-6-9 01:11

以下是个简单的数码管动态显示的C语言程序，
假如我们把延时的delay（2）;这个去掉，结果虽然从逻辑上讲是没问题的，但是下载到板上后，看到显示比较模糊，一些不该亮的地方也有点亮。
这是为什么呢？

1 #include ＜reg52.h＞
2 sbit DUAN = P2^6;
3 sbit WEI = P2^7;
4
5 void delay(unsigned int z) //1ms延时
6 {
7     unsigned int x,y;
8     for(x=z;x＞0;x--)
9         for(y=110;y＞0;y--);
10 }
11
12 void main()
13     {
14     unsigned char code show[] = {0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07};
15     unsigned int i,which;
16     while(1)
17         {
18         which = 1;
19         for(i=0; i＜8; i++)
20             {
21             DUAN = 1;
22             P0 = show;
23             DUAN = 0;
24             P0 = 0XFF;
25             WEI = 1;
26             P0 = 255-which;
27             WEI = 0;
28             which *= 2;
29             //delay(2);
30             }
31         }
32
33     }
34
35

delay函数还是有点浪费资源，改为定时器来完成延时，
以下是刚调试好的60秒倒计时。就是在调试这个程序时遇到了前面提到的数码管模糊现象。

1 #include ＜reg52.h＞
2
3 #define uchar unsigned char
4 #define uint unsigned int
5 #define LED_LOCK openLed = 1
6 #define MATRIX_LOCK P2 = 0x35
7 #define N 2
8 //N是显示位数。
9 #define START 59
10 #define TIMER_NUM 1000
11
12 uchar tmp[] = {0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f}; //数码管0～9编码
13
14 uint timer1 = 0; timer2 = 0;
15
16 sbit led1 = P0^0;
17 sbit openLed = P1^4;
18 sbit Duan = P2^6;
19 sbit Wei = P2^7;
20
21
22 void main()
23     {
24     uint whichOne = 0;
25     uchar select[]={0xff - 1, 0xff - 2, 0xff - 4, 0xff - 8, 0xff-16, 0xff-32, 0xff-64, 0xff-128},
26         show[2],
27         num = START;
28     //select：位选编码
29     LED_LOCK;
30     MATRIX_LOCK;
31
32     TMOD = 0x01;
33     TH0 = (65536 - TIMER_NUM) ＞＞ 8;
34     TL0 = (65536 - TIMER_NUM) % 256;
35     EA = 1;
36     ET0 = 1;
37     TR0 = 1;
38
39     while(1)
40         {
41         if(timer1 ＞= 1000)
42             {
43             if(num == 0)
44                 num = START + 1;
45             num--;
46             timer1 = 0;
47             }
48
49         if(timer2 ＞= 10)
50             {
51             whichOne++;
52             whichOne %= N;
53             show[0] = num / 10;
54             show[1] = num % 10;
55             Duan = 1;
56             P0 = tmp[show[whichOne]];
57             Duan = 0;
58             P0 = 0xff;
59             Wei = 1;
60             P0 = select[whichOne];
61             Wei = 0;
62             timer2 = 0;
63             }
64         }
65
66     }
67
68 void Timer0() interrupt 1
69     {
70     TH0 = (65536 - TIMER_NUM) ＞＞ 8;
71     TL0 = (65536 - TIMER_NUM) % 256;
72     timer1 ++;
73     timer2 ++;
74     }

[此贴子已经被作者于2012-6-9 12:19:33编辑过]