以下是個(gè)簡單的數(shù)碼管動(dòng)態(tài)顯示的C語言程序，
假如我們把延時(shí)的delay（2）;這個(gè)去掉，結(jié)果雖然從邏輯上講是沒問題的，但是下載到板上后，看到顯示比較模糊，一些不該亮的地方也有點(diǎn)亮。
這是為什么呢？
1 #include ＜reg52.h＞
2 sbit DUAN = P2^6;
3 sbit WEI = P2^7;
4
5 void delay(unsigned int z) //1ms延時(shí)
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函數(shù)還是有點(diǎn)浪費(fèi)資源，改為定時(shí)器來完成延時(shí)，
以下是剛調(diào)試好的60秒倒計(jì)時(shí)。就是在調(diào)試這個(gè)程序時(shí)遇到了前面提到的數(shù)碼管模糊現(xiàn)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是顯示位數(shù)。
9 #define START 59
10 #define TIMER_NUM 1000
11
12 uchar tmp[] = {0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f}; //數(shù)碼管0～9編碼
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：位選編碼
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 }
[此貼子已經(jīng)被作者于2012-6-9 12:19:33編輯過]
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