#include"reg52.h"
unsigned char code table[]={0xfe,0xfc,0xf0,0xe0,0xc0,0x80,0x00};
void main()
{
unsigned char i;
while(1)
{
i++;
i&=0x07;
P1=table;
}
}
低電平點(diǎn)亮LED，i=0到7；
while循環(huán)周期*8=PWM的周期
當(dāng)i=0時(shí)，D0亮
當(dāng)i=1時(shí)，D0,D1亮
當(dāng)i=2時(shí)，D0,D1,D2亮
。。。。。。
當(dāng)i=7時(shí)，D0,D1,D2,D3,D4,D5,D6,D7全亮
也就是說(shuō)，在while的8個(gè)循環(huán)中，D0一直亮，D1則只有7次亮。。。。。。D7則只有1次亮
按照這個(gè)算法，只要定義一個(gè)一維表格，就可以靜態(tài)現(xiàn)實(shí)LED的8個(gè)不同亮度，且亮度次序任意
如果定義一個(gè)二維表格，則可以動(dòng)態(tài)現(xiàn)實(shí)LED亮度，幾乎可以任意定義次序花樣
下面來(lái)看一個(gè)完整的二維數(shù)組漸變程序
完整代碼下載地址：http://m.raoushi.com/f/jianb.rar
#include "reg52.h"
unsigned char code table[37][8]= //定義一個(gè)2維數(shù)組
{0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,//off
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xfe,//D0亮度等級(jí)1/8
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xfc,//D1亮度等級(jí)1/8
0xff,0xff,0xff,0xff,0xff,0xff,0xfd,0xfc,//D1亮度等級(jí)2/8
0xff,0xff,0xff,0xff,0xff,0xff,0xfd,0xf8,//D2亮度等級(jí)1/8
0xff,0xff,0xff,0xff,0xff,0xff,0xf9,0xf8,//D2亮度等級(jí)2/8
0xff,0xff,0xff,0xff,0xff,0xfb,0xf9,0xf8,//D2亮度等級(jí)3/8
0xff,0xff,0xff,0xff,0xff,0xfb,0xf9,0xf0,//D3
0xff,0xff,0xff,0xff,0xff,0xfb,0xf1,0xf0,
0xff,0xff,0xff,0xff,0xff,0xf3,0xf1,0xf0,
0xff,0xff,0xff,0xff,0xf7,0xf3,0xf1,0xf0,
0xff,0xff,0xff,0xff,0xf7,0xf3,0xf1,0xe0,//D4
0xff,0xff,0xff,0xff,0xf7,0xf3,0xe1,0xe0,
0xff,0xff,0xff,0xff,0xf7,0xe3,0xe1,0xe0,
0xff,0xff,0xff,0xff,0xe7,0xe3,0xe1,0xe0,
0xff,0xff,0xff,0xef,0xe7,0xe3,0xe1,0xe0,
0xff,0xff,0xff,0xef,0xe7,0xe3,0xe1,0xc0,//D5
0xff,0xff,0xff,0xef,0xe7,0xe3,0xc1,0xc0,
0xff,0xff,0xff,0xef,0xe7,0xc3,0xc1,0xc0,
0xff,0xff,0xff,0xef,0xc7,0xc3,0xc1,0xc0,
0xff,0xff,0xff,0xcf,0xc7,0xc3,0xc1,0xc0,
0xff,0xff,0xdf,0xcf,0xc7,0xc3,0xc1,0xc0,
0xff,0xff,0xdf,0xcf,0xe7,0xe3,0xc1,0x80,//D6
0xff,0xff,0xdf,0xcf,0xe7,0xe3,0x81,0x80,
0xff,0xff,0xdf,0xcf,0xe7,0x83,0x81,0x80,
0xff,0xff,0xdf,0xcf,0x87,0x83,0x81,0x80,
0xff,0xff,0xdf,0x8f,0x87,0x83,0x81,0x80,
0xff,0xff,0x9f,0x8f,0x87,0x83,0x81,0x80,
0xff,0xbf,0x9f,0x8f,0x87,0x83,0x81,0x80,
0xff,0xbf,0x9f,0x8f,0x87,0x83,0x81,0x00,//D7
0xff,0xbf,0x9f,0x8f,0x87,0x83,0x01,0x00,
0xff,0xbf,0x9f,0x8f,0x87,0x03,0x01,0x00,
0xff,0xbf,0x9f,0x8f,0x07,0x03,0x01,0x00,
0xff,0xbf,0x9f,0x0f,0x07,0x03,0x01,0x00,
0xff,0xbf,0x1f,0x0f,0x07,0x03,0x01,0x00,
0xff,0x3f,0x1f,0x0f,0x07,0x03,0x01,0x00,
0x7f,0x3f,0x1f,0x0f,0x07,0x03,0x01,0x00,
};
void main()
{
unsigned char i;
unsigned int j;
unsigned int counter;
bit flag=0;
while(1)
{
i++;
i&=0x07; //i=0到7
counter++;
if(counter==12000) //延時(shí)對(duì)j++
{
if(flag==0) j++;
else j--;
counter=0;
if(j==36 || j==0)
{
flag=!flag; //決定正向掃描還是逆向掃描
i=0;
}
}
P1=table[j]; //掃描第i列，掃描第j行
}
}
注意：用2003時(shí)，是高電平點(diǎn)亮LED。要對(duì)它取反。