以下程序在 16×16 点阵 LED 上依次显示“梅川酷子”四个字，分别用 正向显示和反向显示，间隔两秒钟变换一次，电路图和效果图下图所示。 AT89 c52 晶振频率为 24MHz，用 T0 定时，改变变量 flag 值，从而让程序确定显示哪 个汉字和显示方式（正向 or 反向）。 ＃include 或者#include #define int8 unsigned char #define int16 unsigned int #define int32 unsigned long int8 flag; /* flag 变量 MSB 7 6 × × 5 4 3 2 × 1 0 LSB Bit5＝1，Bit4=0 时，负向显示 Bit5＝0，Bit4=1 时，负向显示 Bit[2..0]74HC138 的片选信号 */ int8 n; int8 code table[][32]={ {0x88,0x00,0x88,0x00,0x88,0x7F,0x48,0x00,0xDF,0x1F,0xA8,0x10,0x9C,0x1 2,0xAC,0x14,0xEA,0x7F,0x8A,0x12,0x89,0x14,0x88,0x10,0x88,0x7F,0x08,0x 10,0x08,0x14,0x08,0x08},/*"梅",0*/ {0x08,0x20,0x08,0x21,0x08,0x21,0x08,0x21,0x08,0x21,0x08,0x21,0x08,0x2 1,0x08,0x21,0x08,0x21,0x08,0x21,0x08,0x21,0x08,0x21,0x08,0x21,0x04,0x 21,0x04,0x20,0x02,0x00},/*"川",1*/ {0x00,0x08,0xFE,0x08,0x28,0x0A,0x28,0x7E,0xFE,0x0A,0xAA,0x09,0xAA,0xF F,0xEA,0x00,0x86,0x00,0x82,0x7E,0xFE,0x42,0x82,0x42,0x82,0x42,0xFE,0x 7E,0x82,0x42,0x00,0x00},/*"酷",2*/ {0x00,0x00,0xF8,0x1F,0x00,0x08,0x00,0x04,0x00,0x02,0x00,0x01,0x00,0x0 1,0x00,0x41,0xFE,0xFF,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x 01,0x40,0x01,0x80,0x00}/*"子",3*/ }; void delay(void); void main(void){ int8 i; int8 j; int8 index; 

flag=0x10; n=0; //定时器 T0 初始化 TMOD=0x01; TH0=0xb1; TL0=0xe0; ET0=1; EA=1; TR0=1; while(1) { index=flag&0x03; if((flag&0x30)==0x10) { //正向显示 for(i=0;i<8;i++) { //显示上半屏 P0=table[index][2*i]; //左上 P2=i|0x08; delay(); P0=table[index][2*i+1]; //右上 P2=i|0x10; delay(); } for(i=8;i<16;i++) { //显示下半屏 P0=table[index][2*i]; //左下 P2=(i-8)|0x20; delay(); P0=table[index][2*i+1]; //右下 P2=(i-8)|0x40; delay(); } 

} if((flag&0x30)==0x20) { //反向显示 for(i=0;i<8;i++) { P0=~(table[index][2*i]); //左上 P2=i|0x08; delay(); P0=~(table[index][2*i+1]); //右上 P2=i|0x10; delay(); } for(i=8;i<16;i++) { P0=~(table[index][2*i]); //左下 P2=(i-8)|0x20; delay(); P0=~(table[index][2*i+1]); //右下 P2=(i-8)|0x40; delay(); } } } } void delay(void){ int16 i; for(i=0;i<50;i++); } void timer0() interrupt 1 using 3 { TF0=0; TH0=0xb1; 

TL0=0xe0; if(n<200) { //10ms 中断一次 n++; } else { //2 秒改变一次 switch(flag) { case 0x10: { } { } { } { } { } { } { flag=0x11;//下次显示正向“川” break; case 0x11: flag=0x12;//下次显示正向“酷” break; case 0x12: flag=0x13;//下次显示正向“子” break; case 0x13: flag=0x20;//下次显示负向“川” break; case 0x20: flag=0x21;//下次显示负向“梅” break; case 0x21: flag=0x22;//下次显示负向“酷” break; case 0x22: flag=0x23;//下次显示负向“子” break; 

case 0x23: flag=0x10;//下次显示正向“梅” break; } { } } n=0; } }