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楼主 |
发表于 2011-3-8 13:43:31
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#include <avr/io.h>
#include <avr/delay.h>
unsigned char led_7[10]={0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F};
unsigned char position[6]={0x20,0x10,0x08,0x04,0x02,0x01};
unsigned char time[3]; // 时、分、秒计数
unsigned char dis_buff[6]; // 显示缓冲区,存放要显示的6个字符的段码值
unsigned char time_counter; // 1秒计数器
unsigned int point_on; // 秒显示标志
void display(void) // 扫描显示函数,执行时间12ms
{
unsigned char i;
for(i=0;i<=5;i++)
{
PORTA = led_7[dis_buff];
if (point_on && ( i==2 || i==4 )) PORTA |= 0x80; // (1)
PORTC = position;
_delay_ms(2); // (2)
PORTC = 0x00; // (3)
}
}
void time_to_disbuffer(void) // 时间值送显示缓冲区函数
{
unsigned char i,j=0;
for (i=0;i<=2;i++)
{
dis_buff[j++] = time % 10;
dis_buff[j++] = time / 10;
}
}
int main(void)
{
PORTA=0x00; // PORTA初始化
DDRA=0xFF;
PORTC=0xC0; // PORTC初始化
DDRC=0x3F;
time[2] = 11; time[1] =34; time[0] = 52; // 时间初值23:58:55
time_to_disbuffer();
while (1)
{
display(); // 显示扫描,执行时间12ms
if (++time_counter >= 40)
{
time_counter = 0; // (4)
point_on = ~point_on; // (5)
if (++time[0] >= 60)
{
time[0] = 0;
if (++time[1] >= 60)
{
time[1] = 0;
if (++time[2] >= 24) time[2] = 0;
}
}
time_to_disbuffer();
}
_delay_ms(13); // 延时13ms,可进行其它处理(6)
}
}
此代码《AVR单片机嵌入式系统原理与应用实践》中6.5节移植过来的 |
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