led_clock.c

用atmega16做的一个时钟

/*********************************************
File name			: demo_6_5.c
Chip type           : ATmega16
Program type        : Application
Clock frequency     : 4.000000 MHz
Memory model        : Small
External SRAM size  : 0
Data Stack size     : 256
*********************************************/

#include <mega16.h>
#include <delay.h>

flash unsigned char led_7[10]={0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90};
flash unsigned char position[4]={0x08,0x04,0x02,0x01};
unsigned char time[3];					// 时、分、秒计数
unsigned char dis_buff[4];				// 显示缓冲区，存放要显示的4个字符的段码值
unsigned char time_counter;				// 1秒计数器
bit 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<=3;i++)
	{
		PORTB = led_7[dis_buff[i]]; 
		if (point_on && ( i==2)) PORTB &= 0x7F;	
		PORTA = position[i]; 
       	        delay_ms(3);									
       	        PORTA = 0x00;								
  	}
}

void time_to_disbuffer(void)			// 时间值送显示缓冲区函数
{
	unsigned char i,j=0;
	for (i=1;i<=2;i++)
	{
		dis_buff[j++] = time[i] % 10;
		dis_buff[j++] = time[i] / 10;
	}
}

void main(void)
{
    PORTA=0x00;		// PORTA初始化
    DDRA=0x0F;
    PORTB=0xFF;		// PORTC初始化
    DDRB=0xFF;

    time[2] = 23; time[1] = 58; time[0] = 55;	// 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;				
		    point_on = ~point_on;			
		    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
    }
}