timer.c~

按键是比较复杂。可以用状态机表示。 每10mS执行一次键盘扫描任务 0、无键

#include "timer.h"
#include <avr/io.h>
#include <avr/interrupt.h>

volatile unsigned char ftimer2ms_ok, ftimer10ms_ok, ftimer1s_ok;
unsigned char timer1s_count;

void timer_init(void)
{
        TCCR0 = (1<<WGM01)|(1<<CS02);   /* CTC, 256分频 */
        TCNT0 = 0;
        OCR0 = (FOSC/N/500-1);          /* 2ms, 500Hz */
        
        /* CTC, 1024分频, 注意分频设置与T/C0不同 */
        TCCR2 = (1<<WGM01)|(1<<CS02)|(1<<CS01)|(1<<CS00);
        TCNT2 = 0;
        OCR2 = (FOSC/1024/100-1);       /* 10ms, 100Hz */
		
		TIMSK = (1<<OCIE0)|(1<<OCIE2);
}

ISR(TIMER0_COMP_vect)
{
        ftimer2ms_ok = 1;
}

ISR(TIMER2_COMP_vect)
{
        ftimer10ms_ok = 1;
        if(++timer1s_count >= 100)
        {
                timer1s_count = 0;
				ftimer1s_ok = 1;
        }
}