main_key.c

WINAVR写的2x8键盘扫描程序

/*
File name:main_key.c 
Function: 利用定时器定时中断来扫描键盘，并把键值显示到LCM1602上
Author:ken
Date:2007-08-15
*/

#include <avr/io.h>
#include "2X8_key.h"
#include "lcm1602.h"
#include <util/delay.h>
//#include <inttypes.h>
#include <avr/interrupt.h>
#include "type.h"

/* 
 * Name:Timer0_init
 * Function:定时器0初始化，定时21ms
 * In:null
 * Out:null
 * Author:Ken
 * Date:2007-08-15
*/
void Timer0_init(void)
{
 TCNT0 = 0x1A; //set count
 OCR0  = 0xE6;  //set compare
 TCCR0|= ((1<<CS02)|(1<<CS00));  //1024预分频 0x05
 TIMSK|= (1<<TOIE0);               //允许TC0溢出中断
}

SIGNAL(SIG_OVERFLOW0)
{
  TCNT0 = 0x1A;  //set count
	key();
}

int main(void)
{
  key_init();
	Timer0_init();
	LCM1602Init();
	sei();
	while(1)
	{
	  unsigned char temp_key1;
		temp_key1=key();
		_delay_ms(50);
		if(temp_key1==key())
		{
		  //LCM1602Write_String(0,0,temp_key1);
			LCM1602Write_number(temp_key1);
		}
	}
}