key.c

用AVR M8控制PT2134音频芯片的程序,显示是LCM2402,还带有有红外遥控功能.

#include<avr/interrupt.h>
#include<avr/io.h>
#include"avr/delay.h"
#include"KEY.h"
//--------------------------------------------------------------------------------

uchar key(void)
{ 
     unsigned char num,key_num;

	 key_num=PINC;    
	 if((key_num|0xf0)!=0xff)
	   {
		 _delay_ms(6);
		 key_num=PINC;
		 if((key_num|0xf0)!=0xff)
		  {
		    cli();
		    key_num|=0xf0;
		    num=key_num;
            // for(PORTC|=0x0f;key_num!=0xff;PORTC|=0x0f,key_num=PINC,key_num|=0xf0);//键值释放判断 
		    for(PORTC|=0x0f;key_num!=0xff;PORTC|=0x0f,key_num=PINC,key_num|=0xf7);//键值释放判断
		    if((num&0x0f)==0x07)num=8;
		    if((num&0x0f)==0x0b)num=9;
		    if((num&0x0f)==0x0d)num=10;
		    if((num&0x0f)==0x0e)num=11;
			sei();
		    _delay_ms(130);
			return num;
		   }
		  
		}
      else return 0;
}