学习单片机第4天

//下面是矩阵按键，采用 行列扫描方法，结果显示在静态数码管
#include"reg52.h"
#define GPIO_DIG P1
#define GPIO_KEY P0

unsigned char smgduan[16]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,
0x7c,0x39,0x5e,0x79,0x71};//
char keyvalue;

void delay_ms(int n)
	{
	unsigned int i=0,j=0;
	for(i=0;i<n;i++)
	for(j=0;j<123;j++);
}

void keypros(){
	char a=0;
	//check which column
	GPIO_KEY=0x0f;
	if(GPIO_KEY!=0x0f){
		delay_ms(10);
		if(GPIO_KEY!=0x0f){
			switch(GPIO_KEY){
				case(0x07): keyvalue=0;break;
				case(0x0b): keyvalue=1;break;
				case(0x0d): keyvalue=2;break;
				case(0x0e): keyvalue=3;break;
			}
			
			//check which row 
			GPIO_KEY=0xf0;
			if(GPIO_KEY!=0xf0){
				delay_ms(10);
				if(GPIO_KEY!=0xf0){
					switch(GPIO_KEY){
						case(0x70): keyvalue=keyvalue;break;
						case(0xb0): keyvalue=keyvalue+4;break;
						case(0xd0): keyvalue=keyvalue+8;break;
						case(0xe0): keyvalue=keyvalue+12;break;
					}
					while((a<50)&&(GPIO_KEY!=0xf0)){
						delay_ms(10);
						a++;
					}
				}
			}
		}
	}
	
	
}
void main(){

	while(1){
		keypros();
		GPIO_DIG=~smgduan[keyvalue];
		
					
	}
}