QX----mini51单片机学习---（7）矩阵键盘

目录

1矩阵键盘的识别

2相关c语言

3实践编程

1矩阵键盘的识别

假设按列扫描按下S6P30：0P34：1然后高流向低，P34：0，刚开始是0xf0：1111 0000

后面是0xe0：1110 0000  ，当是0xe0能确定是第一列被按下，再按行扫描，S6：0x0e

综合：0xee

2相关c语言

略

3实践编程

#include<reg52.h>
#include<intrins.h>

#define uint unsigned int 
#define uchar unsigned char
	
sbit DU = P2^6;
sbit WE = P2^7;

uchar num;//数码管的值
uchar KeyValue = 20;//按键值,初始值是-
//code固定table的值,code很大8k,ram区小
//共阴数码管段选值
uchar code table[] = {0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,
0x77,0x7c,0x39,0x5e,0x79,0x71,0x76,0x38,0x37,0x3e,0x40,0x00};
void delay(unsigned int xms)		//@12.000MHz
{
	unsigned char i, j;
	while(xms--)
	{
		i = 2;
	j = 239;
	do
	{
		while (--j);
	} while (--i);
	}
}

void KeyScan()
{
	//4*4
	//列扫描
	P3=0xf0;
	if(P3!=0xf0)
	{
		//消抖
			delay(10);
			if(P3!=0)
			{
				switch(P3)//判断哪一列
			{
				case 0xe0: KeyValue = 0; break;
				case 0xd0: KeyValue = 1; break;
				case 0xb0: KeyValue = 2; break;
				case 0x70: KeyValue = 3; break;
					
			}
			//行扫描
			P3=0x0f;
			switch(P3)//判断哪一行
			{
				case 0x0e: KeyValue = KeyValue; break;
				case 0x0d: KeyValue = KeyValue + 4; break;
				case 0x0b: KeyValue = KeyValue + 8; break;
				case 0x07: KeyValue = KeyValue + 12; break;
					
			}
			//松手（当我们松手后，电流无法流到地，通过上拉电阻回到初始状态
			while(P3 != 0x0f);
			}
			//独立按键
			P3=0xff;
			if(P3!=0xff)
			{
				delay(10);
				if(P3!=0xff)
				{
					switch(P3)//判断哪一行
			{
				case 0xfe: KeyValue = 16; break;
				case 0xfd: KeyValue = 17; break;
				case 0xfb: KeyValue = 18; break;
				case 0xf7: KeyValue = 19; break;
					
			}
			//松手（当我们松手后，电流无法流到地，通过上拉电阻回到初始状态
			while(P3 != 0xff);
			}
				
				}
			}
			
	}
	
	
}
void main()
{
	WE = 1;
	P0=0xfb;//位选给0
	WE = 0;//锁存器锁存
	while(1)
	{
		KeyScan();
			DU = 1;
			P0 = table[KeyValue];//0000 0110 共阴极给1亮
			DU = 0;
  }
}