【蓝桥杯单片机笔记3】独立按键&矩阵键盘_p0=0x01<<pos和p0=0x01的区别-优快云博客

本文链接：https://blog.youkuaiyun.com/silver321/article/details/122656411

本文介绍了一种使用51单片机实现独立按键扫描和矩阵键盘读取的方法，并通过HC138译码器控制多位数码管显示。文章详细展示了如何利用延时消抖及状态判断来准确获取按键输入，并将相应的数值显示在数码管上。

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独立按键

题目要求：

代码：

#include "reg52.h"

sbit S7 = P3^0;
sbit S6 = P3^1;
sbit S5 = P3^2;
sbit S4 = P3^3;

sbit L1 = P0^0;
sbit L2 = P0^1;
sbit L3 = P0^2;
sbit L4 = P0^3;
sbit L5 = P0^4;
sbit L6 = P0^5;

void HC138(unsigned char m)
{
	switch(m)
	{
		case 4:P2 = (P2 & 0x1f) | 0x80;break;
		case 5:P2 = (P2 & 0x1f) | 0xa0;break;
		case 6:P2 = (P2 & 0x1f) | 0xc0;break;
		case 7:P2 = (P2 & 0x1f) | 0xe0;break;
	}
}

void DelayK(unsigned char t)
{
	while(t--);
}

unsigned char state = 0;
void ScanKeys()
{
	if(S7 == 0)
	{
		DelayK(100);
		if(S7 == 0)
		{
			if(state == 0)
			{
				L1 = 0;
				state = 1;
			}
			else if(state == 1)
			{
				L1 = 1;
				state = 0;
			}
			while(S7 == 0);
		}
	}
	if(S6 == 0)
	{
		DelayK(100);
		if(S6 == 0)
		{
			if(state == 0)
			{
				L2 = 0;
				state = 2;
			}
			else if(state == 2)
			{
				L2 = 1;
				state = 0;
			}
			while(S6 == 0);
		}
	}
	if(S5 == 0)
	{
		DelayK(100);
		if(S5 == 0)
		{
			if(state == 1)
			{
				L3 = 0;
				while(S5 == 0);
				L3 = 1;
			}
			else if(state == 2)
			{
				L5 = 0;
				while(S5 == 0);
				L5 = 1;
			}
		}
	}
	if(S4 == 0)
	{
		DelayK(100);
		if(S4 == 0)
		{
			if(state == 1)
			{
				L4 = 0;
				while(S4 == 0);
				L4 = 1;
			}
			else if(state == 2)
			{
				L6 = 0;
				while(S4 == 0);
				L6 = 1;
			}
		}
	}
}
void Initsystem()
{
	HC138(5);
	P0=0x00;
	HC138(4);
	P0=0xff;
}

void main()
{
	Initsystem();

	while(1)
	{
		ScanKeys();
	}
}

矩阵键盘

#include "reg52.h"
sfr P4=0xC0;

sbit L1 = P3^4;
sbit L2 = P3^5;
sbit L3 = P4^2;
sbit L4 = P4^4;

sbit R1 = P3^0;
sbit R2 = P3^1;
sbit R3 = P3^2;
sbit R4 = P3^3;

unsigned char code SMG_Duan[] = {0xC0,0xF9,0xA4,0xB0,0x99,
0x92,0x82,0xF8,0x80,0x90,0x88,0x80,0xC6,0xc0,0x86,0x8E,0xBF,0x7F};

void HC138(unsigned char m)
{
	switch(m)
	{
		case 4:P2 = (P2 & 0x1f) | 0x80;break;
		case 5:P2 = (P2 & 0x1f) | 0xa0;break;
		case 6:P2 = (P2 & 0x1f) | 0xc0;break;
		case 7:P2 = (P2 & 0x1f) | 0xe0;break;
	}
}

void SMG_display(unsigned char pos,unsigned char value)
{
 	HC138(6);
	P0=0x01<<pos;
	HC138(7);
	P0=value;
}

unsigned char Key_Num=0;
void ScanKeys()
{
	R1=0;
	R2=R3=R4=1;
	L1=L2=L3=L4=1;
	if(L1==0)
	{
		while(L1==0);
		Key_Num=0;
		SMG_display(0,SMG_Duan[Key_Num]);
	}
	else if(L2==0)
	{
		while(L2==0);
		Key_Num=1;
		SMG_display(1,SMG_Duan[Key_Num]);
	}	
	else if(L3==0)
	{
		while(L3==0);
		Key_Num=2;
		SMG_display(2,SMG_Duan[Key_Num]);
	}
	else if(L4==0)
	{
		while(L4==0)
		Key_Num=3;
		SMG_display(3,SMG_Duan[Key_Num]);
	}
	
	R2=0;
	R1=R3=R4=1;
	L1=L2=L3=L4=1;
	if(L1==0)
	{
		while(L1==0);
		Key_Num=4;
		SMG_display(4,SMG_Duan[Key_Num]);
	}
	else if(L2==0)
	{
		while(L2==0);
		Key_Num=5;
		SMG_display(5,SMG_Duan[Key_Num]);
	}	
	else if(L3==0)
	{
		while(L3==0);
		Key_Num=6;
		SMG_display(6,SMG_Duan[Key_Num]);
	}
	else if(L4==0)
	{
		while(L4==0)
		Key_Num=7;
		SMG_display(7,SMG_Duan[Key_Num]);
	}
	
	R3=0;
	R1=R2=R4=1;
	L1=L2=L3=L4=1;
	if(L1==0)
	{
		while(L1==0);
		Key_Num=8;
		SMG_display(7,SMG_Duan[Key_Num]);
	}
	else if(L2==0)
	{
		while(L2==0);
		Key_Num=9;
		SMG_display(6,SMG_Duan[Key_Num]);
	}	
	else if(L3==0)
	{
		while(L3==0);
		Key_Num=10;
		SMG_display(5,SMG_Duan[Key_Num]);
	}
	else if(L4==0)
	{
		while(L4==0)
		Key_Num=11;
		SMG_display(4,SMG_Duan[Key_Num]);
	}	
	
	R4=0;
	R1=R3=R2=1;
	L1=L2=L3=L4=1;
	if(L1==0)
	{
		while(L1==0);
		Key_Num=12;
		SMG_display(3,SMG_Duan[Key_Num]);
	}
	else if(L2==0)
	{
		while(L2==0);
		Key_Num=13;
		SMG_display(2,SMG_Duan[Key_Num]);
	}	
	else if(L3==0)
	{
		while(L3==0);
		Key_Num=14;
		SMG_display(1,SMG_Duan[Key_Num]);
	}
	else if(L4==0)
	{
		while(L4==0)
		Key_Num=15;
		SMG_display(0,SMG_Duan[Key_Num]);
	}	

}


void Initsystem()
{
	HC138(5);
	P0=0x00;
	HC138(4);
	P0=0xff;
}

void main()
{
	Initsystem();

	while(1)
	{
		ScanKeys();
	}
}