C51键盘检测相关问题总结

ゝ一世哀愁。 2022-01-30 15:04 204阅读 0赞

**附注：**  
原理图各接口连接关系可参考代码中的端口定义；  
P0口数据锁存器为两片74HC573芯片；  
**1.对独立键盘的检测**

/*--------------------------
    功能：用数码管实现60s计时器
    上电时，数码管显示00
    key4控制开始/暂停计时
    暂停状态下，key1进行加1操作
    key2进行减1操作
    key3进行清零操作
    ---------------------------
    Author: Zhang Kaizhou
    Date: 2019-5-19 19:14:20
    --------------------------*/
    #include <reg52.h>
    #define uchar unsigned char
    #define uint unsigned int
    	
    sbit key1 = P3^4;
    sbit key2 = P3^5;
    sbit key3 = P3^6;
    sbit key4 = P3^7;
    sbit wei_address = P2^7;
    sbit duan_address = P2^6;
    uchar code table[] = {0x3f, 0x06, 0x5b, 0x4f,
    					  0x66, 0x6d, 0x7d, 0x07,
    				      0x7f, 0x6f, 0x77, 0x7c,
    				      0x39, 0x5e, 0x79, 0x71}; // 定义一个无符号字符型数组table[]，存放在单片机内部的ROM或Flash中
    
    uchar n1 = 0, n2 = 0;							
    	
    void init();
    void display(uchar num);
    void keyScan();	
    void delay(uchar xms);											
    											
    void main()
    {
    	init();
    	while(1)
    	{
    		keyScan();
    		display(n1);
    	}
    }
    
    /*初始化函数*/
    void init()
    {
    	TMOD = 0x01; // 定时器0，方式1
    	TH0 = (65536 - 45872) / 256; // 定时50ms
    	TL0 = (65536 - 45872) % 256;
    	EA = 1; // 开全局中断
    	ET0 = 1; // 开定时器0溢出中断
    }
    
    /*定时器0中断服务程序*/
    void T0_interrupt() interrupt 1
    {
    	TH0 = (65536 - 45872) / 256; // 定时器0重装初值
    	TL0 = (65536 - 45872) % 256;
    	n2++;
    	if(n2 == 20) // 定时到1s
    	{
    		n2 = 0;
    		n1++;
    		if(n1 == 60)
    		{
    			n1 = 0;
    		}
    	}
    }
    
    /*数码管显示函数*/
    void display(uchar num)
    {
    	uchar shi, ge;
    	shi = num / 10;
    	ge = num % 10;
    	
    	duan_address = 1; // 在数码管上显示十位的数字
    	P0 = table[shi];
    	duan_address = 0;
    	P0 = 0xff;
    	wei_address = 1;
    	P0 = 0xfe;
    	wei_address = 0;
    	delay(5);
    	
    	duan_address = 1; // 在数码管上显示个位的数字
    	P0 = table[ge];
    	duan_address = 0;
    	P0 = 0xff;
    	wei_address = 1;
    	P0 = 0xfd;
    	wei_address = 0;
    	delay(5);
    }
    
    /*键盘扫描函数*/
    void keyScan()
    {
    	if(!key1) // key1按下，加1
    	{
    		delay(10);
    		if(!key1) 
    		{
    			n1++;
    			if(n1 == 60)
    			{
    				n1 = 0;
    			}
    			while(!key1);
    		}
    	}
    	
    	if(!key2) // key2按下，减1
    	{
    		delay(10);
    		if(!key2) 
    		{
    			if(!n1)
    			{
    				n1 = 60;				
    			}
    			n1--;
    			while(!key2);
    		}
    	}
    	
    	if(!key3) // key4按下，暂停或开始定时器0
    	{
    		delay(10);
    		if(!key3) 
    		{
    			n1 = 0;
    			while(!key3);
    		}
    	}
    	
    	if(!key4)
    	{
    		delay(10);
    		if(!key4)
    		{
    			while(!key4);
    			TR0 = ~TR0;
    		}
    	}
    }
    
    /*延时函数*/
    void delay(uchar xms)
    {
    	uchar i, j;
    	for(i = 0; i < xms; i++)
    		for(j = 0; j < 110; j++);
    }

**2.对矩阵键盘进行扫描**

/*------------------------
    功能：扫描4x4矩阵键盘
    Author: Zhang Kaizhou
    Date: 2019-5-21 21:37:31
    -------------------------*/
    #include <reg52.h>
    #define uchar unsigned char
    	
    sbit wei_address = P2^7;
    sbit duan_address = P2^6;
    
    uchar code table[] = {0x3f, 0x06, 0x5b, 0x4f,
    					  0x66, 0x6d, 0x7d, 0x07,
      				      0x7f, 0x6f, 0x77, 0x7c,
    					  0x39, 0x5e, 0x79, 0x71}; // 定义一个无符号字符型数组table[]，存放在单片机内部的ROM或Flash中
    
    uchar buffer, key;											
    	
    void init_digitron();											
    void array_scan_oneline(uchar address);											
    void array_scan();	
    void display(uchar key);											
    void delay(uchar xms);											
    											
    void main()
    {
    	init_digitron(); // 初始化数码管
    	while(1) // 循环逐行扫描按键是否按下
    	{
    		array_scan();
    	}
    }
    
    /*数码管初始化函数*/
    void init_digitron()
    {
    	P0 = 0; // 关闭所有数码管
    	duan_address = 1;
    	duan_address = 0;
    	
    	P0 = 0x00; // 选中所有数码管
    	wei_address = 1;
    	wei_address = 0;
    }
    
    /*矩阵键盘扫描函数*/
    void array_scan()
    {
    	array_scan_oneline(0xfe);
    	array_scan_oneline(0xfd);
    	array_scan_oneline(0xfb);
    	array_scan_oneline(0xf7);
    }
    
    /*矩阵键盘扫描一行的函数*/
    void array_scan_oneline(uchar address)
    {
    	P3 = address;
    	buffer = P3;
    	buffer = buffer & 0xf0;
    	if(buffer != 0xf0) // 有键按下
    	{
    		delay(10); // 消抖
    		buffer = P3;
    		buffer = buffer & 0xf0;
    		if(buffer != 0xf0)
    		{
    			buffer = P3;
    			switch(buffer)
    			{
    				case 0xee: key = 0; break;
    				case 0xde: key = 1; break;
    				case 0xbe: key = 2; break;
    				case 0x7e: key = 3; break;
    				
    				case 0xed: key = 4; break;
    				case 0xdd: key = 5; break;
    				case 0xbd: key = 6; break;
    				case 0x7d: key = 7; break;
    				
    				case 0xeb: key = 8; break;
    				case 0xdb: key = 9; break;
    				case 0xbb: key = 10; break;
    				case 0x7b: key = 11; break;
    				
    				case 0xe7: key = 12; break;
    				case 0xd7: key = 13; break;
    				case 0xb7: key = 14; break;
    				case 0x77: key = 15; break;
    			}
    			while(buffer != 0xf0) // 等待按键释放
    			{
    				buffer = P3;
    				buffer = buffer & 0xf0;
    			}
    			display(key);
    		}
    	}
    }
    
    /*延时函数*/
    void delay(uchar xms)
    {
    	uchar i, j;
    	for(i = 0; i < xms; i++)
    		for(j = 0; j < 110; j++);
    }
    
    /*数码管显示函数*/
    void display(uchar key)
    {
    	P0 = table[key];
    	duan_address = 1;
    	duan_address = 0;
    }