arrkeyboard_1.c

包括直接式、矩阵式、、中断式键盘接口软件设计和键盘消抖软件设计

/**********************************************
*   File: ArrKeyboard_1.C
*   Description: Array Keyboard Interface Example
*   Created Date:  2007-10-01
*   Last Modified: 2007-10-01
*   Author: Jeffrey - [e-mail]
*   Notes: None
**********************************************/
#include <REGX51.h>

unsigned int Scan_Keyboard();

/**********************************************
*   Function: delay(unsigned int t)
*   Input Variables: t
*   Return Variables: None
*   Usage: Common Delay Routine, t as the delay time ticks
**********************************************/
void delay(unsigned int t)
{
		for(;t>0;t--);		// 延时循环
}

/**********************************************
*   Function: main()
*   Input Variables: None
*   Return Variables: None
*   Usage: Program Entry
*********************************************/

#define ROW_DETECT_1 0xfff0
#define ROW_DETECT_2 0xff0f
#define ROW_DETECT_3 0xf0ff
#define ROW_DETECT_4 0x0fff
#define COLUMN_DETECT_1 0xeeee
#define COLUMN_DETECT_1 0xdddd
#define COLUMN_DETECT_1 0xbbbb
#define COLUMN_DETECT_1 0x7777

void main()
{
		unsigned int Keyboard_Status;										// 按键状态
		unsigned char LED_Status = 0xff;									// 定义键值
		unsigned char Row, Column;
		unsigned char jTemp;												// 临时变量
		unsigned char iTemp;												// 临时变量
		unsigned char BStatus;
		while(1)
		{
			Keyboard_Status = Scan_Keyboard();
			if(~(Keyboard_Status | ROW_DETECT_1))
			{
				Row = 1;												   // 第一行
			}
			else if(~(Keyboard_Status | ROW_DETECT_2))
			{
				Row = 2;												   // 第二行
			}
			else if(~(Keyboard_Status | ROW_DETECT_3))
			{
				Row = 4;												   // 第三行
			}
			else if(~(Keyboard_Status | ROW_DETECT_4))
			{
				Row = 8;												   // 第四行
			}
			
			if(~(Keyboard_Status | COLUMN_DETECT_1))
			{
				Column = 0x10;											   // 第一列
			}
			else if(~(Keyboard_Status | COLUMN_DETECT_2))
			{
				Column = 0x20;											   // 第二列
			}
			else if(~(Keyboard_Status | COLUMN_DETECT_3))
			{
				Column = 0x40;											   // 第三列
			}
			else if(~(Keyboard_Status | COLUMN_DETECT_4))
			{
				Column = 0x80;											   // 第四列
			}
			
			LED_Status = Column + Row;
			P0 = ~LED_Status;
			delay(100);
			// 点亮相应的LED灯				
			//********************主程序部分*********************//
			// Add your code here
			//********************主程序部分*********************//
		}
}
	
/**********************************************
*   Function: Scan_Keyboard
*   Input Variables: None
*   Return Variables: Keys Value
*   Usage: Read Keyboard Status
*********************************************/
unsigned int Scan_Keyboard()
{
		unsigned int Keys_Value;					 // 定义键值变量
		P2 = 0xf7;									 // 第四行置低，准备读取按键状态
		Keys_Value = P2>>4;							 // 读取按键状态
		Keys_Value <<= 4;							 // 移位
		P2 = 0xfb;									 // 第三行置低，准备读取按键状态
		Keys_Value += P2>>4;						 // 读取按键状态
		Keys_Value <<= 4;							 // 移位
		P2 = 0xfd;									 // 第二行置低，准备读取按键状态
		Keys_Value += P2>>4;						 // 读取按键状态
		Keys_Value <<= 4;							 // 移位
		P2 = 0xfe;									 // 第一行置低，准备读取按键状态
		Keys_Value += P2>>4;						 // 读取按键状态		
		return Keys_Value;							 // 返回按键状态值
}