matrix_key.c

C51操作5767收音机芯片(内置杭州的几个台)

#include "Matrix_Key.h"
/*
 * 矩阵键盘通用程序(引脚输入输出方向不切换)
 */

//KEY_PINS 低4位为ROW(监听) 高4位为COL(输出,低电平)
//	7	6	5	4	3	2	1	0    
// Co4 Co3 Co2 Co1 Ro4 Ro3 Ro2 Ro1

/*	COL 4 3 2 1
	ROW	4
		3
		2
		1
*/

unsigned char row=0,col=0;


//<返回其列号(col) 需要事先准备其行号掩码>
static unsigned char Matrix_Key_Scan_Col(const unsigned char rowbitmask)
{
	unsigned char i=0;
	unsigned char colmask;
	KEY_PINS = 0x0f;
	colmask=0x0f;
	while ( (KEY_PINS & rowbitmask)==0)
	{
		colmask = colmask<<1;
		KEY_PINS = colmask | 0x0f;
		i++;
	}
	return i;
}


//<检测是否有按键按下,并返回其行号(row)>
static unsigned char Matrix_Key_Scan_Row()
{
	KEY_PINS = 0x0f;
	
	if (ROW1 == 0)
	{
		return 1;
	}
	else if (ROW2 == 0)
	{
		return 2;
	}
	else if (ROW3 == 0)
	{
		return 3;
	}
	else if (ROW4 == 0)
	{
		return 4;
	}
	return 0;
}

unsigned char Matrix_Key_Detect()	//行/列
{
	static unsigned char keep_time;
	static unsigned char keep_row;
	static unsigned char keep_col;
	static unsigned char state		= 0;
	unsigned char uScanReturn;

	switch (state)
	{
		case 0:	//检测是否有按钮按下
			if (Matrix_Key_Scan_Row() != 0 )
			{	//<初始化>
				keep_time	= 0;
				keep_row	= 0;
				keep_col	= 0;
				state++;
			}
			break;
		case 1:
			uScanReturn = Matrix_Key_Scan_Row();
			if (uScanReturn != 0 )	//按键按下姿态
			{
				if (keep_time<250) keep_time++;
				if (keep_row == 0) 
				{
					keep_row = uScanReturn;
				}
				if (keep_row != 0 && keep_col == 0)
				{
					keep_col = Matrix_Key_Scan_Col( 0x01<<(keep_row-1) );
				}
			}
			else					//按键松起姿态
			{
				if (keep_time>5)	//检测到有效按键
				{
					keep_time = 0;
					state++;
				}
				else				//按键无效
				{
					state = 0;
				}
			}
			break;
		case 2:
			if (Matrix_Key_Scan_Row() == 0 )		//按键松起姿态(保持)
			{
				if (keep_time<250) keep_time++;
				if (keep_time>5)	//检测到有效松起
				{
					/* 返回信息：检测到有效按键，并可以执行对应操作 */
					state = 0;
					row = keep_row;
					col = keep_col;
					return 1;
				}
			}
			else	//按键被重新按下
			{
					keep_time=0;	//重新计时
			}
			break;
	}
	return 0;

}