4X4矩阵键盘扫描程序

4X4矩阵键盘扫描：

1. 4根行线的GIO均设为Output，根列线的GIO均设为Input；

2. 4根行线的GIO分别置为0111、1011、1101、1110，读逐一读取列线GIO的值，可确定是哪一个按键。

电路图例如以下：

注意：

1. 图中用作输入的GIO，一定要有一个上拉电阻。

2. 芯片中的每个引脚是否用作了GPIO口来用。需配置芯片的寄存器，使引脚当作GPIO口来使用，才会有效。

測试代码例如以下：

#define KEY_GIO_ROW_1	37

#define KEY_GIO_ROW_2	33

#define KEY_GIO_ROW_3	32

#define KEY_GIO_ROW_4	35

#define KEY_GIO_COL_1	22

#define KEY_GIO_COL_2	23

#define KEY_GIO_COL_3	24

#define KEY_GIO_COL_4	36

int scanKey()

{

	int keyValue = 0;

	int col1Value=0,col2Value=0,col3Value=0,col4Value=0,row1Value=0,row2Value=0,row3Value=0,row4Value=0;

	static int press1=0,press2=0,press3=0,press4=0;

	static int press5=0,press6=0,press7=0,press8=0;

	static int press9=0,press10=0,press11=0,press12=0;

	static int press13=0,press14=0,press15=0,press16=0;

	dm365SetGPIO(KEY_GIO_ROW_1, 0);

	dm365SetGPIO(KEY_GIO_ROW_2, 1);

	dm365SetGPIO(KEY_GIO_ROW_3, 1);

	dm365SetGPIO(KEY_GIO_ROW_4, 1);

	col1Value = dm365GetGPIO(KEY_GIO_COL_1);

	col2Value = dm365GetGPIO(KEY_GIO_COL_2);

	col3Value = dm365GetGPIO(KEY_GIO_COL_3);

	col4Value = dm365GetGPIO(KEY_GIO_COL_4);

	keyValue = col1Value | (col2Value << 1) | (col3Value << 2) | (col4Value << 3);

//	printf("=1==keyValue = %x\n",keyValue);

	switch(keyValue)

	{

		case 0x0E:

			{

				if(!press1)

				{

					press1 = 1;

					printf("KEY 1\n");

				}

			}

			break;

		case 0x0D:

			{

				if(!press2)

				{

					press2 = 1;

					printf("KEY 2\n");

				}

			}

			break;

		case 0x0B:

			{

				if(!press3)

				{

					press3 = 1;

					printf("KEY 3\n");

				}

			}

			break;

		case 0x07:

			{

				if(!press4)

				{

					press4 = 1;

					printf("KEY 4\n");

				}

			}

			break;

		default:

			{

				press1 = 0;

				press2 = 0;

				press3 = 0;

				press4 = 0;

			}

			break;

	}

	dm365SetGPIO(KEY_GIO_ROW_1, 1);

	dm365SetGPIO(KEY_GIO_ROW_2, 0);

	dm365SetGPIO(KEY_GIO_ROW_3, 1);

	dm365SetGPIO(KEY_GIO_ROW_4, 1);

	col1Value = dm365GetGPIO(KEY_GIO_COL_1);

	col2Value = dm365GetGPIO(KEY_GIO_COL_2);

	col3Value = dm365GetGPIO(KEY_GIO_COL_3);

	col4Value = dm365GetGPIO(KEY_GIO_COL_4);

	keyValue = col1Value | (col2Value << 1) | (col3Value << 2) | (col4Value << 3);

//	printf("=2==keyValue = %x\n",keyValue);

	switch(keyValue)

	{

		case 0x0E:

			{

				if(!press5)

				{

					press5 = 1;

					printf("KEY 5\n");

				}

			}

			break;

		case 0x0D:

			{

				if(!press6)

				{

					press6 = 1;

					printf("KEY 6\n");

				}

			}

			break;

		case 0x0B:

			{

				if(!press7)

				{

					press7 = 1;

					printf("KEY 7\n");

				}

			}

			break;

		case 0x07:

			{

				if(!press8)

				{

					press8 = 1;

					printf("KEY 8\n");

				}

			}

			break;

		default:

			{

				press5 = 0;

				press6 = 0;

				press7 = 0;

				press8 = 0;

			}

			break;

	}

	dm365SetGPIO(KEY_GIO_ROW_1, 1);

	dm365SetGPIO(KEY_GIO_ROW_2, 1);

	dm365SetGPIO(KEY_GIO_ROW_3, 0);

	dm365SetGPIO(KEY_GIO_ROW_4, 1);

	col1Value = dm365GetGPIO(KEY_GIO_COL_1);

	col2Value = dm365GetGPIO(KEY_GIO_COL_2);

	col3Value = dm365GetGPIO(KEY_GIO_COL_3);

	col4Value = dm365GetGPIO(KEY_GIO_COL_4);

	keyValue = col1Value | (col2Value << 1) | (col3Value << 2) | (col4Value << 3);

//	printf("=3==keyValue = %x\n",keyValue);

	switch(keyValue)

	{

		case 0x0E:

			{

				if(!press9)

				{

					press9 = 1;

					printf("KEY 9\n");

				}

			}

			break;

		case 0x0D:

			{

				if(!press10)

				{

					press10 = 1;

					printf("KEY 10\n");

				}

			}

			break;

		case 0x0B:

			{

				if(!press11)

				{

					press11 = 1;

					printf("KEY 11\n");

				}

			}

			break;

		case 0x07:

			{

				if(!press12)

				{

					press12 = 1;

					printf("KEY 12\n");

				}

			}

			break;

		default:

			{

				press9 = 0;

				press10 = 0;

				press11 = 0;

				press12 = 0;

			}

			break;

	}

	dm365SetGPIO(KEY_GIO_ROW_1, 1);

	dm365SetGPIO(KEY_GIO_ROW_2, 1);

	dm365SetGPIO(KEY_GIO_ROW_3, 1);

	dm365SetGPIO(KEY_GIO_ROW_4, 0);

	col1Value = dm365GetGPIO(KEY_GIO_COL_1);

	col2Value = dm365GetGPIO(KEY_GIO_COL_2);

	col3Value = dm365GetGPIO(KEY_GIO_COL_3);

	col4Value = dm365GetGPIO(KEY_GIO_COL_4);

	keyValue = col1Value | (col2Value << 1) | (col3Value << 2) | (col4Value << 3);

//	printf("=4==keyValue = %x\n",keyValue);

	switch(keyValue)

	{

		case 0x0E:

			{

				if(!press13)

				{

					press13 = 1;

					printf("KEY 13\n");

				}

			}

			break;

		case 0x0D:

			{

				if(!press14)

				{

					press14 = 1;

					printf("KEY 14\n");

				}

			}

			break;

		case 0x0B:

			{

				if(!press15)

				{

					press15 = 1;

					printf("KEY 15\n");

				}

			}

			break;

		case 0x07:

			{

				if(!press16)

				{

					press16 = 1;

					printf("KEY 16\n");

				}

			}

			break;

		default:

			{

				press13 = 0;

				press14 = 0;

				press15 = 0;

				press16 = 0;

			}

			break;

	}

	return keyValue;

}

void *KeyMngThread()

{

	int resetValue = 1;

	int resetCout = 0;

	int alarmInValue = 1;

	int alarmInCout = 0;

	while(1)

	{

		resetValue = dm365GetGPIO(GIO_RESET);

		if(0 == resetValue)

		{

			resetCout++;

		}

		else if(1 == resetValue)

		{

			resetCout = 0;

		}

		if(resetCout == 30)

		{

			resetCout = 0;

			system("rm -f /mnt/nand/sysenv.cfg");

			system("/bin/sync");

//			System("reboot");

			system("/tmp/shutdown -r now \n");

		}

		alarmInValue = dm365GetGPIO(GIO_ALARM_IN);

		if(0 == alarmInValue)

		{

			dm365SetGPIO(GIO_LED,0);	//control led off .

		}

		else if(1 == alarmInValue)

		{

			dm365SetGPIO(GIO_LED,1);	//control led on .

		}

		scanKey();

		usleep(100000);

	}

}

代码中dm365SetGPIO( )里将GPIO默认设置为Output，

dm365GetGPIO( )中将GPIO默认设置为Input,

通过字符设备驱动实现应用层操作底层GPIO。

4X4矩阵键盘扫描程序的相关教程结束。