key: 一个精简但功能强大的按键驱动

1. 介绍

2. 原理介绍

2.1 键值码

 短按键值码 = 键值码
 shift键值码 = shift键值码 | 键值码.
 长按键值码 = ~键值码

3.算法说明

//PreKey:前次按键值
//NowKey:当前按键值
//PreScanKey:前次采样值 
//NowReadKey:当前采样值 
 a.按键获取算法
 1).NowKey & PreKey : 电平触发 
 2).NowKey ^ PreKey : 边缘触发 
 3).NowKey & (NowKey ^ PreKey)或(~PreKey) & NowKey : 上升沿触发
 4).PreKey & (NowKey ^ PreKey)或PreKey & (~NowKey) : 下降沿触发
 b.滤波算法
 1).PreScanKey & NowScanKey : 电平触发
 2).PreReadKey & (PreScanKey ^ NowScanKey) : 采样保持
 3).NowReadKey = 1) | 2) : 带采样保持的电平触发
//以上算法可通过列真值表推导

4.功能说明

5. 移植说明

typedef enum
{
 //短按键键值码
 KEY_UP = 0x0001,
 KEY_DN = 0x0002,
 KEY_LT = 0x0004,
 KEY_RT = 0x0008, 
 KEY_ENT = 0x0010,
 KEY_ESC = 0x0020,
 KEY_INC = 0x0040,
 KEY_DEC = 0x0080,
 KEY_FUN = 0x0100,
 //长按键键值码
 KEY_UP_L 	 = 0xFFFE,	
 KEY_DN_L 	 = 0xFFFD,
 //shift按键键值码
 KEY_UP_SF = 0x0101,
 KEY_DN_SF = 0x0102,
 KEY_LT_SF = 0x0104,
 KEY_RT_SF = 0x0108, 
 KEY_ENT_SF = 0x0110,
 KEY_ESC_SF = 0x0120,
 KEY_INC_SF = 0x0140,
 KEY_DEC_SF = 0x0180
} KEY_value;

__weak static KEY_TYPE KeyIOread( void )
{
 KEY_TYPE KeyScanCode=0;
 
	KeyScanCode |= GPIO_IN(K_UP ) ? 0 : KEY_UP ;
	KeyScanCode |= GPIO_IN(K_DN ) ? 0 : KEY_DN ;
	KeyScanCode |= GPIO_IN(K_LT ) ? 0 : KEY_LT ;
	KeyScanCode |= GPIO_IN(K_RT ) ? 0 : KEY_RT ;
	KeyScanCode |= GPIO_IN(K_ENT) ? 0 : KEY_ENT;
	KeyScanCode |= GPIO_IN(K_ESC) ? 0 : KEY_ESC;
	KeyScanCode |= GPIO_IN(K_INC) ? 0 : KEY_INC;
	KeyScanCode |= GPIO_IN(K_DEC) ? 0 : KEY_DEC;
	KeyScanCode |= GPIO_IN(K_FUN) ? 0 : KEY_FUN;
	
 return KeyScanCode;
}

6. 使用说明

void KeyTest(void)
{
	while(1)
	{
		
		KeyScan();
		delay_ms(20);
		KeyScan();
			switch(KeyGet())
			{
				case KEY_UP : printf("Key Read : UP \r\n");break;
				case KEY_DN : printf("Key Read : DN \r\n");break;			
				case KEY_LT : printf("Key Read : LT \r\n");break;	
				case KEY_RT : printf("Key Read : RT \r\n");break;
				case KEY_ENT: printf("Key Read : ENT\r\n");break;			
				case KEY_ESC: printf("Key Read : ESC\r\n");break;	
				case KEY_INC: printf("Key Read : INC\r\n");break;
				case KEY_DEC: printf("Key Read : DEC\r\n");break;			
				case KEY_FUN: printf("Key Read : FUN\r\n");break;
				case KEY_UP_L : printf("Key Read : UP for long key \r\n");break;
				case KEY_DN_L : printf("Key Read : DN for long key \r\n");break;	
				case KEY_UP_SF : printf("Key Read : UP with shift key \r\n");break;
				case KEY_DN_SF : printf("Key Read : DN with shift key \r\n");break;			
				case KEY_LT_SF : printf("Key Read : LT with shift key \r\n");break;	
				case KEY_RT_SF : printf("Key Read : RT with shift key \r\n");break;
				case KEY_ENT_SF: printf("Key Read : ENT with shift key \r\n");break;			
				case KEY_ESC_SF: printf("Key Read : ESC with shift key \r\n");break;	
				case KEY_INC_SF: printf("Key Read : INC with shift key \r\n");break;
				case KEY_DEC_SF: printf("Key Read : DEC with shift key \r\n");break;			
				default :	break;		
			}
	}	
	
}

8. 更新说明