状态机按键-非常好的软件去抖程序

#include "key.h" #define key_state_0 0 //按键的初始状态 #define key_state_1 1 //按键按下的状态 #define key_state_2 2 //按键长按的状态 #define key_state_3 3 //按键释放的状态 #define KEY_NUM 5 static unsigned char keyStates[KEY_NUM]; unsigned char readKey(unsigned char keyNumber) { unsigned int *keyState = &keyStates[keyNumber-1]; unsigned int keyPress; //按键是否被按下 unsigned int keyReturn = 0; //按键返回值 unsigned int flag=0; switch(keyNumber) { case 1: keyPress = KEY1; // 读按键I/O电 break; case 2: keyPress = KEY2; break; case 3: keyPress = KEY3; break; case 4: keyPress = KEY4; break; case 5: keyPress = KEY5; break; } switch (*keyState) { case key_state_0: // 按键初始态 if (!keyPress) { *keyState = key_state_1;// 键被按下，状态转换到键确认态 } break; case key_state_1: // 按键确认态 if (!keyPress) { keyReturn = 1; // 按键仍按下，按键确认输出为“1” *keyState = key_state_2;// 状态转换到键释放态 } else { *keyState = key_state_0; // 按键已抬起，转换到按键初始态 } break; case key_state_2: if (keyPress) { *keyState = key_state_0;//按键已释放，转换到按键初始态 } else { flag++; if(flag>=100) { keyReturn = 2; *keyState = key_state_3;//按键已长按，转换到按键释放态 } } break; case key_state_3: if (keyPress) { *keyState = key_state_0;//按键已释放，转换到按键初始态 } else { keyReturn = 2; } break; } return keyReturn; //返回按键值 } void KeyInit() { unsigned int i; for(i=0;i<KEY_NUM;i++) { keyStates[i] = key_state_0; } } int KeyScan() { unsigned int key=0; if(readKey(1) == 1) //按键返回值是1,第一个键按下 { key=1; } else if(readKey(2) == 1) //按键返回值是1，第二个键按下 { key=2; } else if(readKey(3) == 1) //按键返回值是1，第三个键按下 { key=3; } else if(readKey(4) == 1) //按键返回值是1，第四个键按下 { key=4; } else if(readKey(5) == 1) //按键返回值是1，第五个键按下 { key=5; } else if(readKey(2) == 2) //按键返回值是2，第二个键长按（+） { key=6; } else if(readKey(3) == 2) //按键返回值是2，第三个键长按（-） { key=7; } return key; //以上都不满足则返回0，什么都没按下 }