Key.h

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/*
 * Key.h
 *
 * Created: 25.11.2012 20:54:52
 *  Author: Robert
 */ 

#include <stdint.h>
#include <stdbool.h>
#include <avr/io.h>

#ifndef KEY_H_
#define KEY_H_

extern volatile uint8_t kflags;
static const uint8_t KFLAG_KEYPRESSED=1;    
static const uint8_t KFLAG_KEYRELEASED=2;   
static const uint8_t KFLAG_KEYPRESSEDSHORT=4;   
static const uint8_t KFLAG_KEYPRESSEDLONG=8;    

static inline bool  GetKeyState(void)
{
    return !(PINB&0x01);
}


static inline void  KeyInt(void)    
{
    static bool lastKeyState=false; // Key state at last interrupt
    static  uint8_t keyPressedTime=0;   // Counts the time the key is pressed
    static  uint8_t cnt100ms=0; // Counts the 100ms-intervals
    bool    keyState;   // current key state
    
    cnt100ms++;
    if (cnt100ms>=10)
    {
        cnt100ms=0;
    } else
    {
        return;
    }
    // The following is executed every 100ms!
    keyState=GetKeyState();
    if (lastKeyState!=keyState) // Something has changed
    {
        lastKeyState=keyState;  // Keep the key state for next interrupt
        if (keyState)   // Key has just been pressed
        {
            kflags|=KFLAG_KEYPRESSED;
            keyPressedTime=0;
            return;
        } else  // Key has just been released
        {
            kflags|=KFLAG_KEYRELEASED;
            if (keyPressedTime<25)
            {
                kflags|=KFLAG_KEYPRESSEDSHORT;
            }
        }
    }
    if (keyState) {
        if (keyPressedTime<255)
        {
            keyPressedTime++;
        }
        if (keyPressedTime==25) // More than 2.5 seconds
        {
            kflags|=KFLAG_KEYPRESSEDLONG;
        }
    }   
}

#endif /* KEY_H_ */