Help on Atmega48 (LED toggle using a single key )

[srbombaywala]

Hi there,
I decided to toggle the leds by using PCINT interrupts.
but now the problem is that as i use a swtich it interrupts twice. Once when the key is pressed and other when released and so the toggle become two times on one press.
I included a condition in the ISR but nothing seems to work.
what i want is that if the key is kept pressed; nothing should happen and the led's should not toggle unless its released.
the code is as below

#include <avr/io.h>
#include <avr/interrupt.h>

#include <util/delay.h>

#define SETBIT(ADDRESS,BIT) (ADDRESS |= (1<<BIT))
#define CLEARBIT(ADDRESS,BIT) (ADDRESS &= ~(1<<BIT))
#define FLIPBIT(ADDRESS,BIT) (ADDRESS ^= (1<<BIT))
#define CHECKBIT(ADDRESS,BIT) (ADDRESS & (1<<BIT))
#define WRITEBIT(RADDRESS,RBIT,WADDRESS,WBIT) (CHECKBIT(RADDRESS,RBIT) ? SETBIT(WADDRESS,WBIT) : CLEARBIT(WADDRESS,WBIT))
volatile int i=0;
int main(void)
{ 
DDRB &= ~(1 << DDB0); // Clear the PB0 pin
// PB0 (PCINT0 pin) is now an input

PORTB |= (1 << PORTB0); // turn On the Pull-up
// PB0 is now an input with pull-up enabled
DDRD = 0xFF;
PORTD = 0xF9;

PCICR |= (1 << PCIE0); // set PCIE0 to enable PCMSK0 scan
PCMSK0 |= (1 << PCINT0); // set PCINT0 to trigger an interrupt on state change 

sei(); // turn on interrupts

while(1)
        {

            if(i==3)
           {
             i=0;
             SETBIT(PORTD,0);
             CLEARBIT(PORTD,1);
            CLEARBIT(PORTD,2);
           }
          else
          if(i==1)
          {
           SETBIT(PORTD,1);
           CLEARBIT(PORTD,2);
           CLEARBIT(PORTD,0);
          }
         else
         {
          SETBIT(PORTD,2);
          CLEARBIT(PORTD,0);
          CLEARBIT(PORTD,1);
          }
       }

}


ISR (PCINT0_vect)
{

     if(PORTB & (1 << PB0))
    {
      i++;
     }
    else
    {
      i=i;
     }


}

I wont be using int0 and int1 level triggers as they are needed to be used for other functions.

Kindly help.

 

[alexan_e]

You interrupt fires when it is pressed or depressed but you only use the depress action so this is fine.
The problem is probably the button bounce, a single push can give several on/off pulses before it stabilizes, have you use a denounce circuit externally?

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