Atmega 328 Pin 11 Pin Change interrupt

Projects Programming
1

Hi everyone!

I've been reading over this thread http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1259918394/15 on how to implement a 3rd "software" interrupt,

I am attempting to do the same thing on my Uno using Pin 11 - I have read through the data sheet specifically chapters 11 and 12 and have come up with the following code:

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


void setup() {
  pinMode(11, INPUT);
  Serial.begin(9600);

PCICR |= (1 << PCIE1);
PCMSK1 |= (1 << PCINT11);

}

volatile int print_flag = 0;

ISR(PCINT2_vect)
{
  print_flag = 3;
}

ISR(PCINT0_vect)
{
  print_flag = 1;
}

ISR(PCINT1_vect)
{
  print_flag = 2;
}

void loop()
{
  if(print_flag == 1)
  {
    Serial.println("interrupt on pcint 0");
    print_flag = 0;
  }
  else if (print_flag == 2)
  {
    Serial.println("interrupt on pcint 1");
    print_flag = 0;
   }
   else if (print_flag == 3)
   {
     Serial.println("interrupt on pcint 2");
      print_flag = 0;
   }
}

As far as I can tell from the data sheet this is correct though it doesn't appear to be working,

I tried the Pin 5 example and it works perfectly - any pointers in the right direction would be much appreciated

Thanks,

Dave

2

I solved my own problem - got mixed up between Pin Numbers and the actual pin mapping :blush:

Here is the correct code:

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


void setup() {
  pinMode(11, INPUT);
  Serial.begin(9600);

PCICR |= (1 << PCIE0);
PCMSK0 |= (1 << PCINT3);

}

volatile int print_flag = 0;

ISR(PCINT2_vect)
{
  print_flag = 3;
}

ISR(PCINT0_vect)
{
  print_flag = 1;
}

ISR(PCINT1_vect)
{
  print_flag = 2;
}

void loop()
{
  if(print_flag == 1)
  {
    Serial.println("interrupt on pcint 0");
    print_flag = 0;
  }
  else if (print_flag == 2)
  {
    Serial.println("interrupt on pcint 1");
    print_flag = 0;
   }
   else if (print_flag == 3)
   {
     Serial.println("interrupt on pcint 2");
      print_flag = 0;
   }
}
3

I'm assuming to detach the interrupt I would simple change this:

PCICR |= (1 << PCIE0);
PCMSK0 |= (1 << PCINT3);

to this:

PCICR |= (0 << PCIE0);
PCMSK0 |= (0 << PCINT3);

Yes?

Cheers,

Dave