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[on:]

Hi,

I'm trying to use the attachInterrupt() with the ATmega644 for sensing a rotary encoder.
For some reason the uC doesn't catch the interrupt. This is my code

Code:

// Rotary encoder interrupt service routine
boolean rotating=false;
void rotEncoder(){
rotating=true; // If motion is detected in the rotary encoder, set the flag to true
}

void setup(){
        // Attach Interrupts
attachInterrupt(2, rotEncoder, CHANGE);  // ISR for rotary encoder on pin 2

pinMode(4, INPUT);  // Button switch or Encoder pin for volume up
pinMode(2, INPUT);  // Button switch or Encoder pin for volume down
pinMode(3, INPUT);  // Button switch or pin for encoder built-in switch

digitalWrite(2, HIGH); // If H/W debouncing is implemented, set to LOW
digitalWrite(4, HIGH); // If H/W debouncing is implemented, set to LOW
digitalWrite(3, HIGH); // Enable pull-up resistor
}

void loop(){

        if (rotating){
            // do something
        }
}

When I take a look at the Sanguino website it states that the ATmega's interrupt pins are pin 2, 10 & 11. According to the site I should use int 2 to attach the interrupt routine to pin 2.
http://sanguino.cc/useit

Perhaps I'm getting it wrong. Some help is needed here  

[Reply #1 on:]

Interrupt variables need to be volatile, eg.

Code:

volatile boolean rotating=false;

Also your code doesn't actually do anything on the interrupt so how do you know it fails?

http://www.gammon.com.au/interrupts

[Reply #2 on:]

I did not paste the code, because it is quite large. I know it fails because when I use the exact same code on my arduino Uno the interrupt gets fired. I can see the result on a display and I can hear the volume go up or down, so I know it's working on the Uno. I use it to control a DAC btw

For the Uno I use this line:

Code:

attachInterrupt(0, rotEncoder, CHANGE);  // ISR for rotary encoder on pin 2

instead of

Code:

attachInterrupt(2, rotEncoder, CHANGE);  // ISR for rotary encoder on pin 2

.

[Reply #3 on:]

Are you reading digital input pins inside the ISR routines (most quadrature decoder ISR do have to), and you should be adjusting for the different pin mapping of the Sanguino then the Uno ISR routine uses?

What modified IDE version are you using, as the Sanguino folks haven't seemed to have kept up with the arduino IDE versions sense version 18 or so, not that would keep you from still using an older IDE modified to include the Sanguino 644P stuff.

Lefty

[Reply #4 on:]

The have kept up to version 1.01

http://code.google.com/p/sanguino/downloads/list

[Reply #5 on:]

The have kept up to version 1.01

http://code.google.com/p/sanguino/downloads/list

Ah, good to see. So could you at least post your two ISR functions?

Lefty

[Reply #6 on:]

Of course, but they are they same. Assuming that you mean the ISR function that works and the one that doesn't...

This one works (Arduino Uno)

Code:

// Rotary encoder interrupt service routine
volatile boolean rotating=false;

void rotEncoder(){
rotating=true; // If motion is detected in the rotary encoder, set the flag to true
}

This one does not (ATmega644).

Code:

volatile boolean rotating=false;
void rotEncoder()
{
rotating=true; // If motion is detected in the rotary encoder, set the flag to true
}

[Reply #7 on:]

Code:

static volatile rotating=false;

Missing the variable type for that statement?

Lefty

[Reply #8 on:]

Sorry I messed up the code while pasting it. I corrected it. I was hoping that the missing variable type was the problem, but it's not. Messing up the pasted code was clearly a PEBKAC ("Problem Exists Between Keyboard And Chair")  

[Reply #9 on:]

Sorry I messed up the code while pasting it. I corrected it. I was hoping that the missing variable type was the problem, but it's not. Messing up the pasted code was clearly a PEBKAC ("Problem Exists Between Keyboard And Chair")  

While in the Air Force we would have wrote it up as "found short between the headsets". 

Lefty

[Reply #10 on:]

haha.., there are numerous variations to it.

Could it have something to do with the fuses? Mine differ from sanguino's fuses.

[Reply #11 on:]

I'm trying to use the attachInterrupt() with the ATmega644 for sensing a rotary encoder.
For some reason the uC doesn't catch the interrupt. This is my code
...
When I take a look at the Sanguino website it states that the ATmega's interrupt pins are pin 2, 10 & 11. According to the site I should use int 2 to attach the interrupt routine to pin 2.

Do you actually have a Sanguino?

[Reply #12 on:]

Code:

attachInterrupt(2, rotEncoder, CHANGE);  // ISR for rotary encoder on pin 2

INT0 is typically on PD2.

With that corrected, your code works.

[Reply #13 on:]

I'm trying to use the attachInterrupt() with the ATmega644 for sensing a rotary encoder.
For some reason the uC doesn't catch the interrupt. This is my code
...
When I take a look at the Sanguino website it states that the ATmega's interrupt pins are pin 2, 10 & 11. According to the site I should use int 2 to attach the interrupt routine to pin 2.

Do you actually have a Sanguino?

Sorry, been away for a few days...

No I do not have the Sanguino, I was only inspired by it. I designed my own controller that can be mounted piggyback onto any 20x4 HD44780 based display. I use it to control my DAC. Here's al link to my creation. http://ce-designs.net/index.php/my-projects/other-builds/ce644-the-es9018-i2c-controller

Code:

attachInterrupt(2, rotEncoder, CHANGE);  // ISR for rotary encoder on pin 2

INT0 is typically on PD2.

With that corrected, your code works.

So you're saying I should change it to:

Code:

attachInterrupt(0, rotEncoder, CHANGE);  // ISR for rotary encoder on pin 2

???
Already tried that without success.

[Reply #14 on:]

To save me reading all that, can you please state which pin, on the Atmega644 chip, you are attaching the device which is to generate an interrupt?