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Topic: <SOLVED> ATmega644 does not catch the interupt (Read 3068 times) previous topic - next topic

corprius

Jan 26, 2013, 01:29 am Last Edit: Feb 09, 2013, 11:30 am by corprius Reason: 1
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: [Select]
// 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  :~

Nick Gammon

Interrupt variables need to be volatile, eg.

Code: [Select]

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
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

corprius

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: [Select]
attachInterrupt(0, rotEncoder, CHANGE);  // ISR for rotary encoder on pin 2 instead of
Code: [Select]
attachInterrupt(2, rotEncoder, CHANGE);  // ISR for rotary encoder on pin 2.


retrolefty

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

corprius

The have kept up to version 1.01

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


retrolefty


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

corprius

#6
Jan 26, 2013, 09:06 pm Last Edit: Jan 26, 2013, 09:15 pm by corprius Reason: 1
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: [Select]
// 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: [Select]
volatile boolean rotating=false;
void rotEncoder()
{
rotating=true; // If motion is detected in the rotary encoder, set the flag to true
}


retrolefty

Code: [Select]
static volatile rotating=false;

Missing the variable type for that statement?

Lefty

corprius

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")  :smiley-roll-blue:

retrolefty


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")  :smiley-roll-blue:


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

Lefty

corprius

haha.., there are numerous variations to it.

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


Nick Gammon


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?
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

dhenry

Code: [Select]
attachInterrupt(2, rotEncoder, CHANGE);  // ISR for rotary encoder on pin 2

INT0 is typically on PD2.

With that corrected, your code works.

corprius



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: [Select]
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: [Select]
attachInterrupt(0, rotEncoder, CHANGE);  // ISR for rotary encoder on pin 2???
Already tried that without success.

Nick Gammon

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?
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

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