AST-CAN485 interrupt not working

Development Boards Other Microcontrollers
1

Just working on my AST CAN485 board. The interrupt does not work . Have simple code . Just cannot get the led to blink , it’s Led is On . Nothing happen when I ground the pin 9. Have tried pin 6,7 & 8 still no action.

int MyPin = 9 ;

int Led =13;

volatile int State = LOW;

void setup() {

pinMode(Led, OUTPUT);

attachInterrupt(digitalPinToInterrupt(MyPin), Blink, CHANGE);

}

void loop() {

digitalWrite(Led, State); // turn the LED on (HIGH is the voltage level)

}

void Blink () {

State = !State;

}

Please help

2

Have you tried other modes than just “CHANGE”?

3

Yes just did that , still the same no action ##

4

What’s the external trigger circuit?

5

Switch to Ground.

6

Unless you have an external pullup, you need to turn on pullups on your input pin (otherwise, it will stay low or at least vary between 0 when grounded and possibly 1 depending on noise picked up by the lead). Try adding

pinMode(MyPin, INPUT_PULLUP);

to your setup() before the attachInteruppt()

/mike

7

Hi Mike, just did that added pinMode(MyPin,INPUT_PULLUP);

above attachInterrupt(digitalPinToInterrupt(MyPin), Blink, CHANGE);

Still the same.

I have just check the switch and led on another blink program it works fine.

Devan

8

Asked same question on Amtel forum

https://www.avrfreaks.net/forum/ast-can … ot-working

Believe the interrupt is not enable. Can any one help

9

Could you update your sketch to open the serial port and display the value of EXTERNAL_NUM_INTERRUPTS and let me know the result? I’ve got an idea, but I don’t have one of these boards to test the theory myself.

10

Note that in order to accomplish the request in my previous post, you’ll need to include wiring_private.h so that that macro will be defined in local scope.

11

Ok, I did some experimenting this afternoon and I think I know what your issue is. The AST-CAN485 uses an AT90CAN128 processor, so when compiling your sketch the macro AVR_AT90CAN128 gets defined. Unfortunately, when wiring_private.h gets included, this causes EXTERNAL_NUM_INTERRUPTS to be defined as 2 instead of 8 as expected. In the function attachInterrupt() a check is made so ensure that the interrupt number argument passed in is less than EXTERNAL_NUM_INTERRUPTS. If it is then the interrupt is enabled and the callback function is stored so it can be called when the interrupt occurs. In your case, the interrupt number is 7 since you’re trying to use pin 9, but since EXTERNAL_NUM_INTERRUPTS is being incorrectly defined as 2, the interrupt never gets enabled. To solve the issue, add AVR_AT90CAN128 as an additional check for defining EXTERNAL_NUM_INTERRUPTS as 8 in wiring_private.h (see code below).

#if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__) || defined(__AVR_ATmega128RFA1__) || defined(__AVR_ATmega256RFR2__) || \
    defined(__AVR_AT90USB82__) || defined(__AVR_AT90USB162__) || defined(__AVR_ATmega32U2__) || defined(__AVR_ATmega16U2__) || defined(__AVR_ATmega8U2__) || defined(__AVR_AT90CAN128__)
    #define EXTERNAL_NUM_INTERRUPTS 8
#elif defined(__AVR_ATmega1284__) || defined(__AVR_ATmega1284P__) || defined(__AVR_ATmega644__) || defined(__AVR_ATmega644A__) || defined(__AVR_ATmega644P__) || defined(__AVR_ATmega644PA__)
    #define EXTERNAL_NUM_INTERRUPTS 3
#elif defined(__AVR_ATmega32U4__)
    #define EXTERNAL_NUM_INTERRUPTS 5
#else
    #define EXTERNAL_NUM_INTERRUPTS 2
#endif
12

Hi M,

Being a intermediate coder. I am trying to understand what you saying. Where do I find wiring_private.h.

And you want me to add:-

#elif defined(AVR_AT90CAN128 )

#define EXTERNAL_NUM_INTERRUPTS 8

13

Hi M,

Did find the a wiring_private.h file. sitting Arduino-hardware but in the Documents\Arduino\hardware\LeoStickBoardProfile-master. Not for AST-CAN485. But include the statement (AVR_AT90CAN128 )

#if defined(AVR_ATmega1280) || defined(AVR_ATmega2560)|| defined(AVR_AT90CAN128)

#define EXTERNAL_NUM_INTERRUPTS 8

#else

#define EXTERNAL_NUM_INTERRUPTS 2

#endif

Still no change

Looking at the AST-CAN library there is no call out for wiring_private.h

But notice call for

//_____ I N C L U D E S ________________________________________________________

#include “config.h”

#include “can_compiler.h”

#include <avr/io.h>

#include <avr/interrupt.h>

But don’t have avr/io or avr /interrupt files anyway in my PC

Still Stump

Dave

14

Sorry forgot to mention still does not work after update

15

Good morning, Devan. The file wiring_private.h gets included when WInterrupts.c gets compiled which is where the attachInterrupt() function is defined. On my computer (Windows 10 machine) both of these files are located at <Arduino_install_directory>\hardware\arduino\avr\cores\arduino. I think if you do a file search starting where the Arduino IDE is installed on your machine, you should be able to find it. I hope that helps.

16

Hi M,

Seem the file location of my Arduino Window App program. So I have clean up my Arduino IDE and installed classic Arduino IDE 1.8.12. Located wiring_private.h and added

|| defined(AVR_AT90CAN128).

My original code did work but this code work.

const int buttonPin = 9; // the number of the pushbutton pin

const int ledPin = 13; // the number of the LED pin

// variables will change:

volatile int buttonState = 0; // variable for reading the pushbutton status

void setup() {

// initialize the LED pin as an output:

pinMode(ledPin, OUTPUT);

// initialize the pushbutton pin as an input:

pinMode(buttonPin, INPUT_PULLUP);

// Attach an interrupt to the ISR vector

attachInterrupt(0, pin_ISR, CHANGE);

}

void loop() {

// Nothing here!

}

void pin_ISR() {

buttonState = digitalRead(buttonPin);

digitalWrite(ledPin, buttonState);

}

But still stumped it works on any ButtonPin selected how??

And do I include second interrupt??

17

Also notice this does not work

attachInterrupt(MyPin, pin_ISR, CHANGE);

but this work

attachInterrupt(0, pin_ISR, CHANGE);

On any pin

Appricate comment still does solve the requirements

18

I would suggest trying

attachInterrupt(k,pin_ISR,CHANGE)

with k ranging from 0 to 7. If it works for 0 and 1 but not 2-7, then it means your update to wiring_private.h did not accomplish what it was intended to.

19

Yes you are correct. Works for 0 & 1 only.

20

And correct again reverting the wiring_private.h back to original.

Still works as above