HM Yoong

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11 years, 4 months ago.

Feature request: Argument to interrupt handler

Hi:

Possible to update InterruptIn class to include argument to interrupt handler? Instead of

void rise(void (*fptr)(void));

I propose this

void rise(void (*fptr)(void *arg = NULL), void *arg);

The new rise() will assign pointer to the function to its internal rise interrupt handler, and also assign the address or arg into it.

For example,

#include "mbed.h"
 
InterruptIn button(p5);
DigitalOut  Leds[] = { (LED1), (LED2), (LED3)};
DigitalOut  flash(LED4);
int         i = 0; 

// LED1 .. LED4 will be lighted up in sequence at each press of the button 
void flip(void *argv) {
    int n = (int) *argv;
    Leds[n] = !leds[n];
    n = ++n % 3;
    (int) (*argv) = n;
}
 
int main() {
    button.rise(&flip, &i);
    while(1) {           // wait around, interrupts will interrupt this!
        flash = !flash;
        wait(0.25);
    }
}

Suggestion?

Question relating to:

Last updated: 30 Apr 2020

errored program

posted by siddhartha A R 24 Jul 2017

2 Answers

HM Yoong
poster
11 years, 3 months ago.

I think it again, when an interrupt is trigger, no one is there to pass argument to a generic interrupt handler.

In other words, each interrupt handler has to be created for each InterruptIn object if it is intended to do different actions.

Accepted Answer
Erik -
11 years, 4 months ago.

Well I can see it sometimes being useful, but not for interruptIn. Why not just use 'i' directly here in your interrupt handler?

Precisely i was using "i"

posted by HM Yoong 24 Jul 2017