How to set up interrupt registers on the stm32 microcontrollers?

Question

I wanted to toggle a led status by reading a push button status's using interrupt instead of polling. I'm using a Nucleo board F411 and a register based programming instead of that no sense HAL libraries(lol I'm just joking)

After reading the reference manual and the programming manual for the corresponding micro controller I thought that this code would work fine for the purpose of implementing interrupts...turns out it was not the case. I took at look at the debugging session to see how the corresponding registers changes and it does exactly as I need (the NVIC->ISERx, the priority bits, the unmasking bits, the rising or falling edge trigger, etc) so I actually have no idea what is wrong with my way of thinking about this problem.

By the way, I'm using a custom made (for me) class in order to easily set up any GPIO, I've tried this separately and I can say that the problem is not related to my library. You may think of this as just a configuration function for the GPIO as system_clock_config might be.

The thing is, whenever I push the button, nothing happens.

I get no compilation errors nor warnings.

Here is the code:

#include <main.h>
#include <GPIO_PORT.h>
#include <config.h>
#include <stm32f4xx.h>
#include <core_cm4.h>

/*GPIO_PORT is a custom made class that allows me to easily set any GPIO port as well 
 *as changing its attributes like pull up or pull down input mode, push-pull or open
 *drain output, change its mode (input or output), read and write to it, etc
 */

#define IO          GPIO_PORT


/*interrupt handler function for external interrupts from lines 10 to 15.
 * It's name goes according to the ones in the vector table generated in the startup.s file
 */
void EXTI15_10_IRQHandler (void){

    EXTI->PR = (1 << 13);           //clears the pending interrupt from line 13. this is done by writing a 1 to the register.
    GPIOA->ODR ^= (1 << 5);         //toggle PORTA5 output (this is where the LED is connected to)
}


int main(void){

    /*system_clock_settings():
     * function that selects whether to use internal or external oscillator as clock source
     */
    system_clock_settings('I');

    /*HAL_Init():
     * I wanted to use a little delay
     */
    HAL_Init();

    IO led('A', 5 , 0);                     //creates an IO class object which resembles a LED connected to PORTA0(output GPIO)

    IO boton1('C', 13, 1);                  //creates an IO class object which resembles a push button connected to PORTC13
    boton1.pupd_selection(-1);              //method of the class IO that selects no pull up neither pull down mode for this input.

    RCC->APB2ENR |= (1<<14);                //enables system configuration controller.

    SYSCFG->EXTICR[3] = (1<<5);             //bits [4:7] 0010 selects PORTC13 as EXTI source for line 13.


    EXTI->IMR |= (1<<13);                   //unmasking line 13 for the corresponding interrupt to be able to be triggered.

    EXTI->RTSR |= (1<<13);                  //rising edge triggers interrupt on line 13.

    NVIC_SetPriority(EXTI15_10_IRQn, 1);    //sets the priority for the EXTI15_10 lines of EXTI

    NVIC_EnableIRQ(EXTI15_10_IRQn);         //enables external interrupts coming from line 13

    while(1){


    }

}

Answer 1

Add :

NVIC_SetVector(EXTI15_10_IRQn, (uint32_t)&EXTI15_10_IRQHandler);

before your NVIC_Enable.
Best of luck to you!