STM32 - more buttons pressed interrupt

Question

I am using STM32L433CCT6 and I am programming it with eclipse and code genereted by STM32CubeMX.

I would like to ask you, if is possible to add iterrupt that will be called, if i press two (or more) buttons.

I mean something like this interrupt

void EXTI2_IRQHandler(void) {
    HAL_NVIC_ClearPendingIRQ(EXTI2_IRQn);
    HAL_GPIO_EXTI_IRQHandler(GPIO_PIN_2);
    {
        /* EXTI line interrupt detected*/
        if (__HAL_GPIO_EXTI_GET_IT(GPIO_PIN_2) != SET) {

            //what I would like to do when is detected rising/falling edge

            __HAL_GPIO_EXTI_CLEAR_IT(GPIO_PIN_2);
            HAL_GPIO_EXTI_Callback(GPIO_PIN_2);

        }
    }
}

but it will be called when I detect 2 pressed buttons, instead of rising or falling edge.

Thank you for your reply.

Answer 1

No, it is not possible - you need additional logic for that.

What's more - some EXTI lines serve multiple GPIOs at once.

A reasonable option would be to save the interrupt time (Hal_GetTick() of memory serves) and in the main loop check if the button times are close together.

Answer 2

Buttons and EXIT is a very bad companion. For many reasons - there is a lots of information about it across the internet. The correct approach is to check it in the timer interrupt.

Here you have the example:

https://www.diymat.co.uk/arm-three-function-click-double-and-long-click-button-library-timer-interrupt-driven/