File content as of revision 0:c5e2a50f0d5d:

#include "mbed.h"
#include "stm32f4xx.h"
#include "stm32f4xx_hal_tim_ex.h"
#include "stm32f4xx_hal_conf.h"



int16_t count1 = 10; 


void EXTI0_IRQHandler(void)
{
    HAL_NVIC_ClearPendingIRQ(EXTI0_IRQn);
    HAL_GPIO_EXTI_IRQHandler(GPIO_PIN_0);
}

void HAL_GPIO_EXTI_Callback (uint16_t GPIO_Pin)
{
    if (GPIO_Pin == GPIO_PIN_0) {
        count1 = 0;
    }
}

int main()
{
    HAL_Init();

    GPIO_InitTypeDef GPIO_InitStruct;
    __GPIOA_CLK_ENABLE();
    GPIO_InitStruct.Pin = GPIO_PIN_0;  //PA0 as interrupt test
    GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;
    GPIO_InitStruct.Pull = GPIO_PULLDOWN;
    GPIO_InitStruct.Speed = GPIO_SPEED_FAST;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
    HAL_NVIC_SetPriorityGrouping(NVIC_PRIORITYGROUP_4);
    HAL_NVIC_SetPriority(SysTick_IRQn, 0, 1);
    HAL_NVIC_SetPriority(EXTI0_IRQn, 0, 1);
    HAL_NVIC_EnableIRQ(EXTI0_IRQn);


    while (1) {

        printf("loop%d\r\n", count1);
        wait(1);


    }

}