stm32f4xx_it.c overwirtten if I update the configuration

[JHanc.1]

I'm new to STM32 and am trying to get a couple of simple things working at this point. I am trying to generate and handle a GPIO interrupt on PA0 using FreeRTOS and I have no trouble with that. All the examples I've seen say to modify the ISR at stm32f4xx_it.c.

The problem is that anytime I make a change to the STM32 configuration and generate the code again, it overwrites my stm32f4xx_it.c file and the changes I made to the ISR are lost.

Surely I'm missing something simple. Any tips are appreciated! Thanks!

[joemccarr]

You have to put the code you want to add in between these comments. Then CubeMX will not over write what you have

in there. Just an example

/* USER CODE END SysTick_IRQn 0 */

code here will not be overwritten

 /* USER CODE BEGIN SysTick_IRQn 1 */

[JHanc.1]

Thanks for both of these replies. It's perfectly obvious now that I see it.

[KnarfB]

The code within the USER CODE BEGIB/END "brackets" should not be overwritten by the tools.

When you generate the code, the native IRQ Handler will already contain a call like

void EXTI15_10_IRQHandler(void)
{
 /* USER CODE BEGIN EXTI15_10_IRQn 0 */
 
 /* USER CODE END EXTI15_10_IRQn 0 */
 HAL_GPIO_EXTI_IRQHandler(GPIO_PIN_11);
 /* USER CODE BEGIN EXTI15_10_IRQn 1 */
 
 /* USER CODE END EXTI15_10_IRQn 1 */
}

HAL_GPIO_EXTI_IRQHandle finally dispatches to a callback HAL_GPIO_EXTI_Callback. If you stick to HAL (not everybody likes that), you don't modify stm32f4xx_it.c at all but implement your own callback anywhere, e.g. in a main.c USER CODE section:

/* USER CODE BEGIN 0 */
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{
 // do what you want
}
/* USER CODE END 0 */