STM32F103 Programming - 7-Pin Input Function - Button (Interrupt)

Turn on the AFIO clock. External interrupt, remapping, multiplexing function? When configuring the values ​​in the six AFIO registers, you need to turn on the AFIO clock.

void EXTI0_Config(void)

{

  /* Enable GPIOA clock */

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

  /* Configure PA.00 pin as input floating */

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;

  GPIO_Init(GPIOA, &GPIO_InitStructure);

  /* Enable AFIO clock */

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);

  /* Connect EXTI0 Line to PA.00 pin */

  GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource0);

  /* Configure EXTI0 line */

  EXTI_InitStructure.EXTI_Line = EXTI_Line0;

  EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;

  EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;  

  EXTI_InitStructure.EXTI_LineCmd = ENABLE;

  EXTI_Init(&EXTI_InitStructure);

  /* Enable and set EXTI0 Interrupt to the lowest priority */

  NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;

  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x0F;

  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x0F;

  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

  NVIC_Init(&NVIC_InitStructure);

}

After copying, many errors are found, which need to be solved one by one. The error solution in the figure below: LIB adds two library files misc.c and stm32f10x_exit.c.

Interrupt handling function:

void EXTI3_IRQHandler(void)

{

  if (EXTI_GetITStatus(EXTI_Line3) != RESET)

  {

    /* Turn ON LED2 */

GPIOD->BRR |= (1<<12);

    /* Clear the  EXTI line 0 pending bit */

    EXTI_ClearITPendingBit(EXTI_Line3);

  }

Remember to add EXTI3_Config() in the main program. You can also follow the example on the official website to do the flip. The specific implementation is:

Set GPIOD->BRR |= (1<

Finally, please note that when configuring the interrupt, we set the external interrupt to be triggered on the rising edge: EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;