I have written a program in Keil that blinks a LED via External GPIO Interrupt. Here is how I have configured it in STM32CubeMX:
At first, I enabled and configured RCC as you can see and configured PA0 for external interrupt and PB1 as output.
For clock source, I configured it as you can see below.
And for Pins
I checked the "EXTI Line 0 and Line 1 interrupt" checkbox. I'm not sure that checking this checkbox is necessary.
After configuration, I generated the source code below (main.c):
/* Includes ------------------------------------------------------------------*/
#include "stm32f0xx_hal.h"
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration----------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* Configure the system clock */
SystemClock_Config();
/* System interrupt init*/
HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0);
/* Initialize all configured peripherals */
MX_GPIO_Init();
/* USER CODE BEGIN 2 */
/* USER CODE END 2 */
/* USER CODE BEGIN 3 */
/* Infinite loop */
while (1)
{
}
/* USER CODE END 3 */
}
/** System Clock Configuration
*/
void SystemClock_Config(void)
{
RCC_ClkInitTypeDef RCC_ClkInitStruct;
RCC_OscInitTypeDef RCC_OscInitStruct;
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.HSICalibrationValue = 16;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL12;
RCC_OscInitStruct.PLL.PREDIV = RCC_PREDIV_DIV1;
HAL_RCC_OscConfig(&RCC_OscInitStruct);
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_SYSCLK;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1);
__SYSCFG_CLK_ENABLE();
}
/** Configure pins as
* Analog
* Input
* Output
* EVENT_OUT
* EXTI
*/
void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct;
/* GPIO Ports Clock Enable */
__GPIOF_CLK_ENABLE();
__GPIOA_CLK_ENABLE();
__GPIOB_CLK_ENABLE();
/*Configure GPIO pin : PA0 */
GPIO_InitStruct.Pin = GPIO_PIN_0;
GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/*Configure GPIO pin : PB1 */
GPIO_InitStruct.Pin = GPIO_PIN_1;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_HIGH;
HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
/* EXTI interrupt init*/
HAL_NVIC_SetPriority(EXTI0_1_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(EXTI0_1_IRQn);
}
/* USER CODE BEGIN 4 */
/* USER CODE END 4 */
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t* file, uint32_t line)
{
/* USER CODE BEGIN 6 */
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif
/**
* @}
*/
/**
* @}
*/
For handling External GPIO Interrupt, I opened 'stm32f0xx_it.c' file and placed HAL_GPIO_TogglePin(GPIOB , GPIO_PIN_1) between HAL_NVIC_ClearPendingIRQ(EXTI0_1_IRQn) and HAL_GPIO_EXTI_IRQHandler(GPIO_PIN_0) then the interrupt source code is this:
/* Includes ------------------------------------------------------------------*/
#include "stm32f0xx_hal.h"
#include "stm32f0xx.h"
#include "stm32f0xx_it.h"
/* External variables --------------------------------------------------------*/
/******************************************************************************/
/* Cortex-M4 Processor Interruption and Exception Handlers */
/******************************************************************************/
/**
* @brief This function handles System tick timer.
*/
void SysTick_Handler(void)
{
HAL_IncTick();
HAL_SYSTICK_IRQHandler();
}
/**
* @brief This function handles EXTI Line 0 and Line 1 interrupts.
*/
void EXTI0_1_IRQHandler(void)
{
HAL_NVIC_ClearPendingIRQ(EXTI0_1_IRQn);
HAL_GPIO_TogglePin(GPIOB , GPIO_PIN_1);
HAL_GPIO_EXTI_IRQHandler(GPIO_PIN_0);
}
I built the HEX file correctly and downloaded it to the MCU (without any problem or errors). Now, when I run it, there is a problem. The LED blinks quickly even when I don't press the button. Look:
Why? Also when I press the button, it toggles the LED but it blinks between each press. It looks like something changes the state of PB1 pin. What's the problem? How can I correct it?
