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saviphagura
saviphagura
Associate II
April 6, 2014
Question

STM32F4 User Push Button Interrupt Issue

Posted on April 06, 2014 at 05:22

Hey,

I'm currently working on a project for my class with the STM32F4 board, and am having difficulty trying to configure the user push button to cause an interrupt. I have used the F3 board a few times, and have made the same approach to configuring and handling the user button, however, can not get it to function correctly on the F4. - I am using the IAR Embedded Workbench IDE - I have initialized the pin as follows: 

STM_EVAL_PBInit(BUTTON_USER, BUTTON_MODE_EXTI);

- My interrupt handler is as follows: 

void EXTI0_IRQHandler(void)
{
if(EXTI_GetITStatus(EXTI_Line0) != RESET){
button_push = 1; // Global variable
EXTI_ClearFlag(EXTI_Line0);
}
EXTI_ClearITPendingBit(EXTI_Line0);
}

I apologize if I have left any other details out. I have tried to configure EXTI0 without the use of ''STM_EVAL_PBInit'', and still was unable to configure the button. Any help would be much appreciated! Thanks! #stm32f4 #discovery #exti
This topic has been closed for replies.

3 replies

Tesla DeLorean
Tesla DeLorean
Guru
April 6, 2014
Posted on April 06, 2014 at 06:22

Configured NVIC? 

// STM32F4-Discovery ORANGE/GREEN LED Toggle from USER Button - sourcer32@gmail.com
#include ''stm32f4_discovery.h''
/**************************************************************************************/
void EXTI0_IRQHandler(void)
{
if(EXTI_GetITStatus(EXTI_Line0) != RESET)
{
/* Clear the EXTI line 0 pending bit */
EXTI_ClearITPendingBit(EXTI_Line0);
/* Toggle LED3 */
STM_EVAL_LEDToggle(LED3);
/* Toggle LED4 */
STM_EVAL_LEDToggle(LED4);
}
}
/**************************************************************************************/
int main(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
EXTI_InitTypeDef EXTI_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
/* Enable GPIOA clock */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
/* Enable SYSCFG clock */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
/* Configure PA0 pin as input floating */
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_Init(GPIOA, &GPIO_InitStructure);
/* Connect EXTI Line0 to PA0 pin */
SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOA, EXTI_PinSource0);
/* Configure EXTI Line0 */
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 EXTI Line0 Interrupt to the lowest priority */
NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x01;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x01;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
/* Initialize LEDs mounted on STM32F4-Discovery board */
STM_EVAL_LEDInit(LED3);
STM_EVAL_LEDInit(LED4);
STM_EVAL_LEDOn(LED3);
STM_EVAL_LEDOff(LED4);
while(1); // Do not want to exit
}
/**************************************************************************************/
#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 can add his own implementation to report the file name and line number,
ex: printf(''Wrong parameters value: file %s on line %d

'', file, line) */
while (1)
{}
}
#endif
/**************************************************************************************/

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saviphagura
saviphaguraAuthor
Associate II
April 6, 2014
Posted on April 06, 2014 at 06:49

Thanks for the quick reply.

I've tried that, and it did not work. I even copied/pasted that code and it did not work. I believe I may be missing some file in my project. I created a new blank project according to the following post:

http://dccharacter.blogspot.com/2013/03/creating-new-project-for-stm32f4.html

I think the 

stm32f4xx_it.c and stm32f4xx_it.h files I used may be causing problems. Any advice on which to use? This is my first time creating the blank project.

Tesla DeLorean
Tesla DeLorean
Guru
April 6, 2014
Posted on April 06, 2014 at 07:03

I don't use IAR, but would suggest you look at the template projects in STM32F4-Discovery_FW_v1.1.0\Project\Peripheral_Examples and clone one of those as a starting point.

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