Posted on June 12, 2016 at 08:51Hi!
Im trying to use two EXTI on PE2 and PE3 pins simultaneously. Two push bottons are connected to these two pins with a pull-up resistor and a capacitor filter prohibitting debounce phenomenon. As shown in the code below, in one ISR ''h'' is increased and in the other ''n''. the problem is that when I press one of the bottoms both ''h'' and ''n'' increase multiple times. On oscope PE2 and PE3 signals are correct but the stm32f4 processor is unpredictable. I don't understand what is happening!
#include ''stm32f4xx.h''
EXTI_InitTypeDef EXTI_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
uint16_t n,h=0;
static void EXTI_Configuration(void);
int main(void)
{
SystemInit();
// SysTick_Config(SystemCoreClock/1000);
EXTI_Configuration();
while(1);
}
static void EXTI_Configuration(void)
{
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE , ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Pin =GPIO_Pin_2|GPIO_Pin_3;
GPIO_Init(GPIOE, &GPIO_InitStructure);
SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOE, EXTI_PinSource2);
SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOE, EXTI_PinSource3);
EXTI_InitStructure.EXTI_Line = EXTI_Line2|EXTI_Line3;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
EXTI_Init(&EXTI_InitStructure);
NVIC_InitStructure.NVIC_IRQChannel = EXTI2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQn;
NVIC_Init(&NVIC_InitStructure);
}
void EXTI2_IRQHandler(void){
if(EXTI_GetITStatus(EXTI_Line2) != RESET)
{
n++;
EXTI_ClearITPendingBit(EXTI_Line2); //Clear the EXTI line 2 pending bit
}
}
void EXTI3_IRQHandler(void){
if(EXTI_GetITStatus(EXTI_Line3) != RESET)
{
h++;
EXTI_ClearITPendingBit(EXTI_Line3);
}
}
