PC2 Line2 causing an EXTI interrupt on PC3 Line3

[jean_prieur]

Posted on July 17, 2014 at 19:23

Hello everybody,

I have a problem with one of my EXTI interrupt. I have two hardware switches, one is linked to the PC2 PIN, the other is linked to the PC3 pin. I also configure EXTI interrupts on the PC2 and PC3 (so Line2 and Line3). - When I press the PC3 switch, I have as expected an interrupt on EXTI3_IRQHandler. - When I press the PC2, I have an interrupt on EXTI2_IRQHandler, but sometime also an interrupt on EXTI3_IRQHandler (about one in five times). I don't understand why, because the PC3 and PC2 tracks are not linked together on my board. When I press the PC2 switch, PC2 pin = 5V and the PC3 pin is always 0V. I think I try every GPIO definition but nothing change. This is my code:

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2 | GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_Init(GPIOC, &GPIO_InitStructure);

void
Interrupt_Config_Line3(
void
)
{
// INIT TYPEDEF
NVIC_InitTypeDef NVIC_InitStructure;
EXTI_InitTypeDef EXTI_InitStructure;
// Connect EXTI Line3 to PC3 pin
SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOC, EXTI_PinSource3);
// Configure EXTI Line3
EXTI_InitStructure.EXTI_Line = EXTI_Line3;
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 Line3 Interrupt to the high priority
NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQn;
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_4);
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = PREAMPTION_PRIORITY_HIGH;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
void
Interrupt_Config_Line2(
void
)
{
// INIT TYPEDEF
NVIC_InitTypeDef NVIC_InitStructure;
EXTI_InitTypeDef EXTI_InitStructure;
// Connect EXTI Line2 to PC2 pin
SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOC, EXTI_PinSource2);
// Configure EXTI Line2
EXTI_InitStructure.EXTI_Line = EXTI_Line2;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising_Falling;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);
// Enable and set EXTI Line2 Interrupt to the low priority
NVIC_InitStructure.NVIC_IRQChannel = EXTI2_IRQn;
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_4);
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = PREAMPTION_PRIORITY_LOW;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}

void
EXTI3_IRQHandler(
void
)
{
if
(EXTI_GetITStatus(EXTI_Line3) != RESET)
{
// Do something
EXTI_ClearITPendingBit (EXTI_Line3);
}
}
void
EXTI2_IRQHandler(
void
)
{
if
(EXTI_GetITStatus(EXTI_Line2) != RESET)
{
// Do something
EXTI_ClearITPendingBit (EXTI_Line2);
}
}

Do you have any ideas? Thanks a lot!