Posted on July 11, 2016 at 09:15Hi,
I've been trying to get going with this dev. board, but I ran into problems with the external interrupt. No matter what I choose in SYSCFG->EXTICR[0], the PA0 interrupt is always the selected one. Can anyone of you see what am I doing wrong? The code compiles and the interrupt on PA0 works fine, just that I cannot choose anything else!
/* EXTERNAL INTERRUPTS TEST */
/* Board STM32F0Discovery */
/* Trigger interrupt on Pin 0, PORTA and toggle the LED */
/* Select Pin 0, PORTB and check no interrupt will be triggered then */
&sharpinclude ''stm32f0xx.h''
void delay (int a); // Function Prototype
int EXTI0Flag = 0;
int ledStatus = 0x0100;
int main(void)
{
/* GPIOC GPIOA Periph clock enable */
RCC->AHBENR |= RCC_AHBENR_GPIOAEN;
RCC->AHBENR |= RCC_AHBENR_GPIOBEN;
RCC->AHBENR |= RCC_AHBENR_GPIOCEN;
GPIOA->MODER &= ~(GPIO_MODER_MODER0);
GPIOB->MODER &= ~(GPIO_MODER_MODER0);
GPIOC->MODER |= (GPIO_MODER_MODER8_0);
GPIOC->OTYPER &= ~(GPIO_OTYPER_OT_8);
// Ensure push pull mode selected for output pins--default
GPIOA->OSPEEDR |= (GPIO_OSPEEDER_OSPEEDR0);
GPIOB->OSPEEDR |= (GPIO_OSPEEDER_OSPEEDR0);
GPIOC->OSPEEDR |= (GPIO_OSPEEDER_OSPEEDR8);
//Ensure maximum speed setting (even though it is unnecessary)
GPIOA->PUPDR &= ~(GPIO_PUPDR_PUPDR0);
GPIOB->PUPDR &= ~(GPIO_PUPDR_PUPDR0);
GPIOC->PUPDR &= ~(GPIO_PUPDR_PUPDR8);
//Ensure all pull up pull down resistors are disabled PA0 is connected to external pulldown on STM32F0Discovery baord
SYSCFG->EXTICR[0] = 0x0001; //0x0000 for PA0 and 0x0001 for PB0
//1. clear bits 3:0 in the SYSCFG_EXTICR1 reg to amp EXTI Line to NVIC for PA0
// clear bits 3:1 in the SYSCFG_EXTICR1 reg to amp EXTI line to NVIC for PB0
EXTI->RTSR = EXTI_RTSR_TR0;
// 2.Set interrupt trigger to rising edge
EXTI->IMR = EXTI_IMR_MR0; // 3. unmask EXTI0 line
NVIC_SetPriority(EXTI0_1_IRQn, 1); //4. Set Priority to 1
NVIC_EnableIRQ(EXTI0_1_IRQn); // 5. Enable EXTI0_1 interrupt in NVIC (do 4 first)
while(1)
{
if(EXTI0Flag)
{
EXTI0Flag = 0;
GPIOC -> ODR ^= ledStatus; // Toggle the LED if you get here
}
}
}
void EXTI0_1_IRQHandler(void)
{
if( (EXTI->IMR & EXTI_IMR_MR0) && (EXTI->PR & EXTI_PR_PR0))
{
EXTI0Flag = 1;
delay(50000);
while(GPIOA->IDR & GPIO_IDR_0){} // Wait for the button
EXTI->PR |= EXTI_PR_PR0 ; // Clear the flag
}
}
void delay (int a)
{
volatile int i,j;
for (i=0 ; i < a ; i++)
{
j++;
}
return;
}
#syscfg-exti
