Posted on October 28, 2017 at 17:37Hi ladies, guys,
I am currently working on a project, so I am getting used to work with SMT32 MCUs and more particularly with STM32F411RE. I have built a C program just to blink the led user, in order to reduce flash and RAM as much as possible than the program bed gives us, with a lot of functions, libraries, that we don't use at all.
However, when I flash it on my board, that does not work but the firmware given by bed works so my code is wrong. But I am working on it for many hours and I need some advice and another point of view. Could you tell me what is wrong ?
So here it is :
&sharpinclude 'stm32f4xx.h'
int main() {
/* HSI -> SYSCLK */
RCC->CR |= (1u << 0) ; /* bit 0 at 1 to select HSI */
RCC->CFGR = RCC->CFGR & 0xFFFFFFFC ; /* HSI == SYSCLK */
RCC->PLLCFGR = RCC->PLLCFGR & 0xFFBFFFFF ; /* bit 22 a 0 (2MHz mini) */
RCC->PLLCFGR = RCC->PLLCFGR | 0x00000F0A ; /* 96 MHz (16*60/10) */
RCC->PLLCFGR = RCC->PLLCFGR | 0x02000000 ; /* 48 MHz (96/2) */
RCC->CR = RCC->CR & 0xFFFCFFFF ; /* 48 MHz */
RCC->CR = RCC->CR | 0x02000000 ; /* 48 MHz */
/* PUSH-PULL OUTPUT for GPIOA and PA5 for LED user */
RCC->AHB1ENR |= (1u << 0) ; /* peripheral clock enabled (bit 0 GPIOEN) */
GPIOA->MODER |= (1u << 10) ; /* byte 10 set to 1 */
GPIOA->OTYPER &= ~(1u << 5) ; /* byte 5 put to 0 for output push pull */
/* Configuration of the timer */
RCC->APB1ENR |= (1u << 0) ; /* Enable clock TIM2 (BIT 0 register APB1ENR) */
TIM2->ARR = 6855 ;
/*Autoreaload
*/
TIM2->PSC = 10000 ;
/* Prescaler
*/
TIM2->DIER |= (1u << 0) ; ; /* Enable interrupt for tim2 */
/* Autorisation interruption */
NVIC->ISER[0] |= (1u << 28); /* Enable interrupt 28 ofr TIM2 */
NVIC->IP[28] = NVIC->IP[28] | (7 << 4); /* Priorit� (7) */
SYSCFG->EXTICR[2] &= 0xFFFFFF0F ;
EXTI->IMR |= ( 1u << 5 ) ; /* Masque interruption desactivee EXTI_IMR register */
/* Lancement du timer */
TIM2->CR1 |= (1u << 0) ; /* Counter is on */
while(1)
{
}
return 0 ;
}
void TIM2_IRQHandler(void){
/* LED on or off */
TIM2->SR &= ~( 1u << 0 ) ; /* UIF puts at 0 */
GPIOA->ODR = GPIOA->ODR ^ (1u << 5);
}
Thanks a lot !
Best !
#incomplete-code
