#include "stm32f4xx.h" // Device header

void init_gpio(void);
void init_timer(void);
void led_blinking(void);


static volatile uint32_t TimeTick;
volatile int capture1;
volatile int capture2;

void SysTick_Handler() {
if(TimeTick)
{
TimeTick--;
}
}

void TIM3_IRQHandler(){
if(TIM3->SR&2){
}
}


int main(){
SysTick_Config(SystemCoreClock/1000);
init_gpio();
init_timer();
while(1){
led_blinking();
}

}

void init_gpio(){
/*Configure pins 12, 13, 14, 15 on port D*/
RCC->AHB1ENR |= RCC_AHB1ENR_GPIODEN;
GPIOD->MODER = 0x55000000;

/*Cofigure TIM3, Channel 1 (PA6)*/
RCC->AHB1ENR |= RCC_AHB1ENR_GPIOAEN;
GPIOA->MODER = GPIO_MODER_MODER6_0;
GPIOA->AFR[0] = 0x02000000;
}

void init_timer(){
RCC->APB1ENR |= RCC_APB1ENR_TIM3EN;
TIM3->CCMR1 |= TIM_CCMR1_CC1S_0; // CH1 to PA6
TIM3->CCMR1 |= (TIM_CCMR1_IC1F_0 | TIM_CCMR1_IC1F_1); //
TIM3->CCER &= ~TIM_CCER_CC1P;
TIM3->CCER &= ~TIM_CCER_CC1NP;
TIM3->CCMR1 &= ~TIM_CCMR1_IC1PSC; //
TIM3->CCER |= TIM_CCER_CC1E; //
TIM3->DIER |= TIM_DIER_CC1IE; //
TIM3->CR1 |= TIM_CR1_CEN; //
NVIC_EnableIRQ(TIM3_IRQn);
}


void DelaymS(uint32_t time){
TimeTick = time;
while(TimeTick);
}

void led_blinking(){
GPIOD->BSRRH = GPIO_BSRR_BS_12 | GPIO_BSRR_BS_13 | GPIO_BSRR_BS_14 | GPIO_BSRR_BS_15; //LEDs On
DelaymS(5000);//Delay using SysTick
GPIOD->BSRRL = GPIO_BSRR_BS_12 | GPIO_BSRR_BS_13 | GPIO_BSRR_BS_14 | GPIO_BSRR_BS_15; //LEDs Off
DelaymS(5000);
}

GPIOA->MODER = GPIO_MODER_MODER6_1;

capture1 = capture2 = 0;
    capture2 = TIM3->CCR1;
    t = capture2 - capture1;