/*
Za budjenje se koristi interrupt ili RTC
Za RTC Omogućiti LSE oscilator (Low-Speed External) 
za precizno merenje vremena u low-power modovima.
*/

#include "stm32f1xx_hal.h"

/* Function prototypes */
void SystemClock_Config(void);
void Enter_Sleep_Mode(void);
void Enter_Stop_Mode(void);
void Enter_Standby_Mode(void);

int main(void)
{
    HAL_Init();
    SystemClock_Config();

    /* Example: Enter Stop mode */
    Enter_Stop_Mode();

    while (1)
    {
        /* Main loop code */
    }
}

void Enter_Sleep_Mode(void)
{
    __enable_irq();
    HAL_PWR_EnterSLEEPMode(PWR_MAINREGULATOR_ON, PWR_SLEEPENTRY_WFI);
}

void Enter_Stop_Mode(void)
{
    HAL_PWR_EnableSleepOnExit();
    HAL_PWR_EnterSTOPMode(PWR_LOWPOWERREGULATOR_ON, PWR_STOPENTRY_WFI);
    SystemClock_Config();
}

void Enter_Standby_Mode(void)
{
    __HAL_PWR_CLEAR_FLAG(PWR_FLAG_WU);
    HAL_PWR_EnableWakeUpPin(PWR_WAKEUP_PIN1);
    HAL_PWR_EnterSTANDBYMode();
}

void SystemClock_Config(void)
{
    RCC_OscInitTypeDef RCC_OscInitStruct = {0};
    RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

    /* Initialize HSE Oscillator */
    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
    RCC_OscInitStruct.HSEState = RCC_HSE_ON;
    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
    RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
    RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
    HAL_RCC_OscConfig(&RCC_OscInitStruct);

    /* Initialize CPU, AHB, and APB buses clocks */
    RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2;
    RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
    RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
    HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2);

    /* Configure the SysTick interrupt time */
    HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq() / 1000);
    HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);
}