/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file    Examples_LL/COMP/COMP_CompareGpioVsVrefInt_OutputGpio_Init/Src/main.c
  * @author  MCD Application Team
  * @brief   This example shows how to use a comparator peripheral
  *          to compare a voltage level applied on a GPIO pin
  *          versus the internal voltage reference (VrefInt),
  *          comparator output is connected to a GPIO.
  *          This example is based on the STM32WLxx COMP LL API;
  *          Peripheral initialization done using LL unitary services functions.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2020 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */

/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/

/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_COMP1_Init(void);
/* USER CODE BEGIN PFP */
void     Activate_COMP(void);
void     LED_On(void);
void     LED_Off(void);

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{
  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */

  /* System interrupt init*/
  NVIC_SetPriorityGrouping(NVIC_PRIORITYGROUP_4);

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_COMP1_Init();
  /* USER CODE BEGIN 2 */

  /* Activate comparator */
  Activate_COMP();

  /* Lock comparator instance */
  //LL_COMP_Lock(COMP1);

  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* Set LED state in function of state of GPIO connected to                */
    /* comparator output.                                                     */
    /* Note: State of GPIO is monitored for the purpose of this example.      */
    /*       An alternate solution is to monitor directly comparator output   */
    /*       using function "LL_COMP_ReadOutputLevel()".                      */
    if (LL_GPIO_IsInputPinSet(GPIOB, LL_GPIO_PIN_0) != 0)
    {
      LED_On();
    }
    else
    {
      LED_Off();
    }
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  LL_FLASH_SetLatency(LL_FLASH_LATENCY_0);
  while(LL_FLASH_GetLatency() != LL_FLASH_LATENCY_0)
  {
  }

  LL_PWR_SetRegulVoltageScaling(LL_PWR_REGU_VOLTAGE_SCALE2);
  LL_RCC_HSI_Enable();

   /* Wait till HSI is ready */
  while(LL_RCC_HSI_IsReady() != 1)
  {
  }

  LL_RCC_HSI_SetCalibTrimming(64);
  LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_HSI);

   /* Wait till System clock is ready */
  while(LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_HSI)
  {
  }

  LL_RCC_SetAHBPrescaler(LL_RCC_SYSCLK_DIV_1);
  LL_RCC_SetAHB3Prescaler(LL_RCC_SYSCLK_DIV_1);
  LL_RCC_SetAPB1Prescaler(LL_RCC_APB1_DIV_1);
  LL_RCC_SetAPB2Prescaler(LL_RCC_APB2_DIV_1);

  LL_Init1msTick(16000000);

  /* Update CMSIS variable (which can be updated also through SystemCoreClockUpdate function) */
  LL_SetSystemCoreClock(16000000);
}

/**
  * @brief COMP1 Initialization Function
  * @param None
  * @retval None
  */
static void MX_COMP1_Init(void)
{

  /* USER CODE BEGIN COMP1_Init 0 */

  /* USER CODE END COMP1_Init 0 */

  LL_COMP_InitTypeDef COMP_InitStruct = {0};

  LL_GPIO_InitTypeDef GPIO_InitStruct = {0};

  LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_GPIOB);
  /**COMP1 GPIO Configuration
  PB4   ------> COMP1_INP
  */
  GPIO_InitStruct.Pin = LL_GPIO_PIN_4;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_ANALOG;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  LL_GPIO_Init(GPIOB, &GPIO_InitStruct);

  /* USER CODE BEGIN COMP1_Init 1 */
  /* Configure GPIO connected to the comparator output */
  /* Note: Other GPIO are available as comparator output,                     */
  /*       refer to device datasheet.                                         */
  /* Enable GPIO clock */
  LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_GPIOB);

  /* Configure GPIO output type */
  LL_GPIO_SetPinOutputType(GPIOB, LL_GPIO_PIN_0, LL_GPIO_OUTPUT_PUSHPULL);

  /* Configure GPIO speed */
  LL_GPIO_SetPinSpeed(GPIOB, LL_GPIO_PIN_0, LL_GPIO_SPEED_FREQ_HIGH);

  /* Configure GPIO in alternate function mode to be used as COMP output */
  LL_GPIO_SetPinMode(GPIOB, LL_GPIO_PIN_0, LL_GPIO_MODE_ALTERNATE);
  LL_GPIO_SetAFPin_0_7(GPIOB, LL_GPIO_PIN_0, LL_GPIO_AF_12);

  /* USER CODE END COMP1_Init 1 */
  COMP_InitStruct.PowerMode = LL_COMP_POWERMODE_MEDIUMSPEED;
  COMP_InitStruct.InputPlus = LL_COMP_INPUT_PLUS_IO1;
  COMP_InitStruct.InputMinus = LL_COMP_INPUT_MINUS_VREFINT;
  COMP_InitStruct.InputHysteresis = LL_COMP_HYSTERESIS_NONE;
  COMP_InitStruct.OutputPolarity = LL_COMP_OUTPUTPOL_NONINVERTED;
  COMP_InitStruct.OutputBlankingSource = LL_COMP_BLANKINGSRC_NONE;
  LL_COMP_Init(COMP1, &COMP_InitStruct);
  LL_COMP_SetCommonWindowMode(__LL_COMP_COMMON_INSTANCE(COMP1), LL_COMP_WINDOWMODE_DISABLE);

  /* Wait loop initialization and execution */
  /* Note: Variable divided by 2 to compensate partially CPU processing cycles */
  __IO uint32_t wait_loop_index = 0;
  wait_loop_index = (LL_COMP_DELAY_VOLTAGE_SCALER_STAB_US * (SystemCoreClock / (1000000 * 2)));
  while(wait_loop_index != 0)
  {
    wait_loop_index--;
  }
  LL_EXTI_DisableEvent_0_31(LL_EXTI_LINE_21);
  LL_EXTI_DisableIT_0_31(LL_EXTI_LINE_21);
  /* USER CODE BEGIN COMP1_Init 2 */

  /* USER CODE END COMP1_Init 2 */

}

/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
  LL_GPIO_InitTypeDef GPIO_InitStruct = {0};

  /* GPIO Ports Clock Enable */
  LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_GPIOB);

  /**/
  LL_GPIO_ResetOutputPin(LED2_GPIO_Port, LED2_Pin);

  /**/
  GPIO_InitStruct.Pin = LED2_Pin;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_OUTPUT;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_LOW;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  LL_GPIO_Init(LED2_GPIO_Port, &GPIO_InitStruct);

}

/* USER CODE BEGIN 4 */
/**
  * @brief  Perform comparator activation procedure
  *         (COMP instance: COMP1).
  * @note   Operations:
  *         - Enable comparator instance
  *         - Wait for comparator startup time
  *           (required to reach propagation delay specification)
  * @param  None
  * @retval None
  */
void Activate_COMP(void)
{
  __IO uint32_t wait_loop_index = 0;

  /* Enable comparator */
  LL_COMP_Enable(COMP1);

  /* Delay for comparator startup time.                                       */
  /* Compute number of CPU cycles to wait for, from delay in us.              */
  /* Note: Variable divided by 2 to compensate partially                      */
  /*       CPU processing cycles (depends on compilation optimization).       */
  /* Note: If system core clock frequency is below 200kHz, wait time          */
  /*       is only a few CPU processing cycles.                               */
  wait_loop_index = ((LL_COMP_DELAY_STARTUP_US * (SystemCoreClock / (100000 * 2))) / 10);
  while(wait_loop_index != 0)
  {
    wait_loop_index--;
  }
}
/**
  * @brief  Turn-on LED2.
  * @param  None
  * @retval None
  */
void LED_On(void)
{
  /* Turn LED2 on */
  LL_GPIO_SetOutputPin(LED2_GPIO_Port, LED2_Pin);
}

/**
  * @brief  Turn-off LED2.
  * @param  None
  * @retval None
  */
void LED_Off(void)
{
  /* Turn LED2 off */
  LL_GPIO_ResetOutputPin(LED2_GPIO_Port, LED2_Pin);
}


/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler_Debug */
  /* User can add his own implementation to report the HAL error return state */

  /* USER CODE END Error_Handler_Debug */
}

#ifdef  USE_FULL_ASSERT
/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{
  /* USER CODE BEGIN 6 */
  /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d", file, line) */

  /* Infinite loop */
  while (1)
  {
  }
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
