/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file    Examples_LL/USART/USART_Communication_Tx_VCP_Init/Src/main.c
  * @author  MCD Application Team
  * @brief   This example describes how to send bytes over USART IP using
  *          the STM32WLxx USART 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 */

#if (USE_TIMEOUT == 1)
#define USART_SEND_TIMEOUT_TXE_MS 10
#define USART_SEND_TIMEOUT_TC_MS  20
#endif /* USE_TIMEOUT */

/* USER CODE END PD */

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

/* USER CODE END PM */

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

/* USER CODE BEGIN PV */

#if (USE_TIMEOUT == 1)
uint32_t Timeout = 0; /* Variable used for Timeout management */
#endif /* USE_TIMEOUT */
__IO uint8_t ubButtonPress = 0;
uint8_t ubSend = 0;
const uint8_t aStringToSend[] = "STM32WLxx USART LL API Example : TX in Polling mode\r\nConfiguration UART 115200 bps, 8 data bit/1 stop bit/No parity/No HW flow control\r\n";

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART2_UART_Init(void);
/* USER CODE BEGIN PFP */
void     LED_On(void);
void     LED_Off(void);
#if (USE_TIMEOUT == 1)
void     LED_Blinking(uint32_t Period);
#endif /* USE_TIMEOUT */
void     WaitForUserButtonPress(void);
void     BufferTransfer(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_USART2_UART_Init();
  /* USER CODE BEGIN 2 */
  /* Set LED2 Off */
  LED_Off();

  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* Wait for user push button press to start transfer */
    WaitForUserButtonPress();
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */

    /* transfer Tx buffer to PC application */
    BufferTransfer();
  }
  /* USER CODE END 3 */
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  LL_FLASH_SetLatency(LL_FLASH_LATENCY_2);
  while(LL_FLASH_GetLatency() != LL_FLASH_LATENCY_2)
  {
  }

  LL_PWR_SetRegulVoltageScaling(LL_PWR_REGU_VOLTAGE_SCALE1);
  LL_RCC_MSI_Enable();

   /* Wait till MSI is ready */
  while(LL_RCC_MSI_IsReady() != 1)
  {
  }

  LL_RCC_MSI_EnableRangeSelection();
  LL_RCC_MSI_SetRange(LL_RCC_MSIRANGE_11);
  LL_RCC_MSI_SetCalibTrimming(0);
  LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_MSI);

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

  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(48000000);

  /* Update CMSIS variable (which can be updated also through SystemCoreClockUpdate function) */
  LL_SetSystemCoreClock(48000000);
}

/**
  * @brief USART2 Initialization Function
  * @param None
  * @retval None
  */
static void MX_USART2_UART_Init(void)
{

  /* USER CODE BEGIN USART2_Init 0 */

  /* USER CODE END USART2_Init 0 */

  LL_USART_InitTypeDef USART_InitStruct = {0};

  LL_GPIO_InitTypeDef GPIO_InitStruct = {0};

  LL_RCC_SetUSARTClockSource(LL_RCC_USART2_CLKSOURCE_PCLK1);

  /* Peripheral clock enable */
  LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_USART2);

  LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_GPIOA);
  /**USART2 GPIO Configuration
  PA3   ------> USART2_RX
  PA2   ------> USART2_TX
  */
  GPIO_InitStruct.Pin = LL_GPIO_PIN_3|LL_GPIO_PIN_2;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_HIGH;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_UP;
  GPIO_InitStruct.Alternate = LL_GPIO_AF_7;
  LL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /* USART2 interrupt Init */
  NVIC_SetPriority(USART2_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),0, 0));
  NVIC_EnableIRQ(USART2_IRQn);

  /* USER CODE BEGIN USART2_Init 1 */

  /* USER CODE END USART2_Init 1 */
  USART_InitStruct.PrescalerValue = LL_USART_PRESCALER_DIV1;
  USART_InitStruct.BaudRate = 115200;
  USART_InitStruct.DataWidth = LL_USART_DATAWIDTH_8B;
  USART_InitStruct.StopBits = LL_USART_STOPBITS_1;
  USART_InitStruct.Parity = LL_USART_PARITY_NONE;
  USART_InitStruct.TransferDirection = LL_USART_DIRECTION_TX_RX;
  USART_InitStruct.HardwareFlowControl = LL_USART_HWCONTROL_NONE;
  USART_InitStruct.OverSampling = LL_USART_OVERSAMPLING_16;
  LL_USART_Init(USART2, &USART_InitStruct);
  LL_USART_SetTXFIFOThreshold(USART2, LL_USART_FIFOTHRESHOLD_1_8);
  LL_USART_SetRXFIFOThreshold(USART2, LL_USART_FIFOTHRESHOLD_1_8);
  LL_USART_DisableFIFO(USART2);
  LL_USART_ConfigAsyncMode(USART2);

  /* USER CODE BEGIN WKUPType USART2 */

  /* USER CODE END WKUPType USART2 */

  LL_USART_Enable(USART2);

  /* Polling USART2 initialisation */
  while((!(LL_USART_IsActiveFlag_TEACK(USART2))) || (!(LL_USART_IsActiveFlag_REACK(USART2))))
  {
  }
  /* USER CODE BEGIN USART2_Init 2 */

  /* USER CODE END USART2_Init 2 */

}

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

  /* GPIO Ports Clock Enable */
  LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_GPIOB);
  LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_GPIOA);

  /**/
  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);

  /**/
  LL_SYSCFG_SetEXTISource(LL_SYSCFG_EXTI_PORTA, LL_SYSCFG_EXTI_LINE0);

  /**/
  EXTI_InitStruct.Line_0_31 = LL_EXTI_LINE_0;
  EXTI_InitStruct.Line_32_63 = LL_EXTI_LINE_NONE;
  EXTI_InitStruct.LineCommand = ENABLE;
  EXTI_InitStruct.Mode = LL_EXTI_MODE_IT;
  EXTI_InitStruct.Trigger = LL_EXTI_TRIGGER_FALLING;
  LL_EXTI_Init(&EXTI_InitStruct);

  /**/
  LL_GPIO_SetPinPull(USER_BUTTON_GPIO_Port, USER_BUTTON_Pin, LL_GPIO_PULL_UP);

  /**/
  LL_GPIO_SetPinMode(USER_BUTTON_GPIO_Port, USER_BUTTON_Pin, LL_GPIO_MODE_INPUT);

  /* EXTI interrupt init*/
  NVIC_SetPriority(EXTI0_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),0, 0));
  NVIC_EnableIRQ(EXTI0_IRQn);

}

/* USER CODE BEGIN 4 */

/**
  * @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);
}

#if (USE_TIMEOUT == 1)
/**
  * @brief  Set LED2 to Blinking mode for an infinite loop (toggle period based on value provided as input parameter).
  * @param  Period : Period of time (in ms) between each toggling of LED
  *   This parameter can be user defined values. Pre-defined values used in that example are :
  *     @arg LED_BLINK_FAST : Fast Blinking
  *     @arg LED_BLINK_SLOW : Slow Blinking
  *     @arg LED_BLINK_ERROR : Error specific Blinking
  * @retval None
  */
void LED_Blinking(uint32_t Period)
{
  /* Toggle LED2 in an infinite loop */
  while (1)
  {
    LL_GPIO_TogglePin(LED2_GPIO_Port, LED2_Pin);
    LL_mDelay(Period);
  }
}
#endif /* USE_TIMEOUT */


/**
  * @brief  Wait for user push button press to start transfer.
  * @param  None
  * @retval None
  */
void WaitForUserButtonPress(void)
{
  while (ubButtonPress == 0)
  {
  }
  ubSend = 0;
}

/**
  * @brief  Function called for achieving TX buffer sending
  * @param  None
  * @retval None
  */
void BufferTransfer(void)
{

  /* Send characters one per one, until last char to be sent */
  while (ubSend < sizeof(aStringToSend))
  {
#if (USE_TIMEOUT == 1)
    Timeout = USART_SEND_TIMEOUT_TXE_MS;
#endif /* USE_TIMEOUT */

    /* Wait for TXE flag to be raised */
    while (!LL_USART_IsActiveFlag_TXE(USART2))
    {
#if (USE_TIMEOUT == 1)
      /* Check Systick counter flag to decrement the time-out value */
      if (LL_SYSTICK_IsActiveCounterFlag())
      {
        if (Timeout-- == 0)
        {
          /* Time-out occurred. Set LED to blinking mode */
          LED_Blinking(LED_BLINK_SLOW);
        }
      }
#endif /* USE_TIMEOUT */
    }

    /* If last char to be sent, clear TC flag */
    if (ubSend == (sizeof(aStringToSend) - 1))
    {
      LL_USART_ClearFlag_TC(USART2);
    }

    /* Write character in Transmit Data register.
       TXE flag is cleared by writing data in TDR register */
    LL_USART_TransmitData8(USART2, aStringToSend[ubSend++]);
  }

#if (USE_TIMEOUT == 1)
  Timeout = USART_SEND_TIMEOUT_TC_MS;
#endif /* USE_TIMEOUT */

  /* Wait for TC flag to be raised for last char */
  while (!LL_USART_IsActiveFlag_TC(USART2))
  {
#if (USE_TIMEOUT == 1)
    /* Check Systick counter flag to decrement the time-out value */
    if (LL_SYSTICK_IsActiveCounterFlag())
    {
      if (Timeout-- == 0)
      {
        /* Time-out occurred. Set LED to blinking mode */
        LED_Blinking(LED_BLINK_SLOW);
      }
    }
#endif /* USE_TIMEOUT */
  }

  ubButtonPress = 0;

  /* Turn LED2 On at end of transfer : Tx sequence completed successfully */
  LED_On();
}


/******************************************************************************/
/*   USER IRQ HANDLER TREATMENT Functions                                     */
/******************************************************************************/
/**
  * @brief  Function to manage User push-button (B1)
  * @param  None
  * @retval None
  */
void UserButton_Callback(void)
{
  /* Update button press variable : to be checked in waiting loop in main program */
  ubButtonPress = 1;
}


/* 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,
     tex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
