/**
  ******************************************************************************
  * @file    I2C/I2C_TwoBoards_AdvComIT/Src/main.c
  * @author  MCD Application Team
  * @brief   This sample code shows how to use STM32F3xx I2C HAL API to transmit
  *          and receive a data buffer with a communication process based on
  *          IT transfer.
  *          The communication is done using 2 Boards.
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2016 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under BSD 3-Clause license,
  * the "License"; You may not use this file except in compliance with the
  * License. You may obtain a copy of the License at:
  *                        opensource.org/licenses/BSD-3-Clause
  *
  ******************************************************************************
  */

/* Includes ------------------------------------------------------------------*/
#include "main.h"

/** @addtogroup STM32F3xx_HAL_Examples
  * @{
  */

/** @addtogroup I2C_TwoBoards_AdvComIT
  * @{
  */

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Uncomment this line to use the board as master, if not it is used as slave */
//#define MASTER_BOARD
#define I2C_ADDRESS        0x3E
#define MASTER_REQ_READ    0x12
#define MASTER_REQ_WRITE   0x34

/* I2C TIMING Register define when I2C clock source is SYSCLK */
/* I2C TIMING is calculated in case of the I2C Clock source is the SYSCLK = 64 MHz */
/* This example use TIMING to 0x00400B27 to reach 1 MHz speed (Rise time = 26ns, Fall time = 2ns) */
#define I2C_TIMING      0x00400B27

/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* I2C handler declaration */
I2C_HandleTypeDef I2cHandle;


/* Buffer used for transmission */
uint8_t aTxBuffer[] = " ****I2C_TwoBoards communication based on IT****  ****I2C_TwoBoards communication based on IT****  ****I2C_TwoBoards communication based on IT**** ";

/* Buffer used for reception */
uint8_t aRxBuffer[RXBUFFERSIZE];
uint16_t hTxNumData = 0, hRxNumData = 0;
uint8_t bTransferRequest = 0;

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static uint16_t Buffercmp(uint8_t *pBuffer1, uint8_t *pBuffer2, uint16_t BufferLength);
static void Flush_Buffer(uint8_t* pBuffer, uint16_t BufferLength);
static void Error_Handler(void);

/* Private functions ---------------------------------------------------------*/

/**
  * @brief  Main program
  * @param  None
  * @retval None
  */
int main(void)
{

  /* STM32F3xx HAL library initialization:
       - Configure the Flash prefetch
       - Configure the Systick to generate an interrupt each 1 msec
       - Set NVIC Group Priority to 4
       - Low Level Initialization
     */
  HAL_Init();
  
  /* Configure the system clock to 64 MHz */
  SystemClock_Config();

  /* Configure LED1 and LED3 */
  BSP_LED_Init(LED1);
  BSP_LED_Init(LED3);
  

  /*##-1- Configure the I2C peripheral ######################################*/
  I2cHandle.Instance             = I2Cx;
  I2cHandle.Init.Timing          = I2C_TIMING;
  I2cHandle.Init.OwnAddress1     = I2C_ADDRESS;
  I2cHandle.Init.AddressingMode  = I2C_ADDRESSINGMODE_7BIT;
  I2cHandle.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
  I2cHandle.Init.OwnAddress2     = 0xFF;
  I2cHandle.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
  I2cHandle.Init.NoStretchMode   = I2C_NOSTRETCH_DISABLE;  
  
  if(HAL_I2C_Init(&I2cHandle) != HAL_OK)
  {
    /* Initialization Error */
    Error_Handler();
  }
  
  /* Enable the Analog I2C Filter */
  HAL_I2CEx_ConfigAnalogFilter(&I2cHandle,I2C_ANALOGFILTER_ENABLE);

#ifdef MASTER_BOARD
  
  /* Configure User push-button button */
  BSP_PB_Init(BUTTON_USER,BUTTON_MODE_GPIO);

  /* Wait for User push-button press before starting the Communication */
  while (BSP_PB_GetState(BUTTON_USER) != GPIO_PIN_SET)
  {
  }
  
  /* Wait for User push-button release before starting the Communication */
  while (BSP_PB_GetState(BUTTON_USER) != GPIO_PIN_RESET)
  {
  }

  while(1)
  {
    /* Initialize number of data variables */
    hTxNumData = TXBUFFERSIZE;
    hRxNumData = RXBUFFERSIZE;

    /* Update bTransferRequest to send buffer write request for Slave */
    bTransferRequest = MASTER_REQ_WRITE;

    /*##-2- Master sends write request for slave #############################*/
    while(HAL_I2C_Master_Transmit_IT(&I2cHandle, (uint16_t)I2C_ADDRESS, (uint8_t*)&bTransferRequest, 1)!= HAL_OK)
    {
      /* Error_Handler() function is called when Timeout error occurs.
         When Acknowledge failure occurs (Slave don't acknowledge its address)
         Master restarts communication */
      if (HAL_I2C_GetError(&I2cHandle) != HAL_I2C_ERROR_AF)
      {
        Error_Handler();
      }
    }

    /*  Before starting a new communication transfer, you need to check the current
    state of the peripheral; if it’s busy you need to wait for the end of current
    transfer before starting a new one.
    For simplicity reasons, this example is just waiting till the end of the
    transfer, but application may perform other tasks while transfer operation
    is ongoing. */
    while (HAL_I2C_GetState(&I2cHandle) != HAL_I2C_STATE_READY)
    {
    }

    /*##-3- Master sends number of data to be written ########################*/
    while(HAL_I2C_Master_Transmit_IT(&I2cHandle, (uint16_t)I2C_ADDRESS, (uint8_t*)&hTxNumData, 2)!= HAL_OK)
    {
      /* Error_Handler() function is called when Timeout error occurs.
         When Acknowledge failure occurs (Slave don't acknowledge its address)
         Master restarts communication */
      if (HAL_I2C_GetError(&I2cHandle) != HAL_I2C_ERROR_AF)
      {
        Error_Handler();
      }
    }

    /*  Before starting a new communication transfer, you need to check the current
    state of the peripheral; if it’s busy you need to wait for the end of current
    transfer before starting a new one.
    For simplicity reasons, this example is just waiting till the end of the
    transfer, but application may perform other tasks while transfer operation
    is ongoing. */
    while (HAL_I2C_GetState(&I2cHandle) != HAL_I2C_STATE_READY)
    {
    }

    /*##-4- Master sends aTxBuffer to slave ##################################*/
    while(HAL_I2C_Master_Transmit_IT(&I2cHandle, (uint16_t)I2C_ADDRESS, (uint8_t*)aTxBuffer, TXBUFFERSIZE)!= HAL_OK)
    {
      /* Error_Handler() function is called when Timeout error occurs.
         When Acknowledge failure occurs (Slave don't acknowledge its address)
         Master restarts communication */
      if (HAL_I2C_GetError(&I2cHandle) != HAL_I2C_ERROR_AF)
      {
        Error_Handler();
      }
    }

    /*  Before starting a new communication transfer, you need to check the current
    state of the peripheral; if it’s busy you need to wait for the end of current
    transfer before starting a new one.
    For simplicity reasons, this example is just waiting till the end of the
    transfer, but application may perform other tasks while transfer operation
    is ongoing. */
    while (HAL_I2C_GetState(&I2cHandle) != HAL_I2C_STATE_READY)
    {
    }

    /* Update bTransferRequest to send buffer read request for Slave */
    bTransferRequest = MASTER_REQ_READ;

    /*##-5- Master sends read request for slave ##############################*/
    while(HAL_I2C_Master_Transmit_IT(&I2cHandle, (uint16_t)I2C_ADDRESS, (uint8_t*)&bTransferRequest, 1)!= HAL_OK)
    {
      /* Error_Handler() function is called when Timeout error occurs.
         When Acknowledge failure occurs (Slave don't acknowledge its address)
         Master restarts communication */
      if (HAL_I2C_GetError(&I2cHandle) != HAL_I2C_ERROR_AF)
      {
        Error_Handler();
      }
    }

    /*  Before starting a new communication transfer, you need to check the current
    state of the peripheral; if it’s busy you need to wait for the end of current
    transfer before starting a new one.
    For simplicity reasons, this example is just waiting till the end of the
    transfer, but application may perform other tasks while transfer operation
    is ongoing. */
    while (HAL_I2C_GetState(&I2cHandle) != HAL_I2C_STATE_READY)
    {
    }

    /*##-6- Master sends number of data to be read ###########################*/
    while(HAL_I2C_Master_Transmit_IT(&I2cHandle, (uint16_t)I2C_ADDRESS, (uint8_t*)&hRxNumData, 2)!= HAL_OK)
    {
      /* Error_Handler() function is called when Timeout error occurs.
         When Acknowledge failure occurs (Slave don't acknowledge its address)
         Master restarts communication */
      if (HAL_I2C_GetError(&I2cHandle) != HAL_I2C_ERROR_AF)
      {
        Error_Handler();
      }
    }

    /*  Before starting a new communication transfer, you need to check the current
    state of the peripheral; if it’s busy you need to wait for the end of current
    transfer before starting a new one.
    For simplicity reasons, this example is just waiting till the end of the
    transfer, but application may perform other tasks while transfer operation
    is ongoing. */
    while (HAL_I2C_GetState(&I2cHandle) != HAL_I2C_STATE_READY)
    {
    }

    /*##-7- Master receives aRxBuffer from slave #############################*/
    while(HAL_I2C_Master_Receive_IT(&I2cHandle, (uint16_t)I2C_ADDRESS, (uint8_t*)aRxBuffer, RXBUFFERSIZE)!= HAL_OK)
    {
      /* Error_Handler() function is called when Timeout error occurs.
         When Acknowledge failure occurs (Slave don't acknowledge its address)
         Master restarts communication */
      if (HAL_I2C_GetError(&I2cHandle) != HAL_I2C_ERROR_AF)
      {
        Error_Handler();
      }
    }

    /*  Before starting a new communication transfer, you need to check the current
    state of the peripheral; if it’s busy you need to wait for the end of current
    transfer before starting a new one.
    For simplicity reasons, this example is just waiting till the end of the
    transfer, but application may perform other tasks while transfer operation
    is ongoing. */
    while (HAL_I2C_GetState(&I2cHandle) != HAL_I2C_STATE_READY)
    {
    }
    /* Check correctness of received buffer ##################################*/
    if(Buffercmp((uint8_t*)aTxBuffer,(uint8_t*)aRxBuffer,hRxNumData))
    {
      /* Processing Error */
      Error_Handler();
    }

    /* Flush Rx buffers */
    Flush_Buffer((uint8_t*)aRxBuffer,RXBUFFERSIZE);

    /* Toggle LED1 */
    BSP_LED_Toggle(LED1);

    /* This delay permits to see LED1 toggling */
    HAL_Delay(25);
  }
#else
  while(1)
  {
    /* Initialize number of data variables */
    hTxNumData = 0;
    hRxNumData = 0;

    /*##-2- Slave receive request from master ################################*/
    while(HAL_I2C_Slave_Receive_IT(&I2cHandle, (uint8_t*)&bTransferRequest, 1)!= HAL_OK)
    {
    }

    /*  Before starting a new communication transfer, you need to check the current
    state of the peripheral; if it’s busy you need to wait for the end of current
    transfer before starting a new one.
    For simplicity reasons, this example is just waiting till the end of the
    transfer, but application may perform other tasks while transfer operation
    is ongoing. */
    while (HAL_I2C_GetState(&I2cHandle) != HAL_I2C_STATE_READY)
    {
    }

    /* If master request write operation #####################################*/
    if (bTransferRequest == MASTER_REQ_WRITE)
    {
      /*##-3- Slave receive number of data to be read ########################*/
      while(HAL_I2C_Slave_Receive_IT(&I2cHandle, (uint8_t*)&hRxNumData, 2)!= HAL_OK);

      /*  Before starting a new communication transfer, you need to check the current
      state of the peripheral; if it’s busy you need to wait for the end of current
      transfer before starting a new one.
      For simplicity reasons, this example is just waiting till the end of the
      transfer, but application may perform other tasks while transfer operation
      is ongoing. */
      while (HAL_I2C_GetState(&I2cHandle) != HAL_I2C_STATE_READY)
      {
      }

      /*##-4- Slave receives aRxBuffer from master ###########################*/
      while(HAL_I2C_Slave_Receive_IT(&I2cHandle, (uint8_t*)aRxBuffer, hRxNumData)!= HAL_OK);

      /*  Before starting a new communication transfer, you need to check the current
      state of the peripheral; if it’s busy you need to wait for the end of current
      transfer before starting a new one.
      For simplicity reasons, this example is just waiting till the end of the
      transfer, but application may perform other tasks while transfer operation
      is ongoing. */
      while (HAL_I2C_GetState(&I2cHandle) != HAL_I2C_STATE_READY)
      {
      }

      /* Check correctness of received buffer ################################*/
      if(Buffercmp((uint8_t*)aTxBuffer,(uint8_t*)aRxBuffer,hRxNumData))
      {
        /* Processing Error */
        Error_Handler();
      }

      /* Flush Rx buffers */
      Flush_Buffer((uint8_t*)aRxBuffer,RXBUFFERSIZE);

      /* Toggle LED1 */
      BSP_LED_Toggle(LED1);
    }
    /* If master request write operation #####################################*/
    else
    {
      /*##-3- Slave receive number of data to be written #####################*/
      while(HAL_I2C_Slave_Receive_IT(&I2cHandle, (uint8_t*)&hTxNumData, 2)!= HAL_OK);

      /*  Before starting a new communication transfer, you need to check the current
      state of the peripheral; if it’s busy you need to wait for the end of current
      transfer before starting a new one.
      For simplicity reasons, this example is just waiting till the end of the
      transfer, but application may perform other tasks while transfer operation
      is ongoing. */
      while (HAL_I2C_GetState(&I2cHandle) != HAL_I2C_STATE_READY)
      {
      }

      /*##-4- Slave transmit aTxBuffer to master #############################*/
      while(HAL_I2C_Slave_Transmit_IT(&I2cHandle, (uint8_t*)aTxBuffer, RXBUFFERSIZE)!= HAL_OK);

      /*  Before starting a new communication transfer, you need to check the current
      state of the peripheral; if it’s busy you need to wait for the end of current
      transfer before starting a new one.
      For simplicity reasons, this example is just waiting till the end of the
      transfer, but application may perform other tasks while transfer operation
      is ongoing. */
      while (HAL_I2C_GetState(&I2cHandle) != HAL_I2C_STATE_READY)
      {
      }
    }
  }
#endif /* MASTER_BOARD */
}

/**
  * @brief  System Clock Configuration
  *         The system Clock is configured as follow : 
  *            System Clock source            = PLL (HSI)
  *            SYSCLK(Hz)                     = 64000000
  *            HCLK(Hz)                       = 64000000
  *            AHB Prescaler                  = 1
  *            APB1 Prescaler                 = 2
  *            APB2 Prescaler                 = 1
  *            HSI Frequency(Hz)              = 8000000
  *            PREDIV                         = RCC_PREDIV_DIV2 (2)
  *            PLLMUL                         = RCC_PLL_MUL16 (16)
  *            Flash Latency(WS)              = 2
  * @param  None
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  RCC_OscInitTypeDef RCC_OscInitStruct;
  
  /* HSI Oscillator already ON after system reset, activate PLL with HSI as source */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_NONE;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
  RCC_OscInitStruct.PLL.PREDIV = RCC_PREDIV_DIV2;
  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL16;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct)!= HAL_OK)
  {
    /* Initialization Error */
    while(1); 
  }

  /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 
     clocks dividers */
  RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | 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;
  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2)!= HAL_OK)
  {
    /* Initialization Error */
    while(1); 
  }
}
/**
  * @brief  I2C error callbacks.
  * @param  I2cHandle: I2C handle
  * @note   This example shows a simple way to report transfer error, and you can
  *         add your own implementation.
  * @retval None
  */
void HAL_I2C_ErrorCallback(I2C_HandleTypeDef *I2cHandle)
{
  /** 1- When Slave don't acknowledge it's address, Master restarts communication.
    * 2- When Master don't acknowledge the last data transferred, Slave don't care in this example.
    */
  if (HAL_I2C_GetError(I2cHandle) != HAL_I2C_ERROR_AF)
  {
    /* Turn Off LED1 */
    BSP_LED_Off(LED1);
    /* Turn On LED3 */
    BSP_LED_On(LED3);
  }
}

/**
  * @brief  This function is executed in case of error occurrence.
  * @param  None
  * @retval None
  */
static void Error_Handler(void)
{
  /* Turn LED3 on */
  BSP_LED_On(LED3);
  while(1)
  {
  }
}

/**
  * @brief  Compares two buffers.
  * @param  pBuffer1, pBuffer2: buffers to be compared.
  * @param  BufferLength: buffer's length
  * @retval 0  : pBuffer1 identical to pBuffer2
  *         >0 : pBuffer1 differs from pBuffer2
  */
static uint16_t Buffercmp(uint8_t* pBuffer1, uint8_t* pBuffer2, uint16_t BufferLength)
{
  while (BufferLength--)
  {
    if ((*pBuffer1) != *pBuffer2)
    {
      return BufferLength;
    }
    pBuffer1++;
    pBuffer2++;
  }

  return 0;
}

/**
  * @brief  Flushes the buffer
  * @param  pBuffer: buffers to be flushed.
  * @param  BufferLength: buffer's length
  * @retval None
  */
static void Flush_Buffer(uint8_t* pBuffer, uint16_t BufferLength)
{
  while (BufferLength--)
  {
    *pBuffer = 0;

    pBuffer++;
  }
}
#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 can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */

  /* Infinite loop */
  while (1)
  {
  }
}
#endif


/**
  * @}
  */

/**
  * @}
  */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
