/**
  ******************************************************************************
  * @file    SPI/SPI_FullDuplex_AdvComIT/Src/main.c
  * @author  MCD Application Team
  * @brief   This sample code shows how to use STM32F3xx SPI HAL API to transmit
  *          and receive a data buffer with a communication process based on
  *          Interrupt 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 SPI_FullDuplex_AdvComIT
  * @{
  */ 

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
#define SPI_ACK_BYTES             0xA5A5
#define SPI_NACK_BYTES            0xDEAD
#define SPI_TIMEOUT_MAX           0x1000
#define SPI_SLAVE_SYNBYTE         0x53
#define SPI_MASTER_SYNBYTE        0xAC

/* Defines used for transfer communication */
#define ADDRCMD_MASTER_READ                         ((uint16_t)0x1234)
#define ADDRCMD_MASTER_WRITE                        ((uint16_t)0x5678)
#define CMD_LENGTH                                  ((uint16_t)0x0004)
#define DATA_LENGTH                                 ((uint16_t)0x0020)          

/* Private macro -------------------------------------------------------------*/
/* Uncomment this line to use the board as master, if not it is used as slave */
#define MASTER_BOARD

/* Private variables ---------------------------------------------------------*/
/* SPI handler declaration */
SPI_HandleTypeDef SpiHandle;

/* Buffer used for transmission */
uint8_t aTxMasterBuffer[] = "SPI - MASTER - Transmit message";
uint8_t aTxSlaveBuffer[]  = "SPI - SLAVE - Transmit message ";

/* Buffer used for reception */
uint8_t aRxBuffer[DATA_LENGTH];

/* Private function prototypes -----------------------------------------------*/
#ifdef MASTER_BOARD
static void Master_Synchro(void);
#else
static void Slave_Synchro(void);
#endif
void SystemClock_Config(void);
static void Error_Handler(void);
static uint16_t Buffercmp(uint8_t *pBuffer1, uint8_t *pBuffer2, uint16_t BufferLength);
static void Flush_Buffer(uint8_t* pBuffer, uint16_t BufferLength);

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

/**
  * @brief  Main program.
  * @param  None
  * @retval None
  */
int main(void)
{
#ifndef MASTER_BOARD
  uint16_t addrcmd = 0;
  uint16_t comlength = 0;
#endif
  uint8_t paddrcmd[CMD_LENGTH] = {0};
  __IO uint16_t ackbytes = 0x0000;

  /* STM32F3xx HAL library initialization:
       - Configure the Flash prefetch
       - Systick timer is configured by default as source of time base, but user 
         can eventually implement his proper time base source (a general purpose 
         timer for example or other time source), keeping in mind that Time base 
         duration should be kept 1ms since PPP_TIMEOUT_VALUEs are defined and 
         handled in milliseconds basis.
       - Set NVIC Group Priority to 4
       - Low Level Initialization
     */
  HAL_Init();
  
  /* Configure the system clock to 64 MHz */
  SystemClock_Config();

  /* Configure LED2 */
  BSP_LED_Init(LED2);

  /*##-1- Configure the SPI peripheral #######################################*/
  /* Set the SPI parameters */
  SpiHandle.Instance               = SPIx;
  SpiHandle.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_16;
  SpiHandle.Init.Direction         = SPI_DIRECTION_2LINES;
  SpiHandle.Init.CLKPhase          = SPI_PHASE_1EDGE;
  SpiHandle.Init.CLKPolarity       = SPI_POLARITY_LOW;
  SpiHandle.Init.DataSize          = SPI_DATASIZE_8BIT;
  SpiHandle.Init.FirstBit          = SPI_FIRSTBIT_MSB;
  SpiHandle.Init.TIMode            = SPI_TIMODE_DISABLE;
  SpiHandle.Init.CRCCalculation    = SPI_CRCCALCULATION_DISABLE;
  SpiHandle.Init.CRCPolynomial     = 7;
  SpiHandle.Init.CRCLength         = SPI_CRC_LENGTH_8BIT;
  SpiHandle.Init.NSS               = SPI_NSS_SOFT;
  SpiHandle.Init.NSSPMode          = SPI_NSS_PULSE_DISABLE;

#ifdef MASTER_BOARD
  SpiHandle.Init.Mode = SPI_MODE_MASTER;
#else
  SpiHandle.Init.Mode = SPI_MODE_SLAVE;
#endif /* MASTER_BOARD */

  if(HAL_SPI_Init(&SpiHandle) != HAL_OK)
  {
    /* Initialization Error */
    Error_Handler();
  }

#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_RESET)
  {
    BSP_LED_Toggle(LED2);
    HAL_Delay(50);
  }
  BSP_LED_Off(LED2);
#endif /* MASTER_BOARD */

  /* Infinite loop */  
  while(1)
  {
#ifdef MASTER_BOARD
    /* Synchronization between Master and Slave */
    Master_Synchro();
    
    /* Receive Data from the Slave ###########################################*/ 
    paddrcmd[0] = (uint8_t) (ADDRCMD_MASTER_READ >> 8);
    paddrcmd[1] = (uint8_t) ADDRCMD_MASTER_READ;
    paddrcmd[2] = (uint8_t) (DATA_LENGTH >> 8);
    paddrcmd[3] = (uint8_t) DATA_LENGTH;
    /* Send Master READ command to slave */
    if(HAL_SPI_Transmit_IT(&SpiHandle, paddrcmd, CMD_LENGTH) != HAL_OK)
    {
      Error_Handler();
    }
    /*  Before starting a new communication transfer, you need to check the current
        state of the peripheral; if itâ€™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_SPI_GetState(&SpiHandle) != HAL_SPI_STATE_READY)
    {}
    
    /* Synchronization between Master and Slave */
    Master_Synchro();
    
    /* Receive ACK from the Slave */
    ackbytes = 0;
    if(HAL_SPI_Receive_IT(&SpiHandle, (uint8_t *)&ackbytes, sizeof(ackbytes)) != HAL_OK)
    {
      Error_Handler();
    }
    while(HAL_SPI_GetState(&SpiHandle) != HAL_SPI_STATE_READY)
    {}

    /* Check the received ACK */
    if(ackbytes == SPI_ACK_BYTES)
    {
      /* Synchronization between Master and Slave */
      Master_Synchro();
      
      /* Receive the requested data from the slave */
      if(HAL_SPI_Receive_IT(&SpiHandle, aRxBuffer, DATA_LENGTH) != HAL_OK)
      {
        Error_Handler();
      }
      while(HAL_SPI_GetState(&SpiHandle) != HAL_SPI_STATE_READY)
      {}
    
      /* Synchronization between Master and Slave */
      Master_Synchro();
      
      /* Send ACK to the Slave */
      ackbytes = SPI_ACK_BYTES;
      if(HAL_SPI_Transmit_IT(&SpiHandle, (uint8_t *)&ackbytes, sizeof(ackbytes)) != HAL_OK)
      {
        Error_Handler();
      }
      while(HAL_SPI_GetState(&SpiHandle) != HAL_SPI_STATE_READY)
      {}
    }    
    else
    {
      /* Transfer error in transmission process */
      Error_Handler();
    }
    
    /* Compare received buffer with one expected from slave */
    if(Buffercmp((uint8_t*)aTxSlaveBuffer, (uint8_t*)aRxBuffer, DATA_LENGTH))
    {
      /* Transfer error in transmission process */
      Error_Handler();
    }
    else
    {
      /* Turn LED2 on: Reception is correct */
      BSP_LED_Toggle(LED2);
    }
    
    /* Synchronization between Master and Slave */
    Master_Synchro();
    
    /* Transmit Data To Slave ################################################*/
    paddrcmd[0] = (uint8_t) (ADDRCMD_MASTER_WRITE >> 8);
    paddrcmd[1] = (uint8_t) ADDRCMD_MASTER_WRITE;
    paddrcmd[2] = (uint8_t) (DATA_LENGTH >> 8);
    paddrcmd[3] = (uint8_t) DATA_LENGTH;
    /* Send Master WRITE command to the slave */
    if(HAL_SPI_Transmit_IT(&SpiHandle, paddrcmd, CMD_LENGTH) != HAL_OK)
    {
      Error_Handler();
    }
    while(HAL_SPI_GetState(&SpiHandle) != HAL_SPI_STATE_READY)
    {}
  
    /* Synchronization between Master and Slave */
    Master_Synchro();
    
    /* Receive ACK from the Slave */
    ackbytes = 0;
    if(HAL_SPI_Receive_IT(&SpiHandle, (uint8_t *)&ackbytes, sizeof(ackbytes)) != HAL_OK)
    {
      Error_Handler();
    }
    while(HAL_SPI_GetState(&SpiHandle) != HAL_SPI_STATE_READY)
    {}
  
    /* Check the received ACK */
    if(ackbytes == SPI_ACK_BYTES)
    {
      /* Synchronization between Master and Slave */
      Master_Synchro();
      /* Send the requested data from the slave */
      if(HAL_SPI_Transmit_IT(&SpiHandle, aTxMasterBuffer, DATA_LENGTH) != HAL_OK)
      {
        Error_Handler();
      }
      while(HAL_SPI_GetState(&SpiHandle) != HAL_SPI_STATE_READY)
      {}
    
      /* Synchronization between Master and Slave */
      Master_Synchro();
      
      /* Receive ACK from the Slave */
      ackbytes = 0;
      if(HAL_SPI_Receive_IT(&SpiHandle, (uint8_t *)&ackbytes, sizeof(ackbytes)) != HAL_OK)
      {
        Error_Handler();
      }
      while(HAL_SPI_GetState(&SpiHandle) != HAL_SPI_STATE_READY)
      {}
     }    
    else
    {
      /* Transfer error in transmission process */
      Error_Handler();
    }
   
    /* Flush Rx buffer for next transmission */
    Flush_Buffer(aRxBuffer, DATA_LENGTH);
    
    /* Toggle LED2 */
    BSP_LED_Toggle(LED2);
    /* This delay permit to user to see LED2 toggling*/
    HAL_Delay(100);
#else
    /* Synchronization between Master and Slave */
    Slave_Synchro();

    /* Receive command from Master */
    if(HAL_SPI_Receive_IT(&SpiHandle, paddrcmd, CMD_LENGTH) != HAL_OK)
    {
      Error_Handler();
    }
    while (HAL_SPI_GetState(&SpiHandle) != HAL_SPI_STATE_READY)
    {}

    /* Compute command and required data length */
    addrcmd = (uint16_t) ((paddrcmd[0] << 8) | paddrcmd[1]);
    comlength = (uint16_t) ((paddrcmd[2] << 8) | paddrcmd[3]);

    /* Check if received command correct */
    if(((addrcmd == ADDRCMD_MASTER_READ) || (addrcmd == ADDRCMD_MASTER_WRITE)) && (comlength > 0))
    {
      /* Synchronization between Master and Slave */
      Slave_Synchro();

      /* Send acknowledge to Master */
      ackbytes = SPI_ACK_BYTES;
      if(HAL_SPI_Transmit_IT(&SpiHandle, (uint8_t *)&ackbytes, sizeof(ackbytes)) != HAL_OK)
      {
        Error_Handler();
      }
      while (HAL_SPI_GetState(&SpiHandle) != HAL_SPI_STATE_READY)
      {}

      /* Check if Master requiring data read or write */
      if(addrcmd == ADDRCMD_MASTER_READ)
      {
        /* Synchronization between Master and Slave */
        Slave_Synchro();

        /* Send data to Master */
        if(HAL_SPI_Transmit_IT(&SpiHandle, aTxSlaveBuffer, DATA_LENGTH) != HAL_OK)
        {
          Error_Handler();
        }
        while (HAL_SPI_GetState(&SpiHandle) != HAL_SPI_STATE_READY)
        {}

        /* Synchronization between Master and Slave */
        Slave_Synchro();

        /* Receive acknowledgement from Master */
        ackbytes = 0;
        if(HAL_SPI_Receive_IT(&SpiHandle, (uint8_t *)&ackbytes, sizeof(ackbytes)) != HAL_OK)
        {
          Error_Handler();
        }
        while (HAL_SPI_GetState(&SpiHandle) != HAL_SPI_STATE_READY)
        {}

        /* Check acknowledgement */
        if(ackbytes !=  SPI_ACK_BYTES)
        {
          Error_Handler();
        }
      }
      else if(addrcmd == ADDRCMD_MASTER_WRITE)
      {
        /* Synchronization between Master and Slave */
        Slave_Synchro();

        /* Receive data from Master */
        if(HAL_SPI_Receive_IT(&SpiHandle, aRxBuffer, DATA_LENGTH) != HAL_OK)
        {
          Error_Handler();
        }
        while (HAL_SPI_GetState(&SpiHandle) != HAL_SPI_STATE_READY)
        {}

        /* Synchronization between Master and Slave */
        Slave_Synchro();

        /* Send acknowledgement to Master */
        ackbytes = SPI_ACK_BYTES;
        if(HAL_SPI_Transmit_IT(&SpiHandle, (uint8_t *)&ackbytes, sizeof(ackbytes)) != HAL_OK)
        {
          Error_Handler();
        }
        while (HAL_SPI_GetState(&SpiHandle) != HAL_SPI_STATE_READY)
        {}

        /* In case, Master has sent data, compare received buffer with one expected */
        if(Buffercmp((uint8_t*)aTxMasterBuffer, (uint8_t*)aRxBuffer, DATA_LENGTH))
        {
          /* Transfer error in transmission process */
          Error_Handler();
        }
        else
        {
          /* Toggle LED2 on: Reception is correct */
          BSP_LED_Toggle(LED2);
        }
      }
    }
    else
    {
      /* Synchronization between Master and Slave */
      Slave_Synchro();
      
      /* Send acknowledgement to Master */
      ackbytes = SPI_NACK_BYTES;
      if(HAL_SPI_Transmit_IT(&SpiHandle, (uint8_t *)&ackbytes, sizeof(ackbytes)) != HAL_OK)
      {
        Error_Handler();
      }
      while (HAL_SPI_GetState(&SpiHandle) != HAL_SPI_STATE_READY)
      {}

      Error_Handler();
    }

    /* Flush Rx buffer for next transmission */
    Flush_Buffer(aRxBuffer, DATA_LENGTH);
#endif
  }
}

#ifdef MASTER_BOARD
/**
  * @brief  Master Synchronization with Slave.
  * @param  None
  * @retval None
  */
static void Master_Synchro(void)
{
  uint8_t txackbytes = SPI_MASTER_SYNBYTE, rxackbytes = 0x00;
  do
  {
    HAL_Delay(20);
    /* Call SPI write function to send command to slave */
    if(HAL_SPI_TransmitReceive_IT(&SpiHandle, (uint8_t *)&txackbytes, (uint8_t *)&rxackbytes, 1) != HAL_OK)
    {
      Error_Handler();
    }
    while(HAL_SPI_GetState(&SpiHandle) != HAL_SPI_STATE_READY)
    {}
  }while(rxackbytes != SPI_SLAVE_SYNBYTE);
}
#else
/**
  * @brief  Slave synchronization with Master
  * @param  None
  * @retval None
  */
static void Slave_Synchro(void)
{
  uint8_t txackbyte = SPI_SLAVE_SYNBYTE, rxackbyte = 0x00;

  do
  {
    if (HAL_SPI_TransmitReceive_IT(&SpiHandle, (uint8_t *)&txackbyte, (uint8_t *)&rxackbyte, 1) != HAL_OK)
    {
      Error_Handler();
    }
    while (HAL_SPI_GetState(&SpiHandle) != HAL_SPI_STATE_READY)
    {}
  }
  while (rxackbyte != SPI_MASTER_SYNBYTE);
}
#endif

/**
  * @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
  *            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.PLLMUL = RCC_PLL_MUL16;
  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  SPI error callbacks.
  * @param  hspi: SPI handle
  * @note   This example shows a simple way to report transfer error, and you can
  *         add your own implementation.
  * @retval None
  */
void HAL_SPI_ErrorCallback(SPI_HandleTypeDef *hspi)
{
  /* call error handler */
  Error_Handler();
}

/**
  * @brief  This function is executed in case of error occurrence.
  * @param  None
  * @retval None
  */
static void Error_Handler(void)
{
  /* Turn LED2 on */
  BSP_LED_On(LED2);
  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****/
