/**
  ******************************************************************************
  * @file    SPI/SPI_FullDuplex_AdvComPolling/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
  *          Polling 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_AdvComPolling
  * @{
  */ 

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
enum {
  TRANSFER_WAIT,
  TRANSFER_COMPLETE,
  TRANSFER_ERROR
};

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

/* transfer state */
__IO uint32_t wTransferState = TRANSFER_WAIT;

/* 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};
  uint16_t ackbytes = 0x0000;

  /* 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, LED2 and LED3 */
  BSP_LED_Init(LED1);
  BSP_LED_Init(LED2);
  BSP_LED_Init(LED3);

  /*##-1- Configure the SPI peripheral #######################################*/
  /* Set the SPI parameters */
  SpiHandle.Instance               = SPIx;
  SpiHandle.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_256;
  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_SET)
  {
    BSP_LED_Toggle(LED1);
    HAL_Delay(50);
  }
  BSP_LED_Off(LED1);
#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_TransmitReceive(&SpiHandle, paddrcmd, (uint8_t *)aDummyBuffer, CMD_LENGTH, SPI_TIMEOUT_MAX) != HAL_OK)
    {
      Error_Handler();
    }
    
    /* Synchronization between Master and Slave */
    Master_Synchro();
    
    /* Receive ACK from the Slave */
    ackbytes = 0;
    if(HAL_SPI_TransmitReceive(&SpiHandle, (uint8_t *)aDummyBuffer, (uint8_t *)&ackbytes, sizeof(ackbytes), SPI_TIMEOUT_MAX) != HAL_OK)
    {
      Error_Handler();
    }
    /* 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_TransmitReceive(&SpiHandle, (uint8_t *)aDummyBuffer, aRxBuffer, DATA_LENGTH, SPI_TIMEOUT_MAX) != HAL_OK)
      {
        Error_Handler();
      }
      /* Synchronization between Master and Slave */
      Master_Synchro();
      
      /* Send ACK to the Slave */
      ackbytes = SPI_ACK_BYTES;
      if(HAL_SPI_TransmitReceive(&SpiHandle, (uint8_t *)&ackbytes, (uint8_t *)aDummyBuffer, sizeof(ackbytes), SPI_TIMEOUT_MAX) != HAL_OK)
      {
        Error_Handler();
      }
    }    
    else
    {
      /* Transfer error in transmission process */
      Error_Handler();
    }
    
    /* Compare received buffer with one expected from slave */
    if(Buffercmp((uint8_t*)aTxSlaveBuffer, (uint8_t*)aRxBuffer, CMD_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_TransmitReceive(&SpiHandle, paddrcmd, (uint8_t *)aDummyBuffer, CMD_LENGTH, SPI_TIMEOUT_MAX) != HAL_OK)
    {
      Error_Handler();
    }
    /* Synchronization between Master and Slave */
    Master_Synchro();
    
    /* Receive ACK from the Slave */
    ackbytes = 0;
    if(HAL_SPI_TransmitReceive(&SpiHandle, (uint8_t *)aDummyBuffer, (uint8_t *)&ackbytes, sizeof(ackbytes), SPI_TIMEOUT_MAX) != HAL_OK)
    {
      Error_Handler();
    }
    /* 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_TransmitReceive(&SpiHandle, aTxMasterBuffer, (uint8_t *)aDummyBuffer, DATA_LENGTH, SPI_TIMEOUT_MAX) != HAL_OK)
      {
        Error_Handler();
      }
      /* Synchronization between Master and Slave */
      Master_Synchro();
      
      /* Receive ACK from the Slave */
      ackbytes = 0;
      if(HAL_SPI_TransmitReceive(&SpiHandle, (uint8_t *)aDummyBuffer, (uint8_t *)&ackbytes, sizeof(ackbytes), SPI_TIMEOUT_MAX) != HAL_OK)
      {
        Error_Handler();
      }
    }    
    else
    {
      /* Transfer error in transmission process */
      Error_Handler();
    }
   
    /* Flush Rx buffer for next transmission */
    Flush_Buffer(aRxBuffer, DATA_LENGTH);
    
    /* Toggle LED1 */
    BSP_LED_Toggle(LED1);
    /* This delay permit to user to see LED1 toggling*/
    HAL_Delay(100);
#else
    /* Synchronization between Master and Slave */
    Slave_Synchro();

    /* Receive command from Master */
    if(HAL_SPI_TransmitReceive(&SpiHandle, (uint8_t *)aDummyBuffer, paddrcmd, CMD_LENGTH, SPI_TIMEOUT_MAX) != HAL_OK)
    {
      Error_Handler();
    }

    /* 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_TransmitReceive(&SpiHandle, (uint8_t *)&ackbytes, (uint8_t *)aDummyBuffer, sizeof(ackbytes), SPI_TIMEOUT_MAX) != HAL_OK)
      {
        Error_Handler();
      }

      /* 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_TransmitReceive(&SpiHandle, aTxSlaveBuffer, (uint8_t *)aDummyBuffer, DATA_LENGTH, SPI_TIMEOUT_MAX) != HAL_OK)
        {
          Error_Handler();
        }

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

        /* Receive acknowledgement from Master */
        ackbytes = 0;
        if(HAL_SPI_TransmitReceive(&SpiHandle, (uint8_t *)aDummyBuffer, (uint8_t *)&ackbytes, sizeof(ackbytes), SPI_TIMEOUT_MAX) != HAL_OK)
        {
          Error_Handler();
        }

        /* 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_TransmitReceive(&SpiHandle, (uint8_t *)aDummyBuffer, aRxBuffer, DATA_LENGTH, SPI_TIMEOUT_MAX) != HAL_OK)
        {
          Error_Handler();
        }

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

        /* Send acknowledgement to Master */
        ackbytes = SPI_ACK_BYTES;
        if(HAL_SPI_TransmitReceive(&SpiHandle, (uint8_t *)&ackbytes, (uint8_t *)aDummyBuffer, sizeof(ackbytes), SPI_TIMEOUT_MAX) != HAL_OK)
        {
          Error_Handler();
        }

        /* 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_TransmitReceive(&SpiHandle, (uint8_t *)&ackbytes, (uint8_t *)aDummyBuffer, sizeof(ackbytes), SPI_TIMEOUT_MAX) != HAL_OK)
      {
        Error_Handler();
      }
      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
  {
    /* Call SPI write function to send command to slave */
    if(HAL_SPI_TransmitReceive(&SpiHandle, (uint8_t *)&txackbytes, (uint8_t *)&rxackbytes, 1, HAL_MAX_DELAY) != HAL_OK)
    {
      Error_Handler();
    }
  }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(&SpiHandle, (uint8_t *)&txackbyte, (uint8_t *)&rxackbyte, 1, HAL_MAX_DELAY) != HAL_OK)
    {
      Error_Handler();
    }
  }
  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
  *            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  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 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****/
