/**
  ******************************************************************************
  * @file    I2C/I2C_TwoBoards_ComDMA/Src/main.c 
  * @author  MCD Application Team
  * @brief   This sample code shows how to use STM32F1xx I2C HAL API to transmit
  *          and receive a data buffer with a communication process based on
  *          DMA 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 STM32F1xx_HAL_Examples
  * @{
  */

/** @addtogroup I2C_TwoBoards_ComDMA
  * @{
  */

/* 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        0x30F

/* I2C SPEEDCLOCK define to max value: 400 KHz on STM32F1xx*/
#define I2C_SPEEDCLOCK   400000
#define I2C_DUTYCYCLE    I2C_DUTYCYCLE_2

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


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

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

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

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

/**
  * @brief  Main program
  * @param  None
  * @retval None
  */
int main(void)
{
  /* STM32F103xB 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 I2C peripheral ######################################*/
  I2cHandle.Instance              = I2Cx;
  I2cHandle.Init.ClockSpeed       = I2C_SPEEDCLOCK;
  I2cHandle.Init.DutyCycle        = I2C_DUTYCYCLE;
  I2cHandle.Init.AddressingMode   = I2C_ADDRESSINGMODE_10BIT;
  I2cHandle.Init.DualAddressMode  = I2C_DUALADDRESS_DISABLE;
  I2cHandle.Init.GeneralCallMode  = I2C_GENERALCALL_DISABLE;
  I2cHandle.Init.NoStretchMode    = I2C_NOSTRETCH_DISABLE;  
  I2cHandle.Init.OwnAddress1      = I2C_ADDRESS;
  I2cHandle.Init.OwnAddress2      = 0xFF;
  
  if(HAL_I2C_Init(&I2cHandle) != HAL_OK)
  {
    /* Initialization Error */
    Error_Handler();
  }
  

#ifdef MASTER_BOARD
  
  /* Configure User push-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)
  {
  }
  
  /* Wait for User push-button release before starting the Communication */
  while (BSP_PB_GetState(BUTTON_USER) != GPIO_PIN_SET)
  {
  }
  
  /* The board sends the message and expects to receive it back */
  
  /*##-2- Start the transmission process #####################################*/  
  /* While the I2C in reception process, user can transmit data through 
     "aTxBuffer" buffer */
  while(HAL_I2C_Master_Transmit_DMA(&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();
    }
  }
  
  /*##-3- Wait for the end of the transfer ###################################*/  
  /*  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)
  {
  } 
  
  /* Wait for User push-button press before starting the Communication */
  while (BSP_PB_GetState(BUTTON_USER) != GPIO_PIN_RESET)
  {
  }
  
  /* Wait for User push-button release before starting the Communication */
  while (BSP_PB_GetState(BUTTON_USER) != GPIO_PIN_SET)
  {
  }

  /*##-4- Put I2C peripheral in reception process ###########################*/  
  while(HAL_I2C_Master_Receive_DMA(&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();
    }
  }

#else
  
  /* The board receives the message and sends it back */

  /*##-2- Put I2C peripheral in reception process ###########################*/  
  if(HAL_I2C_Slave_Receive_DMA(&I2cHandle, (uint8_t *)aRxBuffer, RXBUFFERSIZE) != HAL_OK)
  {
    /* Transfer error in reception process */
    Error_Handler();
  }
  
  /*##-3- Wait for the end of the transfer ###################################*/  
  /*  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- Start the transmission process #####################################*/  
  /* While the I2C in reception process, user can transmit data through 
     "aTxBuffer" buffer */
  if(HAL_I2C_Slave_Transmit_DMA(&I2cHandle, (uint8_t*)aTxBuffer, TXBUFFERSIZE)!= HAL_OK)
  {
    /* Transfer error in transmission process */
    Error_Handler();    
  }
  
#endif /* MASTER_BOARD */

  /*##-5- Wait for the end of the transfer ###################################*/  
  /*  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- Compare the sent and received buffers ##############################*/
  if(Buffercmp((uint8_t*)aTxBuffer,(uint8_t*)aRxBuffer,RXBUFFERSIZE))
  {
    /* Processing Error */
    Error_Handler();      
  }
 
  /* Infinite loop */  
  while (1)
  {
  }
}

/**
  * @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                         = 16
  *            Flash Latency(WS)              = 2
  * @param  None
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_ClkInitTypeDef clkinitstruct = {0};
  RCC_OscInitTypeDef oscinitstruct = {0};
  
  /* Configure PLL ------------------------------------------------------*/
  /* PLL configuration: PLLCLK = (HSI / 2) * PLLMUL = (8 / 2) * 16 = 64 MHz */
  /* PREDIV1 configuration: PREDIV1CLK = PLLCLK / HSEPredivValue = 64 / 1 = 64 MHz */
  /* Enable HSI and activate PLL with HSi_DIV2 as source */
  oscinitstruct.OscillatorType  = RCC_OSCILLATORTYPE_HSI;
  oscinitstruct.HSEState        = RCC_HSE_OFF;
  oscinitstruct.LSEState        = RCC_LSE_OFF;
  oscinitstruct.HSIState        = RCC_HSI_ON;
  oscinitstruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  oscinitstruct.HSEPredivValue    = RCC_HSE_PREDIV_DIV1;
  oscinitstruct.PLL.PLLState    = RCC_PLL_ON;
  oscinitstruct.PLL.PLLSource   = RCC_PLLSOURCE_HSI_DIV2;
  oscinitstruct.PLL.PLLMUL      = RCC_PLL_MUL16;
  if (HAL_RCC_OscConfig(&oscinitstruct)!= HAL_OK)
  {
    /* Initialization Error */
    while(1); 
  }

  /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 
     clocks dividers */
  clkinitstruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
  clkinitstruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  clkinitstruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  clkinitstruct.APB2CLKDivider = RCC_HCLK_DIV1;
  clkinitstruct.APB1CLKDivider = RCC_HCLK_DIV2;  
  if (HAL_RCC_ClockConfig(&clkinitstruct, FLASH_LATENCY_2)!= HAL_OK)
  {
    /* Initialization Error */
    while(1); 
  }
}

/**
  * @brief  Tx Transfer completed callback.
  * @param  I2cHandle: I2C handle. 
  * @note   This example shows a simple way to report end of DMA Tx transfer, and 
  *         you can add your own implementation. 
  * @retval None
  */
#ifdef MASTER_BOARD
void HAL_I2C_MasterTxCpltCallback(I2C_HandleTypeDef *I2cHandle)
{
  /* Toggle LED2: Transfer in transmission process is correct */
  BSP_LED_Toggle(LED2);
}
#else
void HAL_I2C_SlaveTxCpltCallback(I2C_HandleTypeDef *I2cHandle)
{
  /* Toggle LED2: Transfer in transmission process is correct */
  BSP_LED_Toggle(LED2);
}
#endif /* MASTER_BOARD */

/**
  * @brief  Rx Transfer completed callback.
  * @param  I2cHandle: I2C handle
  * @note   This example shows a simple way to report end of DMA Rx transfer, and 
  *         you can add your own implementation.
  * @retval None
  */
#ifdef MASTER_BOARD
void HAL_I2C_MasterRxCpltCallback(I2C_HandleTypeDef *I2cHandle)
{
  /* Toggle LED2: Transfer in reception process is correct */
  BSP_LED_Toggle(LED2);
}
#else
void HAL_I2C_SlaveRxCpltCallback(I2C_HandleTypeDef *I2cHandle)
{
  /* Toggle LED2: Transfer in reception process is correct */
  BSP_LED_Toggle(LED2);
}
#endif /* MASTER_BOARD */

/**
  * @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)
{
  Error_Handler();
}

/**
  * @brief  This function is executed in case of error occurrence.
  * @param  None
  * @retval None
  */
static void Error_Handler(void)
{
  /* Error if LED2 is slowly blinking (1 sec. period) */
  while(1)
  {    
    BSP_LED_Toggle(LED2); 
    HAL_Delay(1000);
  } 
}

/**
  * @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;
}

#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****/