/**
  ******************************************************************************
  * @file    I2C/I2C_TwoBoards_ComPolling/Src/main.c
  * @author  MCD Application Team
  * @brief   This sample code shows how to use STM32F0xx I2C 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</center></h2>
  *
  * Redistribution and use in source and binary forms, with or without modification,
  * are permitted provided that the following conditions are met:
  *   1. Redistributions of source code must retain the above copyright notice,
  *      this list of conditions and the following disclaimer.
  *   2. Redistributions in binary form must reproduce the above copyright notice,
  *      this list of conditions and the following disclaimer in the documentation
  *      and/or other materials provided with the distribution.
  *   3. Neither the name of STMicroelectronics nor the names of its contributors
  *      may be used to endorse or promote products derived from this software
  *      without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  ******************************************************************************
  */

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

/** @addtogroup STM32F0xx_HAL_Examples
  * @{
  */

/** @addtogroup I2C_TwoBoards_ComPolling
  * @{
  */

/* 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 TIMING Register define when I2C clock source is SYSCLK */
/* I2C TIMING is calculated in case of the I2C Clock source is the SYSCLK = 48 MHz */
/* This example use TIMING to 0x00A51314 to reach 1 MHz speed (Rise time = 100 ns, Fall time = 100 ns) */
#define I2C_TIMING      0x00A51314

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


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

/* 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)
{
  /* STM32F0xx 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.
       - Low Level Initialization
     */
  HAL_Init();

  /* Configure the system clock to 48 MHz */
  SystemClock_Config();

  /* Configure LED2 */
  BSP_LED_Init(LED2);


  /*##-1- Configure the I2C peripheral ######################################*/
  I2cHandle.Instance             = I2Cx;
  I2cHandle.Init.Timing          = I2C_TIMING;
  I2cHandle.Init.OwnAddress1     = I2C_ADDRESS;
  I2cHandle.Init.AddressingMode  = I2C_ADDRESSINGMODE_10BIT;
  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 */
  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)
  {
  }

  /* Delay to avoid that possible signal rebound is taken as button release */
  HAL_Delay(50);

  /* 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 */
  /* Timeout is set to 10S */
  while(HAL_I2C_Master_Transmit(&I2cHandle, (uint16_t)I2C_ADDRESS, (uint8_t*)aTxBuffer, TXBUFFERSIZE, 10000)!= 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();
    }
  }

  /* Turn LED2 on: Transfer in Transmission process is correct */
  BSP_LED_On(LED2);

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

  /* Delay to avoid that possible signal rebound is taken as button release */
  HAL_Delay(50);

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


  /*##-3- Put I2C peripheral in reception process ############################*/ 
  /* Timeout is set to 10S */ 
  while(HAL_I2C_Master_Receive(&I2cHandle, (uint16_t)I2C_ADDRESS, (uint8_t *)aRxBuffer, RXBUFFERSIZE, 10000) != HAL_OK)
  {
    /* Error_Handler() function is called when Timeout error occurs.
       When Acknowledge failure occurs (Slave don't acknowledge it's address)
       Master restarts communication */
    if (HAL_I2C_GetError(&I2cHandle) != HAL_I2C_ERROR_AF)
    {
      Error_Handler();
    }
  }

  /* Turn LED2 off: Transfer in reception process is correct */
  BSP_LED_Off(LED2);

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

  /*##-2- Put I2C peripheral in reception process ############################*/ 
  /* Timeout is set to 10S  */
  if(HAL_I2C_Slave_Receive(&I2cHandle, (uint8_t *)aRxBuffer, RXBUFFERSIZE, 10000) != HAL_OK)
  {
    /* Transfer error in reception process */
    Error_Handler();
  }

  /* Turn LED2 on: Transfer in reception process is correct */
  BSP_LED_On(LED2);

  /*##-3- Start the transmission process #####################################*/  
  /* While the I2C in reception process, user can transmit data through 
     "aTxBuffer" buffer */
  /* Timeout is set to 10S */
  if(HAL_I2C_Slave_Transmit(&I2cHandle, (uint8_t*)aTxBuffer, TXBUFFERSIZE, 10000)!= HAL_OK)
  {
    /* Transfer error in transmission process */
    Error_Handler();
  }

  /* Turn LED2 off: Transfer in transmission process is correct */
  BSP_LED_Off(LED2);
  
#endif /* MASTER_BOARD */

  /*##-4- 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)                     = 48000000
  *            HCLK(Hz)                       = 48000000
  *            AHB Prescaler                  = 1
  *            APB1 Prescaler                 = 1
  *            HSI Frequency(Hz)              = 8000000
  *            PREDIV                         = 2
  *            PLLMUL                         = 12
  *            Flash Latency(WS)              = 1
  * @param  None
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  RCC_OscInitTypeDef RCC_OscInitStruct;
  
  /* No HSE Oscillator on Nucleo, 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_MUL12;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct)!= HAL_OK)
  {
    /* Initialization Error */
    while(1); 
  }

  /* Select PLL as system clock source and configure the HCLK, PCLK1 clocks dividers */
  RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1);
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1)!= 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)
{
  /** Error_Handler() function is called when error occurs.
    * 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)
  {
    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(char* 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****/
