STM32CubeF4/Projects/STM32F412G-Discovery/Examples/I2C/I2C_TwoBoards_ComPolling/Src/main.c

/**
  ******************************************************************************
  * @file    I2C/I2C_TwoBoards_ComPolling/Src/main.c 
  * @author  MCD Application Team
  * @brief   This sample code shows how to use STM32F4xx 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
  *
  * Copyright (c) 2017 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */

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

/** @addtogroup STM32F4xx_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 SPEEDCLOCK define to max value: 400 KHz on STM32F4xx*/
#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 Polling****  ****I2C_TwoBoards communication based on Polling****  ****I2C_TwoBoards communication based on Polling**** ";

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

/* Private function prototypes -----------------------------------------------*/
static 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)
{

  /* STM32F4xx 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 100 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.ClockSpeed      = I2C_SPEEDCLOCK;
  I2cHandle.Init.DutyCycle       = I2C_DUTYCYCLE;
  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();
  }
  

#ifdef MASTER_BOARD
  
  /* Configure Joystick sel-button button */
  BSP_PB_Init(BUTTON_WAKEUP,BUTTON_MODE_GPIO);

  /* Wait for Joystick sel-button press before starting the Communication */
  while (BSP_PB_GetState(BUTTON_WAKEUP) != GPIO_PIN_RESET)
  {
  }

  /* Delay to avoid that possible signal rebound is taken as button release */
  HAL_Delay(50);
  
  /* Wait for Joystick sel-button release before starting the Communication */
  while (BSP_PB_GetState(BUTTON_WAKEUP) != 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 LED1 on: Transfer in Transmission process is correct */
  BSP_LED_On(LED1);

  /* Wait for Joystick sel-button press before starting the Communication */
  while (BSP_PB_GetState(BUTTON_WAKEUP) != GPIO_PIN_RESET)
  {
  }

  /* Delay to avoid that possible signal rebound is taken as button release */
  HAL_Delay(50);
  
  /* Wait for Joystick sel-button release before starting the Communication */
  while (BSP_PB_GetState(BUTTON_WAKEUP) != 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 LED1 off: Transfer in reception process is correct */
  BSP_LED_Off(LED1);
  
#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 LED1 on: Transfer in reception process is correct */
  BSP_LED_On(LED1);
  
  /*##-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 LED1 off: Transfer in transmission process is correct */
  BSP_LED_Off(LED1);
  
#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 (HSE)
  *            SYSCLK(Hz)                     = 100000000
  *            HCLK(Hz)                       = 100000000
  *            AHB Prescaler                  = 1
  *            APB1 Prescaler                 = 2
  *            APB2 Prescaler                 = 1
  *            HSE Frequency(Hz)              = 8000000
  *            PLL_M                          = 8
  *            PLL_N                          = 200
  *            PLL_P                          = 2
  *            PLL_Q                          = 7
  *            PLL_R                          = 2
  *            VDD(V)                         = 3.3
  *            Main regulator output voltage  = Scale1 mode
  *            Flash Latency(WS)              = 3
  * @param  None
  * @retval None
  */
static void SystemClock_Config(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  RCC_OscInitTypeDef RCC_OscInitStruct;
  HAL_StatusTypeDef ret = HAL_OK;

  /* Enable Power Control clock */
  __HAL_RCC_PWR_CLK_ENABLE();

  /* The voltage scaling allows optimizing the power consumption when the device is 
     clocked below the maximum system frequency, to update the voltage scaling value 
     regarding system frequency refer to product datasheet.  */
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  /* Enable HSE Oscillator and activate PLL with HSE as source */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = 8;
  RCC_OscInitStruct.PLL.PLLN = 200;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = 7;
  RCC_OscInitStruct.PLL.PLLR = 2;
  ret = HAL_RCC_OscConfig(&RCC_OscInitStruct);
  
  if(ret != HAL_OK)
  {
    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;  
  ret = HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_3);
  if(ret != HAL_OK)
  {
    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)
{
  /* Turn LED3 on: Transfer error in reception/transmission process */
  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;
}

#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


/**
  * @}
  */

/**
  * @}
  */