text: /**
    ******************************************************************************
    * @file    TIM/TIM_OCToggle/Src/main.c
    * @author  MCD Application Team
    * @version V1.0.2
    * @date    06-May-2016
    * @brief   This example shows how to configure the Timer to generate four different 
    *          signals with four different frequencies.
    ******************************************************************************
    * @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 STM32F4xx_HAL_Examples
    * @{
    */
  
  /** @addtogroup TIM_OCToggle
    * @{
    */
  
  /* Private typedef -----------------------------------------------------------*/
  /* Private define ------------------------------------------------------------*/
  /* Private macro -------------------------------------------------------------*/
  /* Private variables ---------------------------------------------------------*/
  __IO uint32_t uhCCR1_Val =  23076 ; 
  __IO uint32_t uhCCR2_Val = 11538 ;  
  __IO uint32_t uhCCR3_Val = 5769 ;  
  __IO uint32_t uhCCR4_Val = 2884 ; 
  
  uint32_t uhCapture = 0;
  
  /* Timer handler declaration */
  TIM_HandleTypeDef    TimHandle;
  
  /* Timer Output Compare Configuration Structure declaration */
  TIM_OC_InitTypeDef sConfig;
  
  /* Counter Prescaler value */
  uint32_t uwPrescalerValue = 0;
  
  /* Private function prototypes -----------------------------------------------*/
  static void SystemClock_Config(void);
  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 180 MHz */
    SystemClock_Config();
  
    /* Configure LED2 */
    BSP_LED_Init(LED2);
  
  
     /*##-1- Configure the TIM peripheral #######################################*/
    /* ---------------------------------------------------------------------------
    TIM3 Configuration: Output Compare Toggle Mode:
  
    To get TIM3 counter clock at 9 MHz, the prescaler is computed as follows:
    Prescaler = (TIM3CLK / TIM3 counter clock) - 1
    Prescaler = (SystemCoreClock/2 /9000000) - 1
  
    CC1 update rate = TIM3 counter clock / uhCCR1_Val
                    = 9 MHz/23076 = 390 Hz
    ==> So the TIM3 Channel 1 generates a periodic signal with a frequency equal
        to 195 Hz.
  
    CC2 update rate = TIM3 counter clock / uhCCR2_Val
                    = 9 MHz/11538 = 780 Hz
    ==> So the TIM3 Channel 2 generates a periodic signal with a frequency equal
        to 390 Hz.
  
    CC3 update rate = TIM3 counter clock / uhCCR3_Val
                    = 9 MHz/5769 = 1560 Hz
    ==> So the TIM3 Channel 3 generates a periodic signal with a frequency equal
        to 780 Hz.
  
    CC4 update rate = TIM3 counter clock / uhCCR4_Val
                    = 9 MHz/2884 = 3120 Hz
    ==> So the TIM3 Channel 4 generates a periodic signal with a frequency equal
        to 1560 Hz.
  
  
    --------------------------------------------------------------------------- */
  
  
  
    /* Compute the prescaler value to have TIM3 counter clock equal to 12.5 MHz */
     uwPrescalerValue = (uint32_t)(((SystemCoreClock/2) / 9000000) - 1); 
    
    TimHandle.Instance = TIM3;
    
    TimHandle.Init.Period        = 65535; 
    TimHandle.Init.Prescaler     = uwPrescalerValue;
    TimHandle.Init.ClockDivision = 0;
    TimHandle.Init.CounterMode   = TIM_COUNTERMODE_UP;
    if(HAL_TIM_OC_Init(&TimHandle) != HAL_OK)
    {
      /* Initialization Error */
      Error_Handler();
    }
    
    /*##-2- Configure the Output Compare channels ##############################*/ 
    /* Common configuration for all channels */
    sConfig.OCMode     = TIM_OCMODE_TOGGLE;
    sConfig.OCPolarity = TIM_OCPOLARITY_LOW;
  
    /* Output Compare Toggle Mode configuration: Channel1 */
    sConfig.Pulse = uhCCR1_Val;  
    if(HAL_TIM_OC_ConfigChannel(&TimHandle, &sConfig, TIM_CHANNEL_1) != HAL_OK)
    {
      /* Configuration Error */
      Error_Handler();
    }
    
    /* Output Compare Toggle Mode configuration: Channel2 */
    sConfig.Pulse = uhCCR2_Val;
    if(HAL_TIM_OC_ConfigChannel(&TimHandle, &sConfig, TIM_CHANNEL_2) != HAL_OK)
    {
      /* Configuration Error */
      Error_Handler();
    }
    
    /* Output Compare Toggle Mode configuration: Channel3 */
    sConfig.Pulse = uhCCR3_Val;
    if(HAL_TIM_OC_ConfigChannel(&TimHandle, &sConfig, TIM_CHANNEL_3) != HAL_OK)
    {
      /* Configuration Error */
      Error_Handler();
    }
    
    /* Output Compare Toggle Mode configuration: Channel4 */
    sConfig.Pulse = uhCCR4_Val;
    if(HAL_TIM_OC_ConfigChannel(&TimHandle, &sConfig, TIM_CHANNEL_4) != HAL_OK)
    {
      /* Configuration Error */
      Error_Handler();
    }
  
    /*##-3- Start signals generation #######################################*/ 
    /* Start channel 1 in Output compare mode */
    if(HAL_TIM_OC_Start_IT(&TimHandle, TIM_CHANNEL_1) != HAL_OK)
    {
      /* Starting Error */
      Error_Handler();
    }
    /* Start channel 2 in Output compare mode */
    if(HAL_TIM_OC_Start_IT(&TimHandle, TIM_CHANNEL_2) != HAL_OK)
    {
      /* Starting Error */
      Error_Handler();
    }
    /* Start channel 3 in Output compare mode */
    if(HAL_TIM_OC_Start_IT(&TimHandle, TIM_CHANNEL_3) != HAL_OK)
    {
      /* Starting Error */
      Error_Handler();
    }
    /* Start channel 4 in Output compare mode */
    if(HAL_TIM_OC_Start_IT(&TimHandle, TIM_CHANNEL_4) != HAL_OK)
    {
      /* Starting Error */
      Error_Handler();
    }
  
    while (1)
    {}
  }
  
  /**
    * @brief  Output Compare callback in non blocking mode 
    * @param  htim : TIM OC handle
    * @retval None
    */
  void HAL_TIM_OC_DelayElapsedCallback(TIM_HandleTypeDef *htim)
  {
    /* TIM3_CH1 toggling with frequency = 195 Hz */
    if(htim->Channel == HAL_TIM_ACTIVE_CHANNEL_1)
    {
      uhCapture = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_1);
      /* Set the Capture Compare Register value */
      __HAL_TIM_SET_COMPARE(&TimHandle, TIM_CHANNEL_1, (uhCapture + uhCCR1_Val));
    }
    
    /* TIM3_CH2 toggling with frequency = 390 Hz */
    if(htim->Channel == HAL_TIM_ACTIVE_CHANNEL_2)
    {
      uhCapture = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_2);
      /* Set the Capture Compare Register value */
      __HAL_TIM_SET_COMPARE(&TimHandle, TIM_CHANNEL_2, (uhCapture + uhCCR2_Val));   
    }
    
    /* TIM3_CH3 toggling with frequency = 780 Hz */
    if(htim->Channel == HAL_TIM_ACTIVE_CHANNEL_3)
    {
      uhCapture = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_3);
      /* Set the Capture Compare Register value */
      __HAL_TIM_SET_COMPARE(&TimHandle, TIM_CHANNEL_3, (uhCapture + uhCCR3_Val));
    }
    
    /* TIM3_CH4 toggling with frequency = 1560 Hz */
    if(htim->Channel == HAL_TIM_ACTIVE_CHANNEL_4)
    {
      uhCapture = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_4);
      /* Set the Capture Compare Register value */
      __HAL_TIM_SET_COMPARE(&TimHandle, TIM_CHANNEL_4, (uhCapture + uhCCR4_Val));
    }
  }
  
  /**
    * @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  System Clock Configuration
    *         The system Clock is configured as follow : 
    *            System Clock source            = PLL (HSE)
    *            SYSCLK(Hz)                     = 180000000
    *            HCLK(Hz)                       = 180000000
    *            AHB Prescaler                  = 1
    *            APB1 Prescaler                 = 4
    *            APB2 Prescaler                 = 2
    *            HSE Frequency(Hz)              = 8000000
    *            PLL_M                          = 8
    *            PLL_N                          = 360
    *            PLL_P                          = 2
    *            PLL_Q                          = 7
    *            VDD(V)                         = 3.3
    *            Main regulator output voltage  = Scale1 mode
    *            Flash Latency(WS)              = 5
    * @param  None
    * @retval None
    */
  static void SystemClock_Config(void)
  {
    RCC_ClkInitTypeDef RCC_ClkInitStruct;
    RCC_OscInitTypeDef RCC_OscInitStruct;
  
    /* 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_BYPASS;
    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
    RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
    RCC_OscInitStruct.PLL.PLLM = 8;
    RCC_OscInitStruct.PLL.PLLN = 360;
    RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
    RCC_OscInitStruct.PLL.PLLQ = 7;
    HAL_RCC_OscConfig(&RCC_OscInitStruct);
    
    /* Activate the Over-Drive mode */
    HAL_PWREx_EnableOverDrive();
    
    /* 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_DIV4;  
    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;  
    HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5);
  }
  
  #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****/
  