/**
  ******************************************************************************
  * @file    TIM_PWMOutput/main.c
  * @Author  MCD Application Team
  * @version V1.0.1
  * @date    11-November-2013
  * @brief   This example shows how to configure the TIM peripheral in PWM
  *         (Pulse Width Modulation) mode.
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; COPYRIGHT 2013 STMicroelectronics</center></h2>
  *
  * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
  * You may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *        http://www.st.com/software_license_agreement_liberty_v2
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
  ******************************************************************************
  */

/* Includes ------------------------------------------------------------------*/
#include "stm32f4xx.h"

/** @addtogroup STM32F4xx_StdPeriph_Examples
  * @{
  */

/** @addtogroup TIM_PWMOutput
  * @{
  */

/* Private typedef -----------------------------------------------------------*/
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
TIM_OCInitTypeDef  TIM_OCInitStructure;

/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
uint16_t CCR1_Val = 350;
uint16_t CCR2_Val = 262;
uint16_t CCR3_Val = 175;
uint16_t CCR4_Val = 87;
uint16_t PrescalerValue = 0;

/* Private function prototypes -----------------------------------------------*/
void TIM_Config(void);

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

/**
  * @brief  Main program
  * @param  None
  * @retval None
  */
int main(void)
{
  /*!< At this stage the microcontroller clock setting is already configured,
       this is done through SystemInit() function which is called from startup
       file (startup_stm32f429_439xx.s) before to branch to application main.
       To reconfigure the default setting of SystemInit() function, refer to
       system_stm32f4xx.c file
     */

  /* TIM Configuration */
  TIM_Config();
  
  /* -----------------------------------------------------------------------
    TIM4 Configuration: generate 4 PWM signals with 4 different duty cycles.
   
    In this example TIM4 input clock (TIM4CLK) is set to 4 * APB1 clock (PCLK1),
    since TIMPRE bit from RCC_DCKCFGR register is set.   
      TIM4CLK = 4 * PCLK1
      PCLK1 = HCLK / 4
      => TIM4CLK = HCLK = SystemCoreClock
         
    To get TIM4 counter clock at 21 MHz, the prescaler is computed as follows:
       Prescaler = (TIM4CLK / TIM4 counter clock) - 1
       Prescaler = (SystemCoreClock /21 MHz) - 1
                                             
    To get TIM4 output clock at 30 KHz, the period (ARR)) is computed as follows:
       ARR = (TIM4 counter clock / TIM4 output clock) - 1
           = 699
                  
    TIM4 Channel1 duty cycle = (TIM4_CCR1/ TIM4_ARR)* 100 = 50%
    TIM4 Channel2 duty cycle = (TIM4_CCR2/ TIM4_ARR)* 100 = 37.5%
    TIM4 Channel3 duty cycle = (TIM4_CCR3/ TIM4_ARR)* 100 = 25%
    TIM4 Channel4 duty cycle = (TIM4_CCR4/ TIM4_ARR)* 100 = 12.5%

    Note:
     SystemCoreClock variable holds HCLK frequency and is defined in system_stm32f4xx.c file.
     Each time the core clock (HCLK) changes, user had to call SystemCoreClockUpdate()
     function to update SystemCoreClock variable value. Otherwise, any configuration
     based on this variable will be incorrect.   
  ----------------------------------------------------------------------- */   
  RCC_TIMCLKPresConfig(RCC_TIMPrescActivated);

  /* Compute the prescaler value */
  PrescalerValue = (uint16_t) (SystemCoreClock / 21000000) - 1;

  /* Time base configuration */
  TIM_TimeBaseStructure.TIM_Period = 699;
  TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue;
  TIM_TimeBaseStructure.TIM_ClockDivision = 0;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

  TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);

  /* PWM1 Mode configuration: Channel1 */
  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = CCR1_Val;
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;

  TIM_OC1Init(TIM4, &TIM_OCInitStructure);

  TIM_OC1PreloadConfig(TIM4, TIM_OCPreload_Enable);

  /* PWM1 Mode configuration: Channel2 */
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = CCR2_Val;

  TIM_OC2Init(TIM4, &TIM_OCInitStructure);

  TIM_OC2PreloadConfig(TIM4, TIM_OCPreload_Enable);

  /* PWM1 Mode configuration: Channel3 */
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = CCR3_Val;

  TIM_OC3Init(TIM4, &TIM_OCInitStructure);

  TIM_OC3PreloadConfig(TIM4, TIM_OCPreload_Enable);

  /* PWM1 Mode configuration: Channel4 */
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = CCR4_Val;

  TIM_OC4Init(TIM4, &TIM_OCInitStructure);

  TIM_OC4PreloadConfig(TIM4, TIM_OCPreload_Enable);

  TIM_ARRPreloadConfig(TIM4, ENABLE);

  /* TIM4 enable counter */
  TIM_Cmd(TIM4, ENABLE);

  while (1)
  {}
}

/**
  * @brief  Configure the TIM4 Ouput Channels.
  * @param  None
  * @retval None
  */
void TIM_Config(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;

  /* TIM4 clock enable */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);

  /* GPIOD clock enable */
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);
  
  /* GPIOD Configuration: TIM4 CH1 (PD12), TIM4 CH2 (PD13), TIM4 CH3 (PD14) and TIM4 CH4 (PD15) */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12 | GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ;
  GPIO_Init(GPIOD, &GPIO_InitStructure);

  /* Connect TIM4 pins to AF2 */  
  GPIO_PinAFConfig(GPIOD, GPIO_PinSource12, GPIO_AF_TIM4);
  GPIO_PinAFConfig(GPIOD, GPIO_PinSource13, GPIO_AF_TIM4);
  GPIO_PinAFConfig(GPIOD, GPIO_PinSource14, GPIO_AF_TIM4);
  GPIO_PinAFConfig(GPIOD, GPIO_PinSource15, GPIO_AF_TIM4);
}

#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 ", file, line) */

  while (1)
  {}
}
#endif

/**
  * @}
  */

/**
  * @}
  */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/



這是ST官方的程序example
怎麼接可以看GPIO_Configuration()一般都會寫在裡面
調值就控制CCRx_Register

正点原子 发表于 2017-11-14 01:33
你从头开始学我们教程吧

绝对正确答案！

正点原子 发表于 2017-11-14 01:33
你从头开始学我们教程吧

或者从模电学起

你用switch语句来进行多路控制LED，PWM提前初始化设置好，就可以了