pwm方波输出

文章目录

pwm方波输出

前言

pwm是什么

蓝桥桥杯是怎么考pwm输出的

具体步骤

  • 官方库中的标准例程
  • #修改代码
  • 时钟和GPIO
  • 输出频率的初始化
  • 不同占空比的pwm波输出
  • 验证程序是否工作
  • 总结（重要）
  • 调用（关键部分）
  • 修改后的完整代码如下
  • 调用举例

前言

近些年来，蓝桥杯嵌入式的考察越来越注重逻辑的设计，硬件部分代码量也逐渐增多，这就对如何快速地完成外设部分的程序提出了挑战。 下面，带大家利用官方的外设参考例程来快速完成自己的代码。这篇文章讲的是常用的外设，pwm。

pwm是什么

脉宽调制（PWM）基本原理：控制方式就是对逆变电路开关器件的通断进行控制，使输出端得到一系列幅值相等但宽度不一致的脉冲，用这些脉冲来代替正弦波或所需要的波形。也就是在输出波形的半个周期中产生多个脉冲，使各脉冲的等值电压为正弦波形，所获得的输出平滑且低次谐波少。按一定的规则对各脉冲的宽度进行调制，既可改变逆变电路输出电压的大小，也可改变输出频率。想必大家都有一定的程序设计基础，这里就不过多介绍了。 简而言之，我们的目的是要快速输出占空比和频率可调的方波。

蓝桥桥杯是怎么考pwm输出的

这里给出往年的考法

输出pesq的wb是什么 pqw是什么类型输出_输出pesq的wb是什么

输出pesq的wb是什么 pqw是什么类型输出_单片机_02

输出pesq的wb是什么 pqw是什么类型输出_输出pesq的wb是什么_03

具体步骤

为了快速的的完成代码，我们对官方的例程来进行修改。

官方库中的标准例程

意法半导体的标准外设库，在赛点资源包的位置

输出pesq的wb是什么 pqw是什么类型输出_输出pesq的wb是什么_04

官方给的例程在如下路径

6-STM32固件库代码V3.5版\stm32f10x_stdperiph_lib\STM32F10x_StdPeriph_Lib_V3.5.0\Project\STM32F10x_StdPeriph_Examples

输出pesq的wb是什么 pqw是什么类型输出_初始化_05

我们要使用的pwm输出在TIM文件夹中 如下路径 

STM32F10x_StdPeriph_Lib_V3.5.0\Project\STM32F10x_StdPeriph_Examples\TIM\PWM_Output

找到main.c修改车pwm.c，然后加入到工程之中。 完整源代码如下

#include "stm32f10x.h"

/** @addtogroup STM32F10x_StdPeriph_Examples
  * @{
  */

/** @addtogroup TIM_PWM_Output
  * @{
  */ 

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
TIM_OCInitTypeDef  TIM_OCInitStructure;
uint16_t CCR1_Val = 333;
uint16_t CCR2_Val = 249;
uint16_t CCR3_Val = 166;
uint16_t CCR4_Val = 83;
uint16_t PrescalerValue = 0;

/* Private function prototypes -----------------------------------------------*/
void RCC_Configuration(void);
void GPIO_Configuration(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_stm32f10x_xx.s) before to branch to application main.
       To reconfigure the default setting of SystemInit() function, refer to
       system_stm32f10x.c file
     */     
       
  /* System Clocks Configuration */
  RCC_Configuration();

  /* GPIO Configuration */
  GPIO_Configuration();

  /* -----------------------------------------------------------------------
    TIM3 Configuration: generate 4 PWM signals with 4 different duty cycles:
    The TIM3CLK frequency is set to SystemCoreClock (Hz), to get TIM3 counter
    clock at 24 MHz the Prescaler is computed as following:
     - Prescaler = (TIM3CLK / TIM3 counter clock) - 1
    SystemCoreClock is set to 72 MHz for Low-density, Medium-density, High-density
    and Connectivity line devices and to 24 MHz for Low-Density Value line and
    Medium-Density Value line devices

    The TIM3 is running at 36 KHz: TIM3 Frequency = TIM3 counter clock/(ARR + 1)
                                                  = 24 MHz / 666 = 36 KHz
    TIM3 Channel1 duty cycle = (TIM3_CCR1/ TIM3_ARR)* 100 = 50%
    TIM3 Channel2 duty cycle = (TIM3_CCR2/ TIM3_ARR)* 100 = 37.5%
    TIM3 Channel3 duty cycle = (TIM3_CCR3/ TIM3_ARR)* 100 = 25%
    TIM3 Channel4 duty cycle = (TIM3_CCR4/ TIM3_ARR)* 100 = 12.5%
  ----------------------------------------------------------------------- */
  /* Compute the prescaler value */
  PrescalerValue = (uint16_t) (SystemCoreClock / 24000000) - 1;
  /* Time base configuration */
  TIM_TimeBaseStructure.TIM_Period = 665;
  TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue;
  TIM_TimeBaseStructure.TIM_ClockDivision = 0;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

  TIM_TimeBaseInit(TIM3, &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(TIM3, &TIM_OCInitStructure);

  TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);

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

  TIM_OC2Init(TIM3, &TIM_OCInitStructure);

  TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);

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

  TIM_OC3Init(TIM3, &TIM_OCInitStructure);

  TIM_OC3PreloadConfig(TIM3, TIM_OCPreload_Enable);

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

  TIM_OC4Init(TIM3, &TIM_OCInitStructure);

  TIM_OC4PreloadConfig(TIM3, TIM_OCPreload_Enable);

  TIM_ARRPreloadConfig(TIM3, ENABLE);

  /* TIM3 enable counter */
  TIM_Cmd(TIM3, ENABLE);

  while (1)
  {}
}

/**
  * @brief  Configures the different system clocks.
  * @param  None
  * @retval None
  */
void RCC_Configuration(void)
{
  /* TIM3 clock enable */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);

  /* GPIOA and GPIOB clock enable */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB |
                         RCC_APB2Periph_GPIOC | RCC_APB2Periph_AFIO, ENABLE);
}

/**
  * @brief  Configure the TIM3 Ouput Channels.
  * @param  None
  * @retval None
  */
void GPIO_Configuration(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;

#ifdef STM32F10X_CL
  /*GPIOB Configuration: TIM3 channel1, 2, 3 and 4 */
  GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_6 | GPIO_Pin_7 | GPIO_Pin_8 | GPIO_Pin_9;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

  GPIO_Init(GPIOC, &GPIO_InitStructure);

  GPIO_PinRemapConfig(GPIO_FullRemap_TIM3, ENABLE);	

#else
  /* GPIOA Configuration:TIM3 Channel1, 2, 3 and 4 as alternate function push-pull */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

  GPIO_Init(GPIOA, &GPIO_InitStructure);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1;
  GPIO_Init(GPIOB, &GPIO_InitStructure);
#endif
}

#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) */

  while (1)
  {}
}

#endif

/**
  * @}
  */ 

/**
  * @}
  */ 

/******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE****/

代码主体由三个函数够成

RCC_Configuration(); 负责初始化使用到的时钟3 GPIO_Configuration(); 负责负责GPIO的初始化 int main() 负责总的pwm初始化，调用前两个函数

还有部分代码是

#ifdef  USE_FULL_ASSERT

包含起来的部分，删不删都没有影响。

#修改代码

时钟和GPIO

在官方开发板，ct117e这块板子上会用到的GPIO口有PA6PA7 分别对应TIM3的通道1和通道2 在上面代码里面，刚好会初始化到这两个口和对应的时钟，所以这一部分我们不需要改动都行。

输出频率的初始化

pwm输出频率的计算公式

freq= SystemCoreClock / (（TIM_Period+1）*（TIM_Prescaler +1））-1 eg: 假设我要PWM波的TIM3以2KHZ的频率运行（系统时钟 = 72MHZ） 且此时我们把arr = 99（即百分制），要输出频率，可以用频率做参数，代入上公式可计算出预分频的值 PrescalerValue = (uint16_t) (SystemCoreClock / 100/freq) - 1;

TIM_TimeBaseStructure.TIM_Period = 665;
 TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue;

为了能方便修改频率，我们将需要的频率作为参数输入函数中即可 将函数修改成如下代码

void pwm_init(u16 freq)
{

  /* System Clocks Configuration */
  RCC_Configuration();

  /* GPIO Configuration */
  GPIO_Configuration();


  /* Compute the prescaler value */
  PrescalerValue = (uint16_t) (SystemCoreClock / 100/freq) - 1;
  /* Time base configuration */
  TIM_TimeBaseStructure.TIM_Period =99;//此处周期和上面的100对应，100-1，
  TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue;
  TIM_TimeBaseStructure.TIM_ClockDivision = 0;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

  TIM_TimeBaseInit(TIM3, &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(TIM3, &TIM_OCInitStructure);

  TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);

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

  TIM_OC2Init(TIM3, &TIM_OCInitStructure);

  TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);

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

  TIM_OC3Init(TIM3, &TIM_OCInitStructure);

  TIM_OC3PreloadConfig(TIM3, TIM_OCPreload_Enable);

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

  TIM_OC4Init(TIM3, &TIM_OCInitStructure);

  TIM_OC4PreloadConfig(TIM3, TIM_OCPreload_Enable);

  TIM_ARRPreloadConfig(TIM3, ENABLE);

  /* TIM3 enable counter */
  TIM_Cmd(TIM3, ENABLE);
}

有两处值得注意

将频率作为参数传人函数

删除函数底部的while（1）空循环，避免程序卡在此处

不同占空比的pwm波输出

使用函数 void TIM_SetCompare1(TIM_TypeDef* TIMx, uint16_t Compare1); 这里setCompare1里的1是指通道，1就是通道1，同样的TIM_SetCompare2就是设置通道2的占空比。

在初始化程序完成后使用TIM_SetCompare1可以设置PA6的占空比，TIM_SetCompare2可以设置PA7的占空比 eg:设置PA6的占空比为60 % ：TIM_SetCompare1(TIM3,60); //前提的配置是TIM_TimeBaseStructure.TIM_Period=99；这样比较好计算占空比，即输入的参数就是占空比，输入参数为0可以视为不输出。初始化函数末尾，可使用TIM_SetCompare1(TIM3,0)使板子先不输出方波；

进一步了解周期和频率的改变方法，可以参考下这篇文章练习STM32动态更改PWM波频率和占空比

验证程序是否工作

在考场上可以要示波器，其实也可以自己用keil的仿真来看是否输出了pwm波，仿真方法如下，同时也适用于GPIO口状态的仿真。

  1. 进入仿真，魔术棒点开，找到Debug项，勾选 Use simulator 使用仿真 然后退出来，工具栏中点开仿真
  2. 打开这个，逻辑分析

输出pesq的wb是什么 pqw是什么类型输出_蓝桥杯_06

如图：

输出pesq的wb是什么 pqw是什么类型输出_单片机_07

  1. 点击setup，设置要监测的GPIO口，eg:输入PORTA.6 监测PA6 输入后是这个样子
  2. 右键，将模式换为bit 即可观测输出方波

总结（重要）

调用（关键部分）

将PWM_Output文件夹中的mian.c文件复制到工程中，改名成pwm.c。

将函数头 int mian()改为void pwm_init((u16 freq),同时将函数中的while（1）空循环删去。

在自己的主函数中调用pwm_init(freq)，初始化频率，使用TIM_SetComparex来改变占空比。

修改后的完整代码如下

pwm.c

/**
  ******************************************************************************
  * @file    TIM/PWM_Output/main.c 
  * @author  MCD Application Team
  * @version V3.5.0
  * @date    08-April-2011
  * @brief   Main program body
  ******************************************************************************
  * @attention
  *
  * THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
  * WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE
  * TIME. AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY
  * DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING
  * FROM THE CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE
  * CODING INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
  *
  * <h2><center>© COPYRIGHT 2011 STMicroelectronics</center></h2>
  ******************************************************************************
  */ 

/* Includes ------------------------------------------------------------------*/
#include "stm32f10x.h"

/** @addtogroup STM32F10x_StdPeriph_Examples
  * @{
  */

/** @addtogroup TIM_PWM_Output
  * @{
  */ 

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
TIM_OCInitTypeDef  TIM_OCInitStructure;
uint16_t CCR1_Val = 333;
uint16_t CCR2_Val = 249;
uint16_t CCR3_Val = 166;
uint16_t CCR4_Val = 83;
uint16_t PrescalerValue = 0;

/* Private function prototypes -----------------------------------------------*/
void RCC_Configuration(void);
void GPIO_Configuration(void);

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

/**
  * @brief  Main program
  * @param  None
  * @retval None
  */
void pwm_init(u16 freq)
{
  /*!< At this stage the microcontroller clock setting is already configured, 
       this is done through SystemInit() function which is called from startup
       file (startup_stm32f10x_xx.s) before to branch to application main.
       To reconfigure the default setting of SystemInit() function, refer to
       system_stm32f10x.c file
     */     
       
  /* System Clocks Configuration */
  RCC_Configuration();

  /* GPIO Configuration */
  GPIO_Configuration();

  /* -----------------------------------------------------------------------
    TIM3 Configuration: generate 4 PWM signals with 4 different duty cycles:
    The TIM3CLK frequency is set to SystemCoreClock (Hz), to get TIM3 counter
    clock at 24 MHz the Prescaler is computed as following:
     - Prescaler = (TIM3CLK / TIM3 counter clock) - 1
    SystemCoreClock is set to 72 MHz for Low-density, Medium-density, High-density
    and Connectivity line devices and to 24 MHz for Low-Density Value line and
    Medium-Density Value line devices

    The TIM3 is running at 36 KHz: TIM3 Frequency = TIM3 counter clock/(ARR + 1)
                                                  = 24 MHz / 666 = 36 KHz
    TIM3 Channel1 duty cycle = (TIM3_CCR1/ TIM3_ARR)* 100 = 50%
    TIM3 Channel2 duty cycle = (TIM3_CCR2/ TIM3_ARR)* 100 = 37.5%
    TIM3 Channel3 duty cycle = (TIM3_CCR3/ TIM3_ARR)* 100 = 25%
    TIM3 Channel4 duty cycle = (TIM3_CCR4/ TIM3_ARR)* 100 = 12.5%
  ----------------------------------------------------------------------- */
  /* Compute the prescaler value */
  PrescalerValue = (uint16_t) (SystemCoreClock / 100/freq) - 1;
  /* Time base configuration */
  TIM_TimeBaseStructure.TIM_Period = 99;
  TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue;
  TIM_TimeBaseStructure.TIM_ClockDivision = 0;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

  TIM_TimeBaseInit(TIM3, &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(TIM3, &TIM_OCInitStructure);

  TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);

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

  TIM_OC2Init(TIM3, &TIM_OCInitStructure);

  TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);

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

  TIM_OC3Init(TIM3, &TIM_OCInitStructure);

  TIM_OC3PreloadConfig(TIM3, TIM_OCPreload_Enable);

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

  TIM_OC4Init(TIM3, &TIM_OCInitStructure);

  TIM_OC4PreloadConfig(TIM3, TIM_OCPreload_Enable);

  TIM_ARRPreloadConfig(TIM3, ENABLE);

  /* TIM3 enable counter */
  TIM_Cmd(TIM3, ENABLE);

}

/**
  * @brief  Configures the different system clocks.
  * @param  None
  * @retval None
  */
void RCC_Configuration(void)
{
  /* TIM3 clock enable */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);

  /* GPIOA and GPIOB clock enable */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB |
                         RCC_APB2Periph_GPIOC | RCC_APB2Periph_AFIO, ENABLE);
}

/**
  * @brief  Configure the TIM3 Ouput Channels.
  * @param  None
  * @retval None
  */
void GPIO_Configuration(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;

#ifdef STM32F10X_CL
  /*GPIOB Configuration: TIM3 channel1, 2, 3 and 4 */
  GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_6 | GPIO_Pin_7 | GPIO_Pin_8 | GPIO_Pin_9;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

  GPIO_Init(GPIOC, &GPIO_InitStructure);

  GPIO_PinRemapConfig(GPIO_FullRemap_TIM3, ENABLE);	

#else
  /* GPIOA Configuration:TIM3 Channel1, 2, 3 and 4 as alternate function push-pull */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

  GPIO_Init(GPIOA, &GPIO_InitStructure);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1;
  GPIO_Init(GPIOB, &GPIO_InitStructure);
#endif
}

#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) */

  while (1)
  {}
}

#endif

/**
  * @}
  */ 

/**
  * @}
  */ 

/******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE****/

函数额外初始化了别的GPIO口，要精简的可以注意下。

调用举例

main.c中初始化：

输出pesq的wb是什么 pqw是什么类型输出_蓝桥杯_08

然后使用：

输出pesq的wb是什么 pqw是什么类型输出_初始化_09

设置通道二的占空比。然后仿真就可以看到输出的方波了。