stm32f103 pa15输出pwm波形的代码

以下是使用STM32F103的PA15输出PWM波形的示例代码：

#include "stm32f10x.h"

void GPIO_Configuration(void);
void TIM_Configuration(void);

int main(void)
{
    GPIO_Configuration();
    TIM_Configuration();

    while(1);
}

void GPIO_Configuration(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
}

void TIM_Configuration(void)
{
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_OCInitTypeDef TIM_OCInitStructure;

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

    TIM_TimeBaseStructure.TIM_Period = 999; // PWM周期为1000个计数器时钟周期
    TIM_TimeBaseStructure.TIM_Prescaler = 71; // 时钟预分频为72，计数器时钟频率为1MHz
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse = 500; // 占空比为50%
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC1Init(TIM2, &TIM_OCInitStructure);

    TIM_Cmd(TIM2, ENABLE);
}

在此代码中，我们使用PA15作为TIM2的通道1输出PWM波形。TIM2的计数器时钟频率为1MHz，PWM周期为1000个计数器时钟周期，并且占空比为50%。