STM32F103C8T6定时器3输出4路PWM波标准库

以下是STM32F103C8T6定时器3输出4路PWM波标准库的代码：

#include "stm32f10x.h"

void TIM3_PWM_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_OCInitTypeDef TIM_OCInitStructure;
    
    //使能GPIOB和TIM3的时钟
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
    
    //将PB0、PB1、PB4、PB5配置为复用推挽输出模式
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_4 | GPIO_Pin_5;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOB, &GPIO_InitStructure);
    
    //定时器TIM3初始化
    TIM_TimeBaseStructure.TIM_Period = 1999;   //计数器自动重装值
    TIM_TimeBaseStructure.TIM_Prescaler = 71;  //定时器分频
    TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
    
    //PWM模式初始化
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;  //PWM模式1
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse = 0;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    
    //CH1 PWM输出初始化
    TIM_OC1Init(TIM3, &TIM_OCInitStructure);
    TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);
    
    //CH2 PWM输出初始化
    TIM_OC2Init(TIM3, &TIM_OCInitStructure);
    TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);
    
    //CH3 PWM输出初始化
    TIM_OC3Init(TIM3, &TIM_OCInitStructure);
    TIM_OC3PreloadConfig(TIM3, TIM_OCPreload_Enable);
    
    //CH4 PWM输出初始化
    TIM_OC4Init(TIM3, &TIM_OCInitStructure);
    TIM_OC4PreloadConfig(TIM3, TIM_OCPreload_Enable);
    
    //启动TIM3
    TIM_Cmd(TIM3, ENABLE);
}

注：以上代码中，定时器TIM3的频率为84MHz/72=1.1667MHz，PWM波的频率为1.1667MHz/2000=583.3Hz。对于每个PWM通道，占空比范围为0-1999，对应的占空比范围为0%-100%。在使用时，可以通过修改TIM_OCInitStructure.TIM_Pulse的值来改变占空比。