stm32f103c8t6用TIM3定时器控制输出四个PWM

好的，下面是使用TIM3定时器控制输出四个PWM的代码：

#include "stm32f10x.h"

#define PWM_PERIOD 1000 // PWM周期为1000

void TIM3_PWM_Init(void);

int main(void)
{
    TIM3_PWM_Init();

    while (1)
    {
        // 在这里可以改变PWM的占空比
        TIM_SetCompare1(TIM3, 500); // PB4
        TIM_SetCompare2(TIM3, 750); // PB5
        TIM_SetCompare3(TIM3, 250); // PB0
        TIM_SetCompare4(TIM3, 500); // PB1
    }
}

void TIM3_PWM_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStruct;
    TIM_TimeBaseInitTypeDef TIM_InitStruct;
    TIM_OCInitTypeDef TIM_OC_InitStruct;

    // 使能TIM3和GPIOB时钟
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

    // 配置GPIOB的PB4、PB5、PB0和PB1引脚为复用输出模式
    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_4 | GPIO_Pin_5 | GPIO_Pin_0 | GPIO_Pin_1;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOB, &GPIO_InitStruct);

    // TIM3基本配置
    TIM_InitStruct.TIM_Period = PWM_PERIOD - 1; // PWM周期
    TIM_InitStruct.TIM_Prescaler = 72 - 1; // 时钟预分频，72MHz/72=1MHz
    TIM_InitStruct.TIM_ClockDivision = TIM_CKD_DIV1; // 不分频
    TIM_InitStruct.TIM_CounterMode = TIM_CounterMode_Up; // 向上计数
    TIM_TimeBaseInit(TIM3, &TIM_InitStruct);

    // TIM3通道1 PWM配置
    TIM_OC_InitStruct.TIM_OCMode = TIM_OCMode_PWM1; // PWM模式1
    TIM_OC_InitStruct.TIM_OutputState = TIM_OutputState_Enable; // 输出使能
    TIM_OC_InitStruct.TIM_Pulse = 0; // 初始占空比为0
    TIM_OC_InitStruct.TIM_OCPolarity = TIM_OCPolarity_High; // 输出极性为高电平
    TIM_OC1Init(TIM3, &TIM_OC_InitStruct);

    // TIM3通道2 PWM配置
    TIM_OC_InitStruct.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OC_InitStruct.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OC_InitStruct.TIM_Pulse = 0;
    TIM_OC_InitStruct.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC2Init(TIM3, &TIM_OC_InitStruct);

    // TIM3通道3 PWM配置
    TIM_OC_InitStruct.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OC_InitStruct.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OC_InitStruct.TIM_Pulse = 0;
    TIM_OC_InitStruct.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC3Init(TIM3, &TIM_OC_InitStruct);

    // TIM3通道4 PWM配置
    TIM_OC_InitStruct.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OC_InitStruct.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OC_InitStruct.TIM_Pulse = 0;
    TIM_OC_InitStruct.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC4Init(TIM3, &TIM_OC_InitStruct);

    // 使能TIM3
    TIM_Cmd(TIM3, ENABLE);
}

上述代码中，使用了TIM3定时器来控制输出四个PWM信号，其中PWM周期为1000，时钟预分频为72，占空比可以通过`TIM_SetCompareX`函数来改变（X为1、2、3或4）。同时，需要注意在GPIO初始化中将PB4、PB5、PB0和PB1引脚配置为复用输出模式。