生成一个用stm32pwm控制机直流减速电机的代码，用到定时器中断控制PWm

以下是一个简单的使用定时器中断控制PWM的例子，用于控制机直流减速电机：

#include "stm32f10x.h"

#define PWM_PERIOD 1000 // PWM 的周期

void TIM2_IRQHandler(void) {
    static uint16_t duty_cycle = 0; // 占空比
    static uint8_t direction = 0; // 方向

    if (TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET) {
        TIM_ClearITPendingBit(TIM2, TIM_IT_Update);

        if (direction == 0) { // 正向
            duty_cycle += 10;
            if (duty_cycle >= PWM_PERIOD) {
                duty_cycle = PWM_PERIOD;
                direction = 1; // 反向
            }
        } else { // 反向
            duty_cycle -= 10;
            if (duty_cycle <= 0) {
                duty_cycle = 0;
                direction = 0; // 正向
            }
        }

        TIM_SetCompare1(TIM2, duty_cycle); // 设置占空比
    }
}

int main(void) {
    // 初始化 GPIO 和定时器
    GPIO_InitTypeDef GPIO_InitStructure;
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_OCInitTypeDef TIM_OCInitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
    TIM_TimeBaseStructure.TIM_Period = PWM_PERIOD - 1;
    TIM_TimeBaseStructure.TIM_Prescaler = SystemCoreClock / (2 * PWM_PERIOD) - 1;
    TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse = 0;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC1Init(TIM2, &TIM_OCInitStructure);
    TIM_OC1PreloadConfig(TIM2, TIM_OCPreload_Enable);

    TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);

    NVIC_InitTypeDef NVIC_InitStructure;
    NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    TIM_Cmd(TIM2, ENABLE);

    while (1) {
        // 占空比由定时器中断控制
    }
}

在此例子中，我们使用了定时器 TIM2 和 GPIOA 的第 0 个引脚来控制 PWM 信号。我们在定时器的中断处理函数中不断地改变占空比和方向，从而实现 PWM 信号的控制。在主循环中，我们什么也不干，因为占空比由定时器中断控制。