编写一个stm32用tim定时器实现的跑马灯的代码

好的，这里是一个简单的跑马灯代码，使用TIM定时器实现：

#include "stm32f10x.h"

void TIM2_IRQHandler(void) {
    if (TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET) {
        // 翻转 PB0、PB1、PB2、PB3
        GPIO_WriteBit(GPIOB, GPIO_Pin_0, (BitAction)(1 - GPIO_ReadOutputDataBit(GPIOB, GPIO_Pin_0)));
        GPIO_WriteBit(GPIOB, GPIO_Pin_1, (BitAction)(1 - GPIO_ReadOutputDataBit(GPIOB, GPIO_Pin_1)));
        GPIO_WriteBit(GPIOB, GPIO_Pin_2, (BitAction)(1 - GPIO_ReadOutputDataBit(GPIOB, GPIO_Pin_2)));
        GPIO_WriteBit(GPIOB, GPIO_Pin_3, (BitAction)(1 - GPIO_ReadOutputDataBit(GPIOB, GPIO_Pin_3)));

        TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
    }
}

int main(void) {
    // 使能GPIOB和TIM2时钟
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

    // 配置GPIOB的PB0、PB1、PB2、PB3为推挽输出
    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOB, &GPIO_InitStructure);

    // 配置TIM2为每500ms触发一次中断
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_TimeBaseStructure.TIM_Period = 4999; // 500ms
    TIM_TimeBaseStructure.TIM_Prescaler = 7199; // 72MHz / 7200 = 10kHz
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

    // 使能TIM2溢出中断
    TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);

    // 启动TIM2
    TIM_Cmd(TIM2, ENABLE);

    // 启用全局中断
    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);

    while (1) {
        // 主循环不需要做什么
    }
}

这个代码使用TIM2定时器每500ms触发一次中断，然后在中断处理函数中翻转GPIOB的PB0、PB1、PB2、PB3引脚，实现跑马灯效果。