stm32f103c8t6通过串口实现计时

要通过串口实现计时，你需要在代码中使用定时器和串口相关的库函数。下面是一个基本的代码框架：

1. 初始化定时器和串口

#include <stdio.h>
#include "stm32f10x.h"

void TIM2_Configuration(void);
void USART1_Configuration(void);

int main(void)
{
    TIM2_Configuration();
    USART1_Configuration();

    while(1)
    {
        // TODO: 处理其他任务
    }
}

void TIM2_Configuration(void)
{
    TIM_TimeBaseInitTypeDef TIM_InitStructure;

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

    TIM_InitStructure.TIM_Period = 1000; // 定时器周期为 1 秒
    TIM_InitStructure.TIM_Prescaler = 7200 - 1; // 定时器时钟频率为 72 MHz / 7200 = 10 kHz
    TIM_InitStructure.TIM_ClockDivision = 0;
    TIM_InitStructure.TIM_CounterMode = TIM_CounterMode_Up;

    TIM_TimeBaseInit(TIM2, &TIM_InitStructure);

    TIM_Cmd(TIM2, ENABLE);
}

void USART1_Configuration(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    USART_InitTypeDef USART_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_USART1, ENABLE);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    USART_InitStructure.USART_BaudRate = 9600;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;
    USART_InitStructure.USART_StopBits = USART_StopBits_1;
    USART_InitStructure.USART_Parity = USART_Parity_No;
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStructure.USART_Mode = USART_Mode_Tx;

    USART_Init(USART1, &USART_InitStructure);

    USART_Cmd(USART1, ENABLE);
}

2. 在定时器中断处理函数中实现计时和发送串口数据

void TIM2_IRQHandler(void)
{
    static uint32_t count = 0;
    char buffer[32];

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

        count++;

        if (count >= 3600) // 1 小时
        {
            count = 0;

            sprintf(buffer, "Time: %d h\r\n", count);
            USART_SendString(USART1, buffer);
        }
    }
}

在该代码中，我们在每次定时器中断发生时，将计时器加 1，并在计时器达到 1 小时后，将时间通过串口发送出去。你可以根据需要修改计时器周期以及发送的数据格式。