STM32F103C8T6单片机串口通信代码

以下是基于标准库的STM32F103C8T6单片机串口通信代码，可以参考：

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

#define USART1_DR_Base    0x40013804

void USART1_Init(void);
void USART1_SendChar(char ch);
void USART1_SendString(char* str);

int main(void)
{
    USART1_Init();
    
    while(1)
    {
        USART1_SendString("Hello World!\r\n");
        delay_ms(1000);
    }
}

void USART1_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    USART_InitTypeDef USART_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_USART1, ENABLE);

    //USART1_TX   PA.9
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    //USART1_RX   PA.10
    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_Rx | USART_Mode_Tx;
    USART_Init(USART1, &USART_InitStructure);

    USART_Cmd(USART1, ENABLE);
}

void USART1_SendChar(char ch)
{
    while (!(USART1->SR & USART_FLAG_TXE));
    USART1->DR = ch & 0xff;
}

void USART1_SendString(char* str)
{
    while (*str)
    {
        USART1_SendChar(*str++);
    }
}

void delay_ms(uint32_t ms)
{
    SysTick->LOAD = 72000 - 1;
    SysTick->VAL = 0;
    SysTick->CTRL = SysTick_CTRL_CLKSOURCE_Msk | SysTick_CTRL_ENABLE_Msk;

    while (ms--)
    {
        while (!(SysTick->CTRL & SysTick_CTRL_COUNTFLAG_Msk));
    }

    SysTick->CTRL &= ~SysTick_CTRL_ENABLE_Msk;
}

该代码初始化了USART1串口，波特率为9600，发送了“Hello World！”字符串，可以通过串口调试助手进行接收。注意此代码使用了SysTick进行延时。