stm32f103 串口发送 代码

下面是一个基本的 STM32F103 串口发送代码：

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

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

int main(void) {
    USART1_Init();
    USART1_SendString("Hello World!\r\n");

    while(1) {}
}

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

    // Enable clock for GPIOA and USART1
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_USART1, ENABLE);

    // Configure USART1 Tx (PA9) as alternate function push-pull
    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);

    // Configure USART1 Rx (PA10) as input floating
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    // Configure USART1
    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);

    // Enable USART1
    USART_Cmd(USART1, ENABLE);
}

void USART1_SendChar(char ch) {
    // Wait until transmit data register is empty
    while(!(USART1->SR & USART_SR_TXE));
    // Send character
    USART1->DR = (ch & 0xFF);
}

void USART1_SendString(char* str) {
    // Send characters until null terminator is reached
    while(*str) {
        USART1_SendChar(*str++);
    }
}

这个代码初始化了 USART1 串口，并发送了 "Hello World!" 到电脑。串口的波特率是 9600，8 位数据位，1 个停止位，无校验。在 `main` 函数中调用 `USART1_Init` 函数初始化串口，调用 `USART1_SendString` 函数发送字符串。 `USART1_SendChar` 函数用于发送单个字符。