STM32标准库串口通信程序

以下是一个基于STM32标准库实现串口通信的程序示例，假设使用的是STM32F4系列芯片和Keil C编译器。程序中使用的是USART库函数进行串口的配置和通信，具体的串口口和引脚需要根据实际硬件接线情况进行修改。

#include "stm32f4xx.h"
#include <stdio.h>

USART_InitTypeDef USART_InitStructure;

void USART_Configuration(void) {
  GPIO_InitTypeDef GPIO_InitStructure;

  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);

  GPIO_PinAFConfig(GPIOA, GPIO_PinSource2, GPIO_AF_USART2);
  GPIO_PinAFConfig(GPIOA, GPIO_PinSource3, GPIO_AF_USART2);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2 | GPIO_Pin_3;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
  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(USART2, &USART_InitStructure);

  USART_Cmd(USART2, ENABLE);
}

int main(void) {
  char ch;

  USART_Configuration();

  while(1) {
    if(USART_GetFlagStatus(USART2, USART_FLAG_RXNE) == SET) {
      ch = USART_ReceiveData(USART2);
      USART_SendData(USART2, ch);
      while(USART_GetFlagStatus(USART2, USART_FLAG_TXE) == RESET);
    }
  }
}

该程序实现了通过USART2串口接收并回传数据，USART_GetFlagStatus函数用于检测接收到数据，USART_ReceiveData函数用于接收数据，USART_SendData函数用于回传数据。USART_InitStructure结构体用于配置串口的波特率、数据位、停止位、校验位等参数，可以根据实际需要进行修改。