STM32F4_USART3 通信代码（仅供参考）

#include "USART3.h"


void USART3_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct;
NVIC_InitTypeDef NVIC_InitStruct;
USART_InitTypeDef USART_InitStruct;
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB,ENABLE);
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1,ENABLE);
  GPIO_PinAFConfig(GPIOB,GPIO_PinSource6,GPIO_AF_USART3);
  
  GPIO_PinAFConfig( GPIOB, GPIO_PinSource6,GPIO_AF_USART3);
  GPIO_PinAFConfig( GPIOB, GPIO_PinSource7,GPIO_AF_USART3);
  GPIO_InitStruct.GPIO_Mode=GPIO_Mode_AF;
  GPIO_InitStruct.GPIO_OType=GPIO_OType_PP;
  GPIO_InitStruct.GPIO_Pin=GPIO_Pin_6;
  GPIO_InitStruct.GPIO_PuPd=GPIO_PuPd_UP;
  GPIO_InitStruct.GPIO_Speed=GPIO_High_Speed;
  GPIO_Init(GPIOB,&GPIO_InitStruct);
GPIO_InitStruct.GPIO_Pin=GPIO_Pin_7;
GPIO_Init(GPIOB,&GPIO_InitStruct);
USART_InitStruct.USART_BaudRate=115200;
  USART_InitStruct.USART_HardwareFlowControl=USART_HardwareFlowControl_None;
USART_InitStruct.USART_Mode=USART_Mode_Rx|USART_Mode_Tx;
USART_InitStruct.USART_Parity=USART_Parity_No;
USART_InitStruct.USART_StopBits=USART_StopBits_1;
USART_InitStruct.USART_WordLength=USART_WordLength_8b;
USART_Init(USART1,&USART_InitStruct);


USART_ITConfig(USART1,USART_IT_RXNE,ENABLE);

NVIC_InitStruct.NVIC_IRQChannel=USART1_IRQn;
NVIC_InitStruct.NVIC_IRQChannelCmd=ENABLE;
NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority=2;
NVIC_InitStruct.NVIC_IRQChannelSubPriority=2;

NVIC_Init(&NVIC_InitStruct);
USART_Cmd(USART3,ENABLE);

#ifndef _tx_H_
#define _tx_H_
#include "stm32f4xx_gpio.h"
#include "stm32f4xx_rcc.h"
#include "stm32f4xx_tim.h"
#include "misc.h"
void USART3_Init(void);
void USART3_Sendstr(uint8_t* pData , uint8_t len);
void USART_IRQHandler(void);
#endif