stm32怎么实现串口通讯

stm32怎么实现串口通讯,初学stm32，利用串口实现与单片机的发送和接收数据不会使用，还请各位大佬帮帮忙。。。。。,发不了文件啊，要重定向printf函数,网上有很多资料和例程，要学会查找资料和思考，买一个STM32的开发板，最好是资料丰富，售后支持好的，对照资料一步步学，很容易实现的。,找对应STM型号，了解简单的例程就行,

Angle145 发表于 2018-7-7 18:39

发不了文件啊，要重定向printf函数

用到printf函数才需要重定向，直接用串中发送字节并不需要重定向，,你有51基础吗？Stm32和51不同的就只有中断函的书写方式，51是在函数体后加中断号来决定中断服务程序，而Stm32的中断函数是固定死的，中断函数名字在启动文件(汇编)里就定义好了，所以要使用stm32的串口只需要初使化对应的串口的引脚成输出和输入，并且打开引脚复用时钟，然后再配置串口控制寄存器(配置波特率停止位数据位奇偶校验等)，其实这些都是死的，像模版一样记住就行。,/*************************USART串口*****************************************/
#define PRINTF_COM USART1 //printf打印串口选择可选：USART1、USART2、USART3、UART4、UART5

#pragma import(__use_no_semihosting)
struct __FILE
{
int handle;
};
FILE __stdout;
void _sys_exit(int x)
{
x = x;
}
int fputc(int ch, FILE *f)
{
OS_ENTER_CRITICAL();
USART_SendData(USART1, (uint8_t) ch);
while (USART_GetFlagStatus(USART1, USART_FLAG_TC) != SET);
OS_EXIT_CRITICAL();
return ch;
}

void USART_SendByte(USART_TypeDef *USART_COM,u8 c) //串口发送一个字节
{
while((USART_COM->SR&0X40)==0);//循环发送,直到发送完毕
USART_COM->DR = (u8)(c);
while((USART_COM->SR&0X40)==0);//循环发送,直到发送完毕
}

void USART_SendString(USART_TypeDef *USART_COM,unsigned char *s) //串口发送字符串函数
{
while(*s)
{
while((USART_COM->SR&0X40)==0);//循环发送,直到发送完毕
USART_COM->DR = (u8)(*s);
while((USART_COM->SR&0X40)==0);//循环发送,直到发送完毕
s++;
}
}

void USART_SendBuf(USART_TypeDef *USART_COM,unsigned char *buf,u16 len) //串口发送数组函数
{
while(len–)
{
while((USART_COM->SR&0X40)==0);//循环发送,直到发送完毕
USART_COM->DR = (u8)(*buf++);
while((USART_COM->SR&0X40)==0);//循环发送,直到发送完毕
}
}

void USART1_Config(u32 BaudRate)  //串口1初始化函数
{
  GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;

//使能USART1，GPIOA时钟
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA, ENABLE);

//GPIO端口设置
//USART1_TX GPIOA.9初始化
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;       //PA.9
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;    //复用推挽输出
  GPIO_Init(GPIOA, &GPIO_InitStructure);          //初始化GPIOA.9

  //USART1_RX    GPIOA.10初始化
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;//PA10
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//浮空输入
  GPIO_Init(GPIOA, &GPIO_InitStructure);//初始化GPIOA.10

//USART 初始化设置
USART_InitStructure.USART_BaudRate = BaudRate;//串口波特率
USART_InitStructure.USART_WordLength = USART_WordLength_8b;//字长为8位数据格式
USART_InitStructure.USART_StopBits = USART_StopBits_1;//一个停止位
USART_InitStructure.USART_Parity = USART_Parity_No;//无奇偶校验位
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//无硬件数据流控制
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx; //收发模式

  USART_Init(USART1, &USART_InitStructure);    //初始化串口1

//Usart1 NVIC 配置
  NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//抢占优先级3
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //子优先级3
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道使能
NVIC_Init(&NVIC_InitStructure); //根据指定的参数初始化VIC寄存器

USART_ClearFlag(USART1,USART_FLAG_TC);
  USART_ITConfig(USART1, USART_IT_RXNE, ENABLE); //开启串口接受中断
  USART_Cmd(USART1, ENABLE);                   //使能串口1
}

void USART2_Config(u32 BaudRate)  //串口2初始化函数
{
  GPIO_InitTypeDef GPIO_InitStructure;
  USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;

//时钟使能
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);//使能GPIOA,D时钟
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);//使能USART2时钟

//GPIO端口设置
//TX
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;             //PA2
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;       //复用推挽
  GPIO_Init(GPIOA, &GPIO_InitStructure);

//RX
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;          //PA3
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; //浮空输入
  GPIO_Init(GPIOA, &GPIO_InitStructure);

RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART2,ENABLE); //复位串口2
RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART2,DISABLE); //停止复位

USART_InitStructure.USART_BaudRate = BaudRate;                //波特率设置
USART_InitStructure.USART_WordLength = USART_WordLength_8b;  //8位数据长度
USART_InitStructure.USART_StopBits = USART_StopBits_1;    //一个停止位
USART_InitStructure.USART_Parity = USART_Parity_No;       ///奇偶校验位
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//无硬件数据流控制
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;//收发模式

USART_Init(USART2, &USART_InitStructure); //初始化串口
USART_ClearFlag(USART2,USART_FLAG_TC);

//中断
NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn; //使能串口2中断
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 3; //先占优先级2级
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //从优先级2级
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //使能外部中断通道
NVIC_Init(&NVIC_InitStructure); //根据NVIC_InitStruct中指定的参数初始化外设NVIC寄存器

USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);//开启中断

USART_Cmd(USART2, ENABLE); //使能串口
}

void USART3_Config(u32 BaudRate) //串口3初始化函数
{
NVIC_InitTypeDef NVIC_InitStructure;
GPIO_InitTypeDef  GPIO_InitValue;
USART_InitTypeDef USART_InitValue;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO|RCC_APB2Periph_GPIOB, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3,ENABLE);

//GPIO端口设置
GPIO_InitValue.GPIO_Pin=GPIO_Pin_10;
GPIO_InitValue.GPIO_Speed=GPIO_Speed_50MHz;
GPIO_InitValue.GPIO_Mode=GPIO_Mode_AF_PP;
GPIO_Init(GPIOB,&GPIO_InitValue);

  GPIO_InitValue.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_InitValue.GPIO_Pin =GPIO_Pin_11;
  GPIO_Init(GPIOB,&GPIO_InitValue);

USART_InitValue.USART_BaudRate = BaudRate;
  USART_InitValue.USART_WordLength = USART_WordLength_8b;
  USART_InitValue.USART_StopBits = USART_StopBits_1;
  USART_InitValue.USART_Parity = USART_Parity_No;
  USART_InitValue.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
  USART_InitValue.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;

  USART_Init(USART3,&USART_InitValue);
USART_ClearFlag(USART3,USART_FLAG_TC);
USART_ITConfig(USART3,USART_IT_RXNE,ENABLE);//配置串口接收非空中断

  NVIC_InitStructure.NVIC_IRQChannel =USART3_IRQn ;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority =3; //抢占优先级3
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //子优先级3
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //使能USART3中断
  NVIC_Init(&NVIC_InitStructure);

  USART_Cmd(USART3,ENABLE);
}

void UART4_Config(u32 BaudRate)    //串口4初始化函数
{
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC,ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);
//注意UART4是挂载在APB1总线上的，用RCC_APB1PeriphClockCmd()函数初始化！
RCC_APB1PeriphClockCmd(RCC_APB1Periph_UART4,ENABLE);

//GPIO端口设置
//UART4_TX PC.10
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;    //将UART4 的TX 配置为复用推挽输出 AF_PP
GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz; //输出速度50MHz
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP; //推挽输出模式 Out_PP
GPIO_Init(GPIOC, &GPIO_InitStructure);

//将UART4 的RX 配置为复用浮空输入 IN_FLOATING
//UART4_RX    PC.11
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_IN_FLOATING; //浮空输入 IN_FLOATING
GPIO_Init(GPIOC, &GPIO_InitStructure);

//UART4配置 N 8 1
USART_InitStructure.USART_BaudRate = BaudRate; //波特率
USART_InitStructure.USART_WordLength = USART_WordLength_8b; //字长8位
USART_InitStructure.USART_StopBits = USART_StopBits_1; //1位停止字节
USART_InitStructure.USART_Parity = USART_Parity_No; //无奇偶校验
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None; //无流控制
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx; //打开Rx接收和Tx发送功能
USART_Init(UART4 , &USART_InitStructure);

//UART4 NVIC 配置
NVIC_InitStructure.NVIC_IRQChannel = UART4_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//抢占优先级3
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //子优先级3
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道使能
NVIC_Init(&NVIC_InitStructure); //根据指定的参数初始化VIC寄存器
USART_ClearFlag(UART4,USART_FLAG_TC);
USART_ITConfig(UART4,USART_IT_RXNE,ENABLE);//配置串口接收非空中断

USART_Cmd(UART4,ENABLE);
}

void UART5_Config(u32 BaudRate) //串口5初始化函数
{
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO|RCC_APB2Periph_GPIOC|RCC_APB2Periph_GPIOD, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_UART5,ENABLE);

//GPIO端口设置
//UART5_TX PC.12
GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz; //输出速度50MHz
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP; //推挽输出模式 Out_PP
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;    //将UART4 的TX 配置为复用推挽输出 AF_PP
GPIO_Init(GPIOC, &GPIO_InitStructure);

//将UART5 的RX 配置为复用浮空输入 IN_FLOATING
//UART5_RX    PD.2
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_IN_FLOATING; //浮空输入 IN_FLOATING
GPIO_Init(GPIOD, &GPIO_InitStructure);

USART_InitStructure.USART_BaudRate = BaudRate; //波特率
USART_InitStructure.USART_WordLength = USART_WordLength_8b; //字长8位
USART_InitStructure.USART_StopBits = USART_StopBits_1; //1位停止字节
USART_InitStructure.USART_Parity = USART_Parity_No; //无奇偶校验
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None; //无流控制
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx; //打开Rx接收和Tx发送功能

USART_Init(UART5 , &USART_InitStructure);

/* Enable the UART5 Interrupt */
NVIC_InitStructure.NVIC_IRQChannel = UART5_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//抢占优先级3
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //子优先级3
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道使能
NVIC_Init(&NVIC_InitStructure); //根据指定的参数初始化VIC寄存器

USART_ClearFlag(UART5,USART_FLAG_TC);
USART_ITConfig(UART5,USART_IT_RXNE,ENABLE);//配置串口接收非空中断

USART_Cmd(UART5,ENABLE);
}
/*******************************串口END***************************************/
//串口1中断函数
void USART1_IRQHandler(void)             //串口1中断服务程序
{
u8 res;
if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)  //接收中断(接收到的数据必须是0x0d 0x0a结尾)
{
res =USART_ReceiveData(USART1); //读取接收到的数据
USART_SendData(USART1,res);
}
}

//串口2中断函数
void USART2_IRQHandler(void)
{
u8 res;
if(USART_GetITStatus(USART2, USART_IT_RXNE) != RESET) //接收到数据
{
res =USART_ReceiveData(USART2); //读取接收到的数据
USART_SendData(USART2,res);
}
}

//串口3中断函数
void USART3_IRQHandler(void)
{
u8 res;
if(USART_GetITStatus(USART3, USART_IT_RXNE) != RESET) //接收到数据
{
res =USART_ReceiveData(USART3); //读取接收到的数据
USART_SendData(USART3,res);
}
}

//串口4中断函数
void UART4_IRQHandler(void)
{
u8 res;
if(USART_GetITStatus(UART4, USART_IT_RXNE) != RESET) //接收到数据
{
res =USART_ReceiveData(UART4); //读取接收到的数据
USART_SendData(UART4,res);
}
}

//串口5中断函数
void UART5_IRQHandler(void)
{
u8 res;
if(USART_GetITStatus(UART5, USART_IT_RXNE) != RESET) //接收到数据
{
res =USART_ReceiveData(UART5); //读取接收到的数据
USART_SendData(UART5,res);
}
}
//注：中断函数名是固定的，不能更改(可在启动文件里更改,不建议更改),
//串口使用方法：想要哪个串口就初使化哪个串口，然后用发送函数就可以发送数据，当然，这里提供了printf重定向了，你也可以直接用printf函数发送。
//使用示例：
int main(void)
{
USART1_Config(9600);  //初使化串口1，波特率为9600
  while(1)
  {
   printf(“你好！ \r\n”);  //\r\n是回车符
  }
}
//接收串口数据在串口1中断函数里接收，和51一样。
//串口1  引脚: PA9: TXD  PA10:RXD
//串口2  引脚: PA2: TXD  PA3: RXD
//串口3  引脚: PB10:TXD  PB11:RXD
//串口4  引脚: PC10:TXD  PC11:RXD
//串口5  引脚: PC12:TXD  PD2: RXD