serial communication
Schematic diagram of the internal structure of the UART serial port
Detailed introduction of Puzhong Technology
Interrupt knowledge supplement
the code
#ifndef __USART_H
#define __USART_H
#include "stdio.h"
#include "stm32f10x_usart.h"
#define USART1_REC_LEN 200 //定义最大接收字节数 200
extern u8 USART1_RX_BUF[USART1_REC_LEN]; //接收缓冲,最大USART_REC_LEN个字节.末字节为换行符
extern u16 USART1_RX_STA; //接收状态标记
void uart_init(unsigned int bound);
//stm32发送数据
void Usart_SendByte( USART_TypeDef * pUSARTx, uint8_t ch);
void Usart_SendString( USART_TypeDef * pUSARTx, char *str);
#endif#include "usart.h"
#include "stm32f10x.h"
u8 USART1_RX_BUF[USART1_REC_LEN]; //接收缓冲,最大USART_REC_LEN个字节.
//接收状态
//bit15， 接收完成标志
//bit14， 接收到0x0d
//bit13~0， 接收到的有效字节数目
u16 USART1_RX_STA=0; //接收状态标记
int fputc(int ch, FILE *f)
{
while((USART1->SR&0X40)==0);//循环发送,直到发送完毕
USART1->DR = (u8) ch;
return ch;
}
int fgetc(FILE *fp)
{
while(USART_GetFlagStatus(USART1, USART_FLAG_RXNE) != SET); //等待直到接收缓冲区内非空
return (int)USART_ReceiveData(USART1);
}
/* 发送一个字节 */
void Usart_SendByte( USART_TypeDef * pUSARTx, uint8_t ch)
{
/* 发送一个字节数据到USART */
USART_SendData(pUSARTx,ch);
/* 等待发送数据寄存器为空 */
while (USART_GetFlagStatus(pUSARTx, USART_FLAG_TXE) == RESET);
}
/* 发送字符串 */
void Usart_SendString( USART_TypeDef * pUSARTx, char *str)
{
unsigned int k=0;
do
{
Usart_SendByte( pUSARTx, *(str + k) );
k++;
} while(*(str + k)!='\0');
/* 等待发送完成 */
while(USART_GetFlagStatus(pUSARTx,USART_FLAG_TC)==RESET)
{}
}
/*******************************************************************************
* 函 数 名 : USART1_IRQHandler
* 函数功能 : USART1中断函数
* 输 入 : 无
* 输 出 : 无
*******************************************************************************/
void USART1_IRQHandler(void) //串口1中断服务程序
{
u8 r;
if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET) //接收中断
{
r =USART_ReceiveData(USART1);//(USART1->DR); //读取接收到的数据
if((USART1_RX_STA&0x8000)==0)//接收未完成
{
if(USART1_RX_STA&0x4000)//接收到了0x0d
{
if(r!=0x0a)USART1_RX_STA=0;//接收错误,重新开始
else USART1_RX_STA|=0x8000; //接收完成了
}
else //还没收到0X0D
{
if(r==0x0d)USART1_RX_STA|=0x4000;
else
{
USART1_RX_BUF[USART1_RX_STA&0X3FFF]=r;
USART1_RX_STA++;
if(USART1_RX_STA>(USART1_REC_LEN-1))USART1_RX_STA=0;//接收数据错误,重新开始接收
}
}
}
}
}
void uart_init(unsigned int bound){
//GPIO端口设置
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA, ENABLE); //使能USART1，GPIOA时钟
//USART1_TX GPIOA.9
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
//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 初始化设置
USART_InitStructure.USART_BaudRate = bound;//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_ClearFlag(USART1, USART_FLAG_TC);
USART_Init(USART1, &USART_InitStructure); //初始化串口1
USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//开启串口接受中断
USART_Cmd(USART1, ENABLE); //使能串口1
}
appendix:
[STM32F4] Four, serial communication 1 - hardware part (ngui.cc)
Puzhong STM32F1xx Development Strategy_V2.2--Standard Library Version.pdf
STM32 study notes (10) serial port UART_stm32uart_兔兔嘉.'s blog-CSDN blog
STM32-serial communication (serial receiving and sending) - Gu Yueju (guyuehome.com) (very good)