STM32F407串口接收并解码字符串
usart2.c
串口2初始化
void uart2_init(u32 bound)
{
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA,ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);
USART_OverSampling8Cmd(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 = bound;
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);
USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);
NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority =2;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
发送一个字符
void Usart_SendByte( USART_TypeDef * pUSARTx, uint8_t ch)
{
USART_SendData(pUSARTx,ch);
while (USART_GetFlagStatus(pUSARTx, USART_FLAG_TXE) == RESET);
}
发送字符串,不需要通过printf()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');
while(USART_GetFlagStatus(pUSARTx,USART_FLAG_TC)==RESET)
{}
}
串口中断函数,在中断函数内接收并解码字符串
void USART2_IRQHandler(void)
{
u8 Res;
u8 len;
static char USART2_RX_BUF[USART2_REC_LEN];
static u16 USART2_RX_STA=0;
if(USART_GetITStatus(USART2, USART_IT_RXNE) != RESET)
{
Res =USART_ReceiveData(USART2);
if((USART2_RX_STA&0x8000)==0)
{
if(USART2_RX_STA&0x4000)
{
if(Res==0x0a) USART2_RX_STA|=0x8000;
else USART2_RX_STA&=~0x8000;
}
else
{
if(Res==0x0d)USART2_RX_STA|=0x4000;
else
{
USART2_RX_BUF[USART2_RX_STA&0XFFF]=Res ;
USART2_RX_STA++;
if((USART2_RX_STA&0XFFF)>(USART2_REC_LEN-1)) USART2_RX_STA&=0xf000;
}
}
}
}
if(USART2_RX_STA&0x8000)
{
len=USART2_RX_STA&0xfff;
USART2_RX_STA=0;
USART2_RX_BUF[len]=0;
if(strcmp(USART2_RX_BUF,"power on")==0)
{
Usart_SendString( USART2,"LED ON\r\n");
}
if(strcmp(USART2_RX_BUF,"power off")==0)
{
Usart_SendString( USART2,"LED OFF\r\n");
}
}
}
1.上位机发送指令必须以\r\n结束符
2.单片机接收到“power on”,返回"LED ON\r\n";
接收到"power off",返回"LED OFF\r\n"。
usart2.h
#ifndef __USART2_H
#define __USART2_H
#include "firmware.h"
#include "stdio.h"
#define USART2_REC_LEN 100
#define USART2_TX_LEN 100
void uart2_init(u32 bound);
void Usart_SendByte( USART_TypeDef * pUSARTx, uint8_t ch);
void Usart_SendString( USART_TypeDef * pUSARTx, char *str);
#endif
附加使用pintf()重定义代码
#if 1
#pragma import(__use_no_semihosting)
struct __FILE
{
int handle;
};
FILE __stdout;
void _sys_exit(int x)
{
x = x;
}
int fputc(int ch, FILE *f)
{
while((USART2->SR&0X40)==0);
USART2->DR = (u8) ch;
return ch;
}
#endif
本文内容由网友自发贡献,版权归原作者所有,本站不承担相应法律责任。如您发现有涉嫌抄袭侵权的内容,请联系:hwhale#tublm.com(使用前将#替换为@)