Stm32F407ZGT6 串口通迅 usart2

正点原子的开发板，一定要注意跳线帽

串口2

usart2.h

//STM32F407 zgt6 串口2
#ifndef __USART2_H
#define __USART2_H
#include "sys.h" 

#define USART2_MAX_RECV_LEN 200
#define USART2_MAX_SEND_LEN 200
extern u8 USART2_RX_buf[USART2_MAX_RECV_LEN];
extern u8 USART2_TX_buf[USART2_MAX_SEND_LEN];
extern u16 USART2_RX_STA;       //接收状态标记
void uart2_init(u32 bound);
#endif

usart2.c

#include "usart2.h"

u8 USART2_RX_buf[USART2_MAX_RECV_LEN];
u8 USART2_TX_buf[USART2_MAX_SEND_LEN];
u16 USART2_RX_STA=0;//接收状态标记
/* 初始化串口过程
1.串口时钟使能
2.设置引脚复用
3.GPIO端口初始化
4.串口参数初始化
5.初始化NVIC并且开启中断2
6.使能串口

*/
//初始化IO 串口2 
//bound:波特率
void uart2_init(u32 bound)
{
   //GPIO端口设置
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA,ENABLE); //使能GPIOA时钟
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);//使能USART2时钟 
 
//串口1对应引脚复用映射
GPIO_PinAFConfig(GPIOA,GPIO_PinSource2,GPIO_AF_USART2); //GPIOA2复用为USART2
GPIO_PinAFConfig(GPIOA,GPIO_PinSource3,GPIO_AF_USART2); //GPIOA3复用为USART2

//USART2端口配置
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2 | GPIO_Pin_3; //GPIOA2与GPIOA3
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//复用功能
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //速度50MHz
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽复用输出
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; //上拉
GPIO_Init(GPIOA,&GPIO_InitStructure); //初始化PA2，PA3


   //USART2 初始化设置
USART_InitStructure.USART_BaudRate = bound;//波特率设置
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(USART2, &USART_InitStructure); //初始化串口2

NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;//串口2中断通道
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3;//抢占优先级3 数值越小优先级越高
NVIC_InitStructure.NVIC_IRQChannelSubPriority =3; //子优先级3,响应优先级
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_ITConfig(USART2, USART_IT_RXNE, ENABLE);//开启接收中断
USART_Cmd(USART2, ENABLE);  //使能串口2

}




void USART2_IRQHandler(void)
{
u8 Res;
if(USART_GetITStatus(USART2, USART_IT_RXNE) != RESET)  //接收中断(接收到的数据必须是0x0d 0x0a结尾)
{
Res =USART_ReceiveData(USART2);//(USART2->DR); //读取接收到的数据
USART_SendData(USART2,Res);//将收到的发回去了
  } 

}


main.c

#include "sys.h"
#include "delay.h"
//#include "usart1.h"
#include "usart2.h"
#include "led.h"




int main(void)
{
u8 t=0,len=0;
u16 times=0;
char str[]={'u','1','w','a','i','t','\r','\n'};
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
delay_init(168);//168 MHz
LED_Init();
LED1=0;//位带操作点灯 sys.h
uart2_init(115200);
while(1)
{

if (USART2_RX_STA&0x8000)//接收完成
{
len=USART2_RX_STA&0x3fff;//长度不能超255,因为len是u8
for(t=0;t{
USART2->DR=USART2_RX_buf[t];
while((USART2->SR & 0x40)==0);//等待发送结束
USART2_RX_STA=0;
}

}
else
{
times++;
if(times %500==0)//5sec
{
for(t=0;t{
USART2->DR=str[t];
while((USART2->SR & 0x40)==0);//等待发送结束
}
LED1=!LED1;
}
delay_ms(10);

}
}
}




以上必须在模板工程的配置情况下才能运行,本人验证以上代码ok