usart2.c usart2.h main.c代码如下：
//---------usart2.c文件-----------------------------------------------------------------------------------------------------------------------------------//
//初始化IO 串口2
#include "delay.h"
#include "usart3.h"
#include "stdarg.h"
#include "stdio.h"
#include "string.h"
//串口发送缓存区
__align(8) u8 USART2_TX_BUF[USART2_MAX_SEND_LEN]; //发送缓冲,最大USART2_MAX_SEND_LEN字节
#ifdef USART2_RX_EN //如果使能了接收
//串口接收缓存区
u8 USART2_RX_BUF[USART2_MAX_RECV_LEN]; //接收缓冲,最大USART2_MAX_RECV_LEN个字节.
u16 USART2_RX_STA = 0;
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);//(USART1->DR); //读取接收到的数据
if((USART2_RX_STA&0x8000)==0)//接收未完成
{
if(USART2_RX_STA&0x4000)//接收到了0x0d
{
if(res!=0x0a)USART2_RX_STA=0;//接收错误,重新开始
else USART2_RX_STA|=0x8000; //接收完成了
}
else //还没收到0X0D
{
if(res==0x0d)USART2_RX_STA|=0x4000;
else
{
USART2_RX_BUF[USART2_RX_STA&0X3FFF]=res ;
USART2_RX_STA++;
if(USART2_RX_STA>(USART2_MAX_RECV_LEN-1))USART2_RX_STA=0;//接收数据错误,重新开始接收
}
}
}
}
}
#endif
//bound:波特率
void usart2_init(u32 bound)
{
NVIC_InitTypeDef NVIC_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
//1.串口时钟和和GPIO时钟使能。
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA,ENABLE); //使能GPIOA时钟
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);//使能USART2时钟
//2.设置引脚复用器映射
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
//3.GPIO端口模式设置
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2 | GPIO_Pin_3; //GPIOA2和GPIOA3初始化
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GPIOA2，和GPIOA3
//4.串口参数初始化：设置波特率，字长，奇偶校验等参数
USART_InitStructure.USART_BaudRate = bound;//波特率一般设置为9600;
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2参数
//5.初始化NVIC
NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0 ;//抢占优先级0
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
//6.开启中断
USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);//开启中断
//7.使能串口
USART_Cmd(USART2, ENABLE); //使能串口
}
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