该代码可以在freertos中正常运行，你可以进行更多细节优化
PA9(TX)
PA10(RX)
#include "usart.h"// 解决串口死机问题
#pragma import(__use_no_semihosting)
struct __FILE { int handle; }; // 标准库需要的支持函数
FILE __stdout; // FILE 在stdio.h文件
void _sys_exit(int x) { x = x; } // 定义_sys_exit()以避免使用半主机模式//串口1中断服务程序
u8 USART1_RX_BUF[USART_REC_LEN]; //接收缓冲,最大USART_REC_LEN个字节.
u16 USART1_RX_STA=0; //接收状态标记 //串口2中断服务程序
u8 USART2_RX_BUF[USART_REC_LEN]; //接收缓冲,最大USART_REC_LEN个字节.
u16 USART2_RX_STA=0; //接收状态标记
//初始化IO 串口1
//bound:波特率
void usart1_init(u32 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.9GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; //PA.9GPIO_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;//PA10GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;//上拉GPIO_Init(GPIOA, &GPIO_InitStructure);//初始化GPIOA.10 //Usart1 NVIC 配置NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority= 2 ;//抢占优先级3NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //子优先级0NVIC_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_Init(USART1, &USART_InitStructure); //初始化串口1USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//开启串口接受中断USART_Cmd(USART1, ENABLE); //使能串口1
}//重定义fputc函数
int fputc(int ch, FILE *f) // 重定向fputc函数，使printf的输出，由fputc输出到UART, 这里使用串口1(USART1)
{ //if(xFlag.PrintfOK == 0) return 0; // 判断USART是否已配置，防止在配置前调用printf被卡死while((USART1->SR&0X40)==0); // 等待上一次串口数据发送完成 USART1->DR = (u8) ch; // 写DR,串口1将发送数据 return ch;
}//串口1中断服务程序
void USART1_IRQHandler(void)
{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if((USART1_RX_STA & 0x8000) == 0) //接收未完成{if(USART1_RX_STA & 0x4000) //接收到了0x0d{if(Res != 0x0a) USART1_RX_STA = 0; //接收错误,重新开始else {USART1_RX_STA |= 0x8000; //接收完成了 // 当接收完成后，将接收到的数据返回给 PCfor (u16 i = 0; i < (USART1_RX_STA & 0x3FFF); i++) {printf("%c", USART1_RX_BUF[i]);}// 提示接收成功printf("\rReceive Success!\r\n");// 清空接收缓冲区和状态USART1_RX_STA = 0;}}else //还没收到0X0D{ if(Res == 0x0d) USART1_RX_STA |= 0x4000;else{USART1_RX_BUF[USART1_RX_STA & 0x3FFF] = Res;USART1_RX_STA++;if(USART1_RX_STA > (USART_REC_LEN - 1)) USART1_RX_STA = 0; //接收数据错误,重新开始接收 } }} USART_ClearITPendingBit(USART1, USART_IT_RXNE); //清除中断标志位}
}/ USART 2 ///void usart2_init(u32 bound){//GPIO端口设置GPIO_InitTypeDef GPIO_InitStructure;USART_InitTypeDef USART_InitStructure;NVIC_InitTypeDef NVIC_InitStructure;RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE); // 使能 USART2 时钟RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE); // 使能 GPIOA 时钟//USART1_TX GPIOA.2GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2; //PA.2GPIO_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);//USART1_RX GPIOA.3初始化GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;//PA3GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;//上拉GPIO_Init(GPIOA, &GPIO_InitStructure);//Usart1 NVIC 配置NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority= 3 ;//抢占优先级3NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //子优先级0NVIC_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_Init(USART2, &USART_InitStructure); //初始化串口2USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);//开启串口接受中断USART_Cmd(USART2, ENABLE); //使能串口2
}//串口2中断服务程序
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); //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 // 当接收完成后，将接收到的数据返回给 PCfor (u16 i = 0; i < (USART2_RX_STA & 0x3FFF); i++) {printf("%c", USART2_RX_BUF[i]);}// 提示接收成功printf("\rReceive Success!\r\n");// 清空接收缓冲区和状态USART2_RX_STA = 0;}}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 > (USART_REC_LEN - 1)) USART2_RX_STA = 0; //接收数据错误,重新开始接收 } }} USART_ClearITPendingBit(USART2, USART_IT_RXNE); //清除中断标志位}
}#ifndef __USART_H
#define __USART_H
#include "stdio.h"
#include "stm32f10x.h"#define USART_REC_LEN 200 //定义最大接收字节数 200extern u8 USART_RX_BUF[USART_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 usart1_init(u32 bound);extern u16 USART2_RX_STA; //接收状态标记 void usart2_init(u32 bound);
#endif
