stm32F103片上串口USART1通信实验

硬件说明：如原理图所示，

103的PA10 PA11分别接CP2102usb转串口芯片的TXD RXD引脚。CP2102芯片是将串口和电脑USB接口进行了转接，方便应用灵活。

片上串口驱动代码如下。

  1 #include "usart.h"    
  2 #include "stm32f10x_usart.h"
  3 
  4 #if SYSTEM_SUPPORT_UCOS
  5 #include "includes.h"    //ucos 
  6 #endif
  7 
  8 #if 1
  9 #pragma import(__use_no_semihosting)             
 10                
 11 struct __FILE 
 12 { 
 13     int handle; 
 14 
 15 }; 
 16 
 17 FILE __stdout;         
 18 _sys_exit(int x) 
 19 { 
 20     x = x; 
 21 } 
 22 
 23 int fputc(int ch, FILE *f)
 24 {      
 25         while(USART_GetFlagStatus(USART1,USART_FLAG_TC)==RESET); 
 26     USART_SendData(USART1,(uint8_t)ch);   
 27       return ch;
 28 }
 29 #endif 
 30 
 31 
 32 #if EN_USART1_RX   
 33 //´®¿Ú1ÖжϷþÎñ³ÌÐò
 34 //×¢Òâ,¶ÁÈ¡USARTx->SRÄܱÜÃâĪÃûÆäÃîµÄ´íÎó       
 35 u8 USART_RX_BUF[USART_REC_LEN];  //½ÓÊÕ»º³å,×î´óUSART_REC_LEN¸ö×Ö½Ú.
 36 
 37 
 38 
 39 u16 USART_RX_STA=0;       //Receiving status marker
 40   
 41 void USART1_IRQHandler(void)
 42 {
 43     
 44     u8 res;    
 45 #ifdef OS_CRITICAL_METHOD     
 46     OSIntEnter();    
 47 #endif
 48     if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)  //½ÓÊÕÖжÏ(½ÓÊÕµ½µÄÊý¾Ý±ØÐëÊÇ0x0d 0x0a½áβ)
 49     {
 50         res =USART_ReceiveData(USART1);//(USART1->DR);    //¶ÁÈ¡½ÓÊÕµ½µÄÊý¾Ý
 51         
 52         if((USART_RX_STA&0x8000)==0)//½ÓÊÕδÍê³É
 53             {
 54             if(USART_RX_STA&0x4000)//½ÓÊÕµ½ÁË0x0d
 55                 {
 56                 if(res!=0x0a)USART_RX_STA=0;//½ÓÊÕ´íÎó,ÖØпªÊ¼
 57                 else USART_RX_STA|=0x8000;    //½ÓÊÕÍê³ÉÁË 
 58                 }
 59             else //»¹Ã»ÊÕµ½0X0D
 60                 {    
 61                 if(res==0x0d)USART_RX_STA|=0x4000;
 62                 else
 63                     {
 64                     USART_RX_BUF[USART_RX_STA&0X3FFF]= res;
 65                     USART_RX_STA++;
 66                     if(USART_RX_STA>(USART_REC_LEN-1))USART_RX_STA=0;//½ÓÊÕÊý¾Ý´íÎó,ÖØпªÊ¼½ÓÊÕ      
 67                     }         
 68                 }
 69             }   
 70             
 71      } 
 72 #ifdef OS_CRITICAL_METHOD     
 73     OSIntExit();                                               
 74 #endif
 75 } 
 76 #endif                                         
 77 
 78 //A11 RX  A10 TX
 79 
 80 void uart_init()
 81 {
 82     
 83 
 84   GPIO_InitTypeDef GPIO_InitStructure;
 85     USART_InitTypeDef USART_InitStructure;
 86     NVIC_InitTypeDef NVIC_InitStructure;
 87      
 88     RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA, ENABLE);    //ʹÄÜUSART1£¬GPIOAʱÖÓ
 89   USART_DeInit(USART1);  //¸´Î»´®¿Ú1
 90 
 91     GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10; //PC.10
 92     GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
 93     GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;    //¸´ÓÃÍÆÍìÊä³ö
 94     GPIO_Init(GPIOA, &GPIO_InitStructure); //³õʼ»¯PA9
 95    
 96 
 97     GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
 98     GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//¸¡¿ÕÊäÈë
 99     GPIO_Init(GPIOA, &GPIO_InitStructure);  //³õʼ»¯PA10
100     USART_InitStructure.USART_BaudRate = 9600;//Ò»°ãÉèÖÃΪ9600;
101     USART_InitStructure.USART_WordLength = USART_WordLength_8b;//×Ö³¤Îª8λÊý¾Ý¸ñʽ
102     USART_InitStructure.USART_StopBits = USART_StopBits_1;//Ò»¸öֹͣλ
103     USART_InitStructure.USART_Parity = USART_Parity_No;//ÎÞÆæżУÑéλ
104     USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//ÎÞÓ²¼þÊý¾ÝÁ÷¿ØÖÆ
105     USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;    //ÊÕ·¢Ä£Ê½
106 
107     USART_Init(USART1, &USART_InitStructure); //³õʼ»¯´®¿Ú
108 #if EN_USART1_RX          //Èç¹ûʹÄÜÁ˽ÓÊÕ  
109    //Usart1 NVIC ÅäÖÃ
110   NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
111     NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//ÇÀÕ¼ÓÅÏȼ¶3
112     NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;        //×ÓÓÅÏȼ¶3
113     NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;            //IRQͨµÀʹÄÜ
114     NVIC_Init(&NVIC_InitStructure);    //¸ù¾ÝÖ¸¶¨µÄ²ÎÊý³õʼ»¯VIC¼Ä´æÆ÷
115    
116   USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//¿ªÆôÖжÏ
117 #endif
118   USART_Cmd(USART1, ENABLE);                    //ʹÄÜ´®¿Ú 
119 
120 }

c文件

 1 #ifndef __USART_H
 2 #define __USART_H
 3 #include "sys.h"
 4 #include "stdio.h"     
 5 
 6 //////////////////////////////////////////////////////////////////////////////////     
 7 #define USART_REC_LEN              200      
 8 #define EN_USART1_RX               1        
 9           
10 extern u8  USART_RX_BUF[USART_REC_LEN]; 
11 extern u16 USART_RX_STA;                 
12 
13 void uart_init();
14 
15 #endif       

h文件

 1                         #include "sys.h"
 2                         #include "usart.h"
 3                         #include "delay.h"
 4                         
 5 #define LED0 PAout(8)// DS0
 6 #define LED1 PBout(1)// DS1    
 7 #define LED2 PBout(3)// DS1
 8 #define LED3 PAout(11)// DS1    
 9 
10                         int main(void)
11                         {
12                             
13                         u8 t=0;
14                         u8 y=0;
15                         Stm32_Clock_Init(9); 
16                         delay_init(72); 
17                         uart_init(); 
18     
19                         while(1)
20                         {
21                         printf("t999:%d\n",t);
22                         delay_ms(1000);
23                         t++;
24                             if(y ==4)y=0;
25                             switch(y)
26                             {
27                                 case 0:  LED0 = 1;LED1 =0; LED2 =0; LED3=0;break;
28                                 case 1:     LED1 = 1;LED0 =0; LED2 =0; LED3=0; break;
29                                 case 2:  LED2 = 1;LED0 =0; LED1 =0; LED3=0;break;
30                                 case 3:     LED3 = 1;LED1 =0; LED0 =0; LED2=0;break;
31                             }
32                             y++;
33                         }
34 
35                         return 0;
36                         }

main