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 //´®¿ú1öð¶ï·þîñ³ìðò
 34 //×¢òâ,¶áè¡usartx->sräü±üãâäªãûæäãîµä´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)  //½óêõöð¶ï(½óêõµ½µäêý¾ý±øðëêç0x0d 0x0a½áî²)
 49     {
 50         res =usart_receivedata(usart1);//(usart1->dr);    //¶á衽óêõµ½µäêý¾ý
 51         
 52         if((usart_rx_sta&0x8000)==0)//½óêõî´íê³é
 53             {
 54             if(usart_rx_sta&0x4000)//½óêõµ½áë0x0d
 55                 {
 56                 if(res!=0x0a)usart_rx_sta=0;//½óêõ´íîó,öøð⿪ê¼
 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,öøð⿪꼽óêõ      
 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);    //ê¹äüusart1£¬gpioaê±öó
 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); //³õê¼»¯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);  //³õê¼»¯pa10
100     usart_initstructure.usart_baudrate = 9600;//ò»°ãéèöãîª9600;
101     usart_initstructure.usart_wordlength = usart_wordlength_8b;//×ö³¤îª8î»êý¾ý¸ñê½
102     usart_initstructure.usart_stopbits = usart_stopbits_1;//ò»¸öí£ö¹î»
103     usart_initstructure.usart_parity = usart_parity_no;//îþææå¼ð£ñéî»
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); //³õê¼»¯´®¿ú
108 #if en_usart1_rx          //èç¹ûê¹äüáë½óêõ  
109    //usart1 nvic åäöã
110   nvic_initstructure.nvic_irqchannel = usart1_irqn;
111     nvic_initstructure.nvic_irqchannelpreemptionpriority=3 ;//çàõ¼óåï輶3
112     nvic_initstructure.nvic_irqchannelsubpriority = 3;        //×óóåï輶3
113     nvic_initstructure.nvic_irqchannelcmd = enable;            //irqí¨µàê¹äü
114     nvic_init(&nvic_initstructure);    //¸ù¾ýö¸¶¨µä²îêý³õê¼»¯vic¼ä´ææ÷
115    
116   usart_itconfig(usart1, usart_it_rxne, enable);//¿ªæôöð¶ï
117 #endif
118   usart_cmd(usart1, enable);                    //ê¹äü´®¿ú 
119 
120 }

 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       

 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                         }