Linux tty串口測試程式

標籤：linux   arm   串口   

在程式中，很容易配置串口的屬性，這些屬性定義在結構體struct termios中。

關於termios的詳細介紹，可以另行查資料，或者參考：詳解linux下的串口通訊開發：http://blog.itpub.net/24790158/viewspace-1041147/

#include<stdio.h>#include<stdlib.h>#include<string.h>#include<sys/types.h>#include<sys/stat.h>#include<fcntl.h>#include<unistd.h>#include<termios.h>#include<string.h>int set_opt(int fd,int nSpeed, int nBits, char nEvent, int nStop){ struct termios newtio,oldtio; if  ( tcgetattr( fd,&oldtio)  !=  0) {  perror("SetupSerial 1");  return -1; } bzero( &newtio, sizeof( newtio ) ); newtio.c_cflag  |=  CLOCAL | CREAD; //CLOCAL:忽略modem控制線  CREAD：開啟接受者 newtio.c_cflag &= ~CSIZE; //字元長度掩碼。取值為：CS5，CS6，CS7或CS8 switch( nBits ) { case 7:  newtio.c_cflag |= CS7;  break; case 8:  newtio.c_cflag |= CS8;  break; } switch( nEvent ) { case 'O':  newtio.c_cflag |= PARENB; //允許輸出產生奇偶資訊以及輸入到同位  newtio.c_cflag |= PARODD;  //輸入和輸出是奇及校正  newtio.c_iflag |= (INPCK | ISTRIP); // INPACK:啟用輸入奇偶檢測；ISTRIP：去掉第八位  break; case 'E':  newtio.c_iflag |= (INPCK | ISTRIP);  newtio.c_cflag |= PARENB;  newtio.c_cflag &= ~PARODD;  break; case 'N':   newtio.c_cflag &= ~PARENB;  break; } switch( nSpeed ) { case 2400:  cfsetispeed(&newtio, B2400);  cfsetospeed(&newtio, B2400);  break; case 4800:  cfsetispeed(&newtio, B4800);  cfsetospeed(&newtio, B4800);  break; case 9600:  cfsetispeed(&newtio, B9600);  cfsetospeed(&newtio, B9600);  break; case 115200:  cfsetispeed(&newtio, B115200);  cfsetospeed(&newtio, B115200);  break; case 460800:  cfsetispeed(&newtio, B460800);  cfsetospeed(&newtio, B460800);  break; default:  cfsetispeed(&newtio, B9600);  cfsetospeed(&newtio, B9600);  break; } if( nStop == 1 )  newtio.c_cflag &=  ~CSTOPB; //CSTOPB:設定兩個停止位，而不是一個 else if ( nStop == 2 ) newtio.c_cflag |=  CSTOPB;  newtio.c_cc[VTIME]  = 0; //VTIME:非cannoical模式讀時的延時，以十分之一秒位單位 newtio.c_cc[VMIN] = 0; //VMIN:非canonical模式讀到最小字元數 tcflush(fd,TCIFLUSH); // 改變在所有寫入 fd 引用的對象的輸出都被傳輸後生效，所有已接受但未讀入的輸入都在改變發生前丟棄。 if((tcsetattr(fd,TCSANOW,&newtio))!=0) //TCSANOW:改變立即發生 {  perror("com set error");  return -1; } printf("set done!\n\r"); return 0;}int main(void){ int fd1,nset,nread,ret; char buf[100]={"test com data!...........\n"}; char buf1[100]; fd1 = open( "/dev/ttySAC0", O_RDWR); if (fd1 == -1)  exit(1); printf("open  SAC0 success!!\n"); nset = set_opt(fd1, 9600, 8, 'N', 1); if (nset == -1)  exit(1); printf("SET  SAC0 success!!\n"); printf("enter the loop!!\n"); while (1) {    memset(buf1, 0, sizeof(buf1));   ret = write(fd1, buf, 100);   if( ret > 0){      printf("write success!  wait data receive\n");   }   nread = read(fd1, buf1, 100);   if(nread > 0){printf("redatad: nread = %s\n\n\r", buf1);   }   sleep(1);  //nread = read(fd1, buf1,1);  //if(buf1[0] == 'q')   //break; } close(fd1); return 0;}

用arm-linux-gcc交叉編譯後在開發板上運行，將9口串口的2 3短接：

/ # ./com open  SAC0 success!!set done!SET  SAC0 success!!enter the loop!!write success!  wait data receivewrite success!  wait data receivewrite success!  wait data receivewrite success!  wait data receivewrite success!  wait data receivewrite success!  wait data receiveredatad: nread = test com data!...........write success!  wait data receiveredatad: nread = test com data!...........write success!  wait data receiveredatad: nread = test com data!...........

Linux tty串口測試程式