[求助] 串口测试

林晓松 2013-12-20 13:20 楼主

各位大神，本人刚学习嵌入式，在测试串口程序时，想通过无线模块来接收和发送数据，模块的波特率是19200，固定的了，不知道以下这个程序怎么修改波特率？改来改去都没效果。
# include
# include
# include
# include
# include
# include
# include
# include
# include
static void Error(const char *Msg)
{
fprintf (stderr, "%s\n", Msg);
fprintf (stderr, "strerror() is %s\n", strerror(errno));
exit(1);
}
static void Warning(const char *Msg)
{
   fprintf (stderr, "Warning: %s\n", Msg);
}

static int SerialSpeed(const char *SpeedString)
{
int SpeedNumber = atoi(SpeedString);
# define TestSpeed(Speed) if (SpeedNumber == Speed) return B##Speed
TestSpeed(1200);
TestSpeed(2400);
TestSpeed(4800);
TestSpeed(9600);
TestSpeed(19200);
TestSpeed(38400);
TestSpeed(57600);
TestSpeed(115200);
TestSpeed(230400);
Error("Bad speed");
return -1;
}
static void PrintUsage(void)
{
fprintf(stderr, "comtest - interactive program of comm port\n");
fprintf(stderr, "press [ESC] 3 times to quit\n\n");
fprintf(stderr, "Usage: comtest [-d device] [-t tty] [-s speed] [-7] [-c] [-x] [-o] [-h]\n");
fprintf(stderr, "       -7 7 bit\n");
fprintf(stderr, "       -x hex mode\n");
fprintf(stderr, "       -o output to stdout too\n");
fprintf(stderr, "       -c stdout output use color\n");
fprintf(stderr, "       -h print this help\n");
exit(-1);
}
static inline void WaitFdWriteable(int Fd)
{
fd_set WriteSetFD;
FD_ZERO(&WriteSetFD);
FD_SET(Fd, &WriteSetFD);
if (select(Fd + 1, NULL, &WriteSetFD, NULL, NULL) < 0) {
Error(strerror(errno));
}

}
int main(int argc, char **argv)
{
int CommFd, TtyFd;
struct termios TtyAttr;
struct termios BackupTtyAttr;
int DeviceSpeed = B115200;
int TtySpeed = B115200;
int ByteBits = CS8;
const char *DeviceName = "/dev/ttyS0";
const char *TtyName = "/dev/tty";
int OutputHex = 0;
int OutputToStdout = 0;
int UseColor = 0;
opterr = 0;
for (;;) {
      int c = getopt(argc, argv, "d:s:t:7xoch");
      if (c == -1)
         break;
      switch(c) {
      case 'd':
         DeviceName = optarg;
         break;
      case 't':
         TtyName = optarg;
         break;
      case 's':
   if (optarg[0] == 'd') {
  DeviceSpeed = SerialSpeed(optarg + 1);
   } else if (optarg[0] == 't') {
  TtySpeed = SerialSpeed(optarg + 1);
   } else
         TtySpeed = DeviceSpeed = SerialSpeed(optarg);
         break;
case 'o':
   OutputToStdout = 1;
   break;
case '7':
   ByteBits = CS7;
   break;
      case 'x':
         OutputHex = 1;
         break;
case 'c':
   UseColor = 1;
   break;
      case '?':
      case 'h':
      default:
   PrintUsage();
      }
}
if (optind != argc)
      PrintUsage();
CommFd = open(DeviceName, O_RDWR, 0);
if (CommFd < 0)
Error("Unable to open device");
if (fcntl(CommFd, F_SETFL, O_NONBLOCK) < 0)
   Error("Unable set to NONBLOCK mode");

memset(&TtyAttr, 0, sizeof(struct termios));
TtyAttr.c_iflag = IGNPAR;
TtyAttr.c_cflag = DeviceSpeed | HUPCL | ByteBits | CREAD | CLOCAL;
TtyAttr.c_cc[VMIN] = 1;
if (tcsetattr(CommFd, TCSANOW, &TtyAttr) < 0)
      Warning("Unable to set comm port");
TtyFd = open(TtyName, O_RDWR | O_NDELAY, 0);
if (TtyFd < 0)
Error("Unable to open tty");
TtyAttr.c_cflag = TtySpeed | HUPCL | ByteBits | CREAD | CLOCAL;
if (tcgetattr(TtyFd, &BackupTtyAttr) < 0)
Error("Unable to get tty");
if (tcsetattr(TtyFd, TCSANOW, &TtyAttr) < 0)
Error("Unable to set tty");

for (;;) {
unsigned char Char = 0;
fd_set ReadSetFD;
void OutputStdChar(FILE *File) {
   char Buffer[10];
   int Len = sprintf(Buffer, OutputHex ? "%.2X  " : "%c", Char);
   fwrite(Buffer, 1, Len, File);
}
FD_ZERO(&ReadSetFD);
FD_SET(CommFd, &ReadSetFD);
FD_SET( TtyFd, &ReadSetFD);
# define max(x,y) ( ((x) >= (y)) ? (x) : (y) )
if (select(max(CommFd, TtyFd) + 1, &ReadSetFD, NULL, NULL, NULL) < 0) {
   Error(strerror(errno));
}
# undef max
if (FD_ISSET(CommFd, &ReadSetFD)) {
   while (read(CommFd, &Char, 1) == 1) {
  WaitFdWriteable(TtyFd);
  if (write(TtyFd, &Char, 1) < 0) {
      Error(strerror(errno));
  }
  if (OutputToStdout) {
   if (UseColor)
fwrite("\x1b[01;34m", 1, 8, stdout);
   OutputStdChar(stdout);
   if (UseColor)
fwrite("\x1b[00m", 1, 8, stdout);
   fflush(stdout);
  }
   }
}
if (FD_ISSET(TtyFd, &ReadSetFD)) {
   while (read(TtyFd, &Char, 1) == 1) {
      static int EscKeyCount = 0;
  WaitFdWriteable(CommFd);
      if (write(CommFd, &Char, 1) < 0) {
      Error(strerror(errno));
  }
  if (OutputToStdout) {
   if (UseColor)
fwrite("\x1b[01;31m", 1, 8, stderr);
   OutputStdChar(stderr);
   if (UseColor)
fwrite("\x1b[00m", 1, 8, stderr);
   fflush(stderr);
      }
      if (Char == '\x1b') {
                  EscKeyCount ++;
                  if (EscKeyCount >= 3)
                     goto ExitLabel;
            } else
                  EscKeyCount = 0;
   }
      }
}
ExitLabel:
if (tcsetattr(TtyFd, TCSANOW, &BackupTtyAttr) < 0)
Error("Unable to set tty");
return 0;
}