serial.cpp

/*========================================================================
    Serial.cc : Class wrapper for Serial I/O on Linux
  ------------------------------------------------------------------------
    Copyright (C) 1999-2002  James R. Bruce
    School of Computer Science, Carnegie Mellon University
  ------------------------------------------------------------------------
    This software is distributed under the GNU General Public License,
    version 2.  If you do not have a copy of this licence, visit
    www.gnu.org, or write: Free Software Foundation, 59 Temple Place,
    Suite 330 Boston, MA 02111-1307 USA.  This program is distributed
    in the hope that it will be useful, but WITHOUT ANY WARRANTY,
    including MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  ========================================================================*/

#ifndef WIN32
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <fcntl.h>
#include <cstdlib>
#include <cstdio>
#include <unistd.h>
#include <termios.h>
#include <string.h>
#else
# include <cstdlib>
# include <cstdio>
#endif

#include <QDebug>
#include "serial.h"

/**************************** TYPES ******************************************/

// #define RADIO_DEVICE "/dev/ttyS0"
namespace HAL
{
#ifndef WIN32
  const speed_t baud_rates[][2] =
  {
    {      B0,      0 },
    {     B50,     50 },
    {     B75,     75 },
    {    B110,    110 },
    {    B134,    134 },
    {    B150,    150 },
    {    B200,    200 },
    {    B300,    300 },
    {    B600,    600 },
    {   B1200,   1200 },
    {   B1800,   1800 },
    {   B2400,   2400 },
    {   B4800,   4800 },
    {   B9600,   9600 },
    {  B19200,  19200 },
    {  B38400,  38400 },
    {  B57600,  57600 },
    { B115200, 115200 },
    { B230400, 230400 },
    { B460800, 460800 }
  };

  /**************************** CODE *******************************************/


  /*
   * baud_rate_to_flag -
   *
   * convert from raw baud rate to teh
   * appropriate baud flag
   */
  speed_t baud_rate_to_flag(unsigned int speed)
  {
    int i;

    for (i = 0; i < 20; i++)
    {
      if (baud_rates[i][1] == speed)
        return(baud_rates[i][0]);
    }
    return 0;
  }


  /*
   * baud_flag_to_rate -
   *
   * This function converts from the speed s to
   * the baud flag
   */
  int baud_flag_to_rate(speed_t s)
  {
    int i;

    for(i = 0; i < 20; i++)
    {
      if (baud_rates[i][0] == s)
        return(baud_rates[i][1]);
    }
    return 0;
  }

#endif
  /**************************** SERIAL CLASS ***********************************/


  /*
   * open -
   *
   * This function opens the serial port device and configures it
   * to operate at the specified baud rate and parameters
   *
   * rETURN VALUE: TRUE on success, FALSE on failure
   */
  bool Serial::Open(const std::string& device, int baud)
  {
#ifdef WIN32
    DCB dcb;
    hCom = CreateFile( device.c_str(),
                       GENERIC_READ | GENERIC_WRITE,
                       0,    // exclusive access
                       NULL, // no security attributes
                       OPEN_EXISTING, 0, NULL);

    if (hCom == INVALID_HANDLE_VALUE)
    {
      err("ERROR: Can't open com port %s", device.c_str());
      return false;
    }

    if (!GetCommState(hCom, &dcb))
    {
      err("ERROR: Can't get CommState.\n");
      Close();
      return false;
    }

    switch (baud)
    {
      case 9600:
        dcb.BaudRate = CBR_9600;
        break;

      case 19200:
        dcb.BaudRate = CBR_19200;
        break;

      case 110:
        dcb.BaudRate = CBR_110;
        break;

      case 300:
        dcb.BaudRate = CBR_300;
        break;

      case 38400:
        dcb.BaudRate = CBR_38400;
        break;

      case 600:
        dcb.BaudRate = CBR_600;
        break;

      case 56000:
        dcb.BaudRate = CBR_56000;
        break;

      case 1200:
        dcb.BaudRate = CBR_1200;
        break;

      case 57600:
        dcb.BaudRate = CBR_57600;
        break;

      case 2400:
        dcb.BaudRate = CBR_2400;
        break;

      case 115200:
        dcb.BaudRate = CBR_115200;
        break;

      case 4800:
        dcb.BaudRate = CBR_4800;
        break;

      case 128000:
        dcb.BaudRate = CBR_128000;
        break;

      case 256000:
        dcb.BaudRate = CBR_256000;
        break;

      case 14400:
        dcb.BaudRate = CBR_14400;
        break;

      default:
        fprintf(stderr, "ERROR: Baut rate currently not supported.\n");
        Close();
        return false;
    }

    dcb.ByteSize = 8;
    dcb.fParity = FALSE;
    dcb.fDsrSensitivity = FALSE;
    dcb.fDtrControl = DTR_CONTROL_DISABLE;
    dcb.fOutxCtsFlow = FALSE;
    dcb.fOutxDsrFlow = FALSE;
    dcb.fOutX = FALSE;
    dcb.fInX = FALSE;
    dcb.fRtsControl = RTS_CONTROL_DISABLE;
    dcb.Parity = NOPARITY;
    dcb.StopBits = ONESTOPBIT;

    if(!SetCommState(hCom, &dcb))
    {
      fprintf(stderr, "ERROR: Can't set CommState.\n");
      Close();
      return false;
    }

    return true;
#else
    struct termios tio;
    speed_t bf;
    int baud_in, baud_out;

    // open device
    fd = ::open(device.c_str(), O_RDWR | O_SYNC);
    perror("><");
    qDebug() << "fd = " << fd;
    if (fd < 0)
      return(false);

    /* set control attributes -
     * binary I/O, no flow control
     */
    tcgetattr(fd, &tio);
    cfmakeraw(&tio);
    tio.c_cflag &= ~(CRTSCTS | IXON | IXOFF);

    // set serial port speed
    bf = baud_rate_to_flag(baud);
    cfsetispeed(&tio, bf);
    cfsetospeed(&tio, bf);
    tcsetattr(fd, TCSANOW, &tio);

    // test what actually got set
    memset(&tio, 0, sizeof(tio));
    tcgetattr(fd, &tio);
    baud_in  = baud_flag_to_rate(cfgetispeed(&tio));
    baud_out = baud_flag_to_rate(cfgetospeed(&tio));

    return((baud_in == baud) && (baud_out == baud));
#endif
  }


  /*
   * close -
   *
   * this function closes the serial port module
   */
  void Serial::Close(void)
  {
#ifdef WIN32

    if(!CloseHandle(hCom))
      fprintf(stderr, "ERROR: Can't close comm port.\n");

    hCom = INVALID_HANDLE_VALUE;
#else

    if(fd)
    {
      ::close(fd);
      fd = 0;
    }

#endif
  }

  /*
   * Read -
   *
   * function reads bytes from the serial port
   */
#ifdef WIN32
  int Serial::Read(void *buf, int size)
  {
    DWORD bytesTransfered;

    if(!ReadFile(hCom, (char*)buf, size, &bytesTransfered, NULL))
    {
      err("ERROR: Can't read from comm port.");
    }

    return bytesTransfered;
  }
#endif

  /*
   * Write -
   *
   * Function writes bytes to the serial port
   */
#ifdef WIN32
  int Serial::Write(void *buf, int size)
  {
    DWORD bytesTransfered;

    if(!WriteFile(hCom, (char*)buf, size, &bytesTransfered, NULL ))
    {
      err(stderr, "Can't write to comm port.");
    }

    return bytesTransfered;
  }
#endif

  /*
   * Writebyte -
   *
   * Function writes a signel byte to the serial port
   */
  int Serial::WriteByte(char b)
  {
#ifdef WIN32
    return Write(&b, 1);
#else
    return (::write(fd, &b, 1));
#endif
  }


  /*
   * ReadByte -
   *
   * function reads a single byte from the serial port
   */
  int Serial::ReadByte(void)
  {
#ifdef WIN32
    char b;
    return Read(&b, 1);
    return b;
#else
    char  data;
    int   ret_val;

    if ((ret_val = ::read(fd, &data, 1)) < 0)
      return (ret_val);

    return (data);
#endif
  }
   /*
   * ReadByteTimeout -
   *
   * function reads a single byte from the serial port, timing out after given ms if no byte is found.
   * NOTE: does not work on WIN32, simply becomes ReadByte
   */
  int Serial::ReadByteTimeout(float ms, bool &ok)
  {
    ok = false;
#ifdef WIN32
    char b;
    return Read(&b, 1);
    return b;
#else
    int ret_val;
    char data;
    FD_ZERO(&set); /* clear the set */
    FD_SET(fd, &set); /* add our file descriptor to the set */
    timeout.tv_sec = 0;
    timeout.tv_usec = ms*1000;

    int rv = select(fd + 1, &set, NULL, NULL, &timeout);
    if(rv == -1)
      perror("select"); /* an error accured */
    else if(rv == 0){}
      //printf("><><><><><><>::::::::::><><><><><><><>timeout\n"); /* a timeout occured */
    else {
      ok = true;
      if ((ret_val = ::read(fd, &data, 1)) < 0)
        return (ret_val);
      return (data);
    }
    return data;
#endif
  }
  int Serial::ReadNBytesTimeout(int n, char *data, float ms, bool &ok)
  {
    ok = false;
#ifdef WIN32
    char b;
    return Read(&b, 1);
    return b;
#else
    int ret_val;
    FD_ZERO(&set); /* clear the set */
    FD_SET(fd, &set); /* add our file descriptor to the set */
    timeout.tv_sec = 0;
    timeout.tv_usec = ms*1000;

    int rv = select(fd + 1, &set, NULL, NULL, &timeout);
    if(rv == -1)
      perror("select"); /* an error accured */
    else if(rv == 0){}
//      printf("><><><><><><>::::::::::><><><><><><><>timeout\n"); /* a timeout occured */
    else {
      ok = true;
      ret_val = ::read(fd, data, n);
      return (ret_val);
    }
    return -1;
#endif
  }
  void Serial::Clear()
  {
    #if WIN32
    #else
    tcflush(fd,TCIOFLUSH);
    #endif
  }
} // namespace HAL