libdxl::dxlhal Class Reference

Public Member Functions
	dxlhal ()
	Default constructor.
	~dxlhal ()
	Destructor.
int	open (const char *deviceName, int baudrate)
	Open Dynamixel Bus USB serial device by name. More...
int	dxl_hal_open (int deviceIndex, float baudrate)
	Open Dynamixel Bus USB serial device by index. More...
void	close ()
	Close Dynamixel Bus serial interface.
std::string	getDeviceName ()
	Get the Dynamixel Bus serial device name. More...
int	getBaudRate ()
	Get the Dynamixel Bus serial device baud rate. More...
int	getFd ()
	Get the Dynamixel Bus serial device file descriptor. More...
int	setBaudRate (int baudrate)
	Set opened Dynamixel Bus serial interface baud rate. More...
void	clear ()
	Discard any pending recieve data.
int	tx (unsigned char *pPacket, int numPacket)
	Transmit Dynamixel instruction packet. More...
int	rx (unsigned char *pPacket, int numPacket)
	Receive Dynamixel status packet. More...
void	setTimeout (int NumRcvByte)
	Set receive timeout. More...
bool	hasTimedOut ()
	Test if receive timeout has expired. More...

Protected Member Functions
double	calcSecPerByte (int baudrate)
	Calculate seconds/byte transmit/recieve time in seconds. More...
double	now ()
	Mark time. More...

Protected Attributes
std::string	m_strDeviceName
	device name
int	m_nBaudRate
	device baud rate
int	m_fd
	device file descriptor
double	m_fSecPerByte
	seconds per byte transfer time
double	m_fStartTime
	event start time
double	m_fRcvWaitTime
	receive max elapse wait time

Detailed Description

Definition at line 39 of file dxlhal.h.

Member Function Documentation

double dxlhal::calcSecPerByte ( int  baudrate )

protected

Calculate seconds/byte transmit/recieve time in seconds.

Note

Over serial, START_BIT byte STOP_BIT = 10 bits.

Parameters

baudrate

Serial baud rate.

Returns

Seconds per byte.

Definition at line 289 of file dxlhal.cxx.

{
  if( baudrate > 0 )
  {
    return 10.0/(double)baudrate;
  }
  else
  {
    return 0.0;
  }
}

int dxlhal::dxl_hal_open	(	int	deviceIndex,
		float	baudrate
	)

Open Dynamixel Bus USB serial device by index.

The serial device is opened and attributes set.

Note

This method is deprecated. The preferred method is open().

Parameters

deviceIndex	Device number of /dev/ttyUSBn, n == deviceIndex.
baudrate	Serial baud rate.

Returns

Returns 1 on success, 0 on failure.

Definition at line 86 of file dxlhal.cxx.

Referenced by libdxl::dxl::dxl_initialize().

{
  char buf[256];
  struct termios newtio;
  struct serial_struct serinfo;

  close();

  snprintf(buf, sizeof(buf), "/dev/ttyUSB%d", deviceIndex);

  buf[sizeof(buf)-1] = 0;

  m_strDeviceName = buf;
  m_nBaudRate     = baudrate;

  memset(&newtio, 0, sizeof(newtio));
  
  if( (m_fd = open(m_strDeviceName.c_str(), O_RDWR|O_NOCTTY|O_NONBLOCK)) < 0 )
  {
    LOGSYSERROR("%s: Device open error.", m_strDeviceName.c_str());
    goto DXL_HAL_OPEN_ERROR;
  }

  newtio.c_cflag    = B38400|CS8|CLOCAL|CREAD;
  newtio.c_iflag    = IGNPAR;
  newtio.c_oflag    = 0;
  newtio.c_lflag    = 0;
  newtio.c_cc[VTIME]  = 0;  // time-out 값 (TIME * 0.1초) 0 : disable
  newtio.c_cc[VMIN]  = 0;  // MIN 은 read 가 return 되기 위한 최소 문자 개수

  tcflush(m_fd, TCIFLUSH);
  tcsetattr(m_fd, TCSANOW, &newtio);
  
  if(ioctl(m_fd, TIOCGSERIAL, &serinfo) < 0)
  {
    LOGSYSERROR("%s(fd=%d): Cannot get serial info.",
        m_strDeviceName.c_str(), m_fd);
    return 0;
  }
  
  serinfo.flags &= (int)(~ASYNC_SPD_MASK);
  serinfo.flags |= (int)ASYNC_SPD_CUST;
  serinfo.custom_divisor = (int)((float)serinfo.baud_base / baudrate);
  
  if(ioctl(m_fd, TIOCSSERIAL, &serinfo) < 0)
  {
    LOGSYSERROR("%s(fd=%d): Cannot set serial info.",
        m_strDeviceName.c_str(), m_fd);
    goto DXL_HAL_OPEN_ERROR;
  }
  
  m_fSecPerByte = calcSecPerByte(baudrate);
  
  return 1;

DXL_HAL_OPEN_ERROR:
  close();
  return 0;
}

int dxlhal::getBaudRate

(

)

Get the Dynamixel Bus serial device baud rate.

Returns

Returns baud rate.

Definition at line 163 of file dxlhal.cxx.

{
  return m_nBaudRate;
}

string dxlhal::getDeviceName

(

)

Get the Dynamixel Bus serial device name.

Returns

String.

Definition at line 158 of file dxlhal.cxx.

{
  return m_strDeviceName;
}

int dxlhal::getFd

(

)

Get the Dynamixel Bus serial device file descriptor.

Returns

Returns >= 0 if the device is open, -1 otherwise.

Definition at line 168 of file dxlhal.cxx.

Referenced by libdxl::dxl::getFd().

{
  return m_fd;
}

bool dxlhal::hasTimedOut

(

)

Test if receive timeout has expired.

Returns

Returns 1 if true, false otherwise.

Definition at line 260 of file dxlhal.cxx.

Referenced by libdxl::dxl::rxPacket().

{
  double  t1, t;
  
  t1  = now();
  t   = t1 - m_fStartTime;
  
  //fprintf(stderr, "DBG: st=%lf, now=%lf, elapse=%lf\n", m_fStartTime, t1, t);

  if( t > m_fRcvWaitTime )
  {
    return true;
  }

  else
  {
    return false;
  }
}

double dxlhal::now ( )

protected

Mark time.

Returns

Return marked time in seconds.

Definition at line 280 of file dxlhal.cxx.

{
  struct timespec ts;

  clock_gettime(CLOCK_REALTIME, &ts);
  
  return (double)ts.tv_sec + (double)ts.tv_nsec / 1000000000.0;
}

int dxlhal::open	(	const char *	deviceName,
		int	baudrate
	)

Open Dynamixel Bus USB serial device by name.

The serial device is opened and attributes set.

Parameters

deviceName	Name of serial device.
baudrate	Serial baud rate.

Returns

Returns 1 on success, 0 on failure.

Definition at line 60 of file dxlhal.cxx.

Referenced by libdxl::dxl::open().

{
  close();

  m_strDeviceName = deviceName;
  m_nBaudRate     = baudrate;

  m_fd = SerDevOpen(m_strDeviceName.c_str(), baudrate, 8, 'N', 1, false, false);

  if( m_fd >= 0 )
  {
    m_fSecPerByte = calcSecPerByte(baudrate);
  
    return 1;
  }
  else
  {
    LOGSYSERROR("%s: Failed to open.", m_strDeviceName.c_str());
  
    m_strDeviceName.clear();
    m_nBaudRate      = 0;

    return 0;
  }
}

int dxlhal::rx	(	unsigned char *	pPacket,
		int	numPacket
	)

Receive Dynamixel status packet.

Parameters

[out]	pPacket	Packed packet.
	numPacket	Number of bytes to read.

Returns

On success, number of bytes received. -1 on error.

Definition at line 229 of file dxlhal.cxx.

Referenced by libdxl::dxl::rxPacket().

{
  static unsigned int Slop = 1000;    // 1 millisecond slop

  unsigned int  usec;
  ssize_t       n;

  memset(pPacket, 0, (size_t)numPacket);

  usec = (unsigned int)((double)numPacket * m_fSecPerByte * 1000000.0) + Slop;

  //fprintf(stderr, "DBG: rx wait time for %d bytes is %uus.\n",
  //    numPacket, usec);

  n = SerDevRead(m_fd, pPacket, (size_t)numPacket, usec);

  return n < 0? 0: (int)n;
}

int dxlhal::setBaudRate

(

int

baudrate

)

Set opened Dynamixel Bus serial interface baud rate.

Parameters

baudrate

Baud rate.

Returns

Returns 1 on success, 0 on failure.

Definition at line 173 of file dxlhal.cxx.

Referenced by libdxl::dxl::setBaudRate().

{
  struct serial_struct serinfo;
  
  if( m_fd == -1 )
  {
    return 0;
  }
  
  if(ioctl(m_fd, TIOCGSERIAL, &serinfo) < 0)
  {
    LOGERROR("%s(fd=%d): Cannot get serial info.",
        m_strDeviceName.c_str(), m_fd);
    return 0;
  }
  
  serinfo.flags &= (int)(~ASYNC_SPD_MASK);
  serinfo.flags |= (int)ASYNC_SPD_CUST;
  serinfo.custom_divisor = (int)((float)serinfo.baud_base / (float)baudrate);
  
  if(ioctl(m_fd, TIOCSSERIAL, &serinfo) < 0)
  {
    LOGERROR("%s(fd=%d): Cannot set serial info.",
        m_strDeviceName.c_str(), m_fd);
    return 0;
  }
  
  m_fSecPerByte = calcSecPerByte(baudrate);

  m_nBaudRate = baudrate;

  return 1;
}

void dxlhal::setTimeout

(

int

NumRcvByte

)

Set receive timeout.

Parameters

NumRcvByte

Number of expected receive bytes

Definition at line 248 of file dxlhal.cxx.

References MAX_T_RTD.

Referenced by libdxl::dxl::txPacket().

{
  static double  Fudge = 0.010;    // yea ol fudge factor

  m_fStartTime = now();

  m_fRcvWaitTime = m_fSecPerByte * (double)NumRcvByte + MAX_T_RTD + Fudge;

  //fprintf(stderr, "DBG: to wait time = %lfs from now = %lfs.\n",
  //    m_fRcvWaitTime, m_fStartTime);
}

int dxlhal::tx	(	unsigned char *	pPacket,
		int	numPacket
	)

Transmit Dynamixel instruction packet.

Parameters

[in]	pPacket	Packed packet.
	numPacket	Number of bytes to transmit.

Returns

Returns 1 on success, 0 on failure.

Definition at line 212 of file dxlhal.cxx.

Referenced by libdxl::dxl::txPacket().

{
  ssize_t       n;

  n = SerDevWrite(m_fd, pPacket, (size_t)numPacket, 0);

  if( n > 0 )
  {
    return (int)n;
  }
  else
  {
    LOGERROR("tx failed.");
    return 0;
  }
}

---

The documentation for this class was generated from the following files:

• libdxl/dxlhal.h
• libdxl/dxlhal.cxx