serialcomm_s300.cpp

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/*
 *
 * serialcomm_s300.cpp
 *
 *
 * Copyright (C) 2010
 * Autonomous Intelligent Systems Group
 * University of Bonn, Germany
 *
 *
 * Authors: Andreas Hochrath, Torsten Fiolka
 *
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 *
 * Origin:
 *  Player - One Hell of a Robot Server
 *  serialstream.cc & sicks3000.cc
 *  Copyright (C) 2003
 *     Brian Gerkey
 *  Copyright (C) 2000
 *     Brian Gerkey, Kasper Stoy, Richard Vaughan, & Andrew Howard
 *
 */

#include "serialcomm_s300.h"

#include <assert.h>
#include <math.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <sys/stat.h>

#include <termios.h>
#include <unistd.h>
#include <sys/ioctl.h>

#include <iostream>

SerialCommS300::SerialCommS300()
{
  m_rxCount = 0;
  m_ranges = NULL;
}

SerialCommS300::~SerialCommS300()
{
  disconnect();
}

int SerialCommS300::connect(const std::string& deviceName, unsigned int baudRate)
{

  m_fd = ::open(deviceName.c_str(), O_RDWR | O_NOCTTY | O_NDELAY | O_NONBLOCK);
  if (m_fd < 0)
  {
    std::cout << "SerialCommS300: unable to open serial port " << deviceName << "\n";
    return -1;
  }

  setFlags();
  if (setBaudRate(baudRateToBaudCode(baudRate)))
    return -1;

  tcflush(m_fd, TCIOFLUSH);
  usleep(1000);
  tcflush(m_fd, TCIFLUSH);

  return 0;

}

void SerialCommS300::setFlags()
{

  // set up new settings
  struct termios term;
  memset(&term, 0, sizeof(term));

  tcgetattr(m_fd, &term);

  term.c_cc[VMIN] = 0;
  term.c_cc[VTIME] = 0;
  term.c_cflag = CS8 | CREAD;
  term.c_iflag = INPCK;
  term.c_oflag = 0;
  term.c_lflag = 0;

  if (tcsetattr(m_fd, TCSANOW, &term) < 0)
    std::cout << "SerialCommS300: failed to set tty device attributes";
  tcflush(m_fd, TCIOFLUSH);

}

int SerialCommS300::setBaudRate(int baudRate)
{

  struct termios term;

  if (tcgetattr(m_fd, &term) < 0)
  {
    std::cout << "SerialCommS300: unable to get device attributes\n";
    return 1;
  }

  if (cfsetispeed(&term, baudRate) < 0 || cfsetospeed(&term, baudRate) < 0)
  {
    std::cout << "SerialCommS300: failed to set serial baud rate " << baudRate << "\n";
    return 1;
  }

  if (tcsetattr(m_fd, TCSAFLUSH, &term) < 0)
  {
    std::cout << "SerialCommS300: unable to set device attributes\n";
    return 1;
  }

  return 0;
}

int SerialCommS300::baudRateToBaudCode(int baudRate)
{
  switch (baudRate)
  {
    case 38400:
      return B38400;
    case 115200:
      return B115200;
    case 500000:
      return B500000;
    default:
      return B500000;
  };
}

int SerialCommS300::disconnect()
{
  ::close(m_fd);
  return 0;
}

static const unsigned short crc_table[256] = {0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7, 0x8108,
                                              0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef, 0x1231, 0x0210,
                                              0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6, 0x9339, 0x8318, 0xb37b,
                                              0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de, 0x2462, 0x3443, 0x0420, 0x1401,
                                              0x64e6, 0x74c7, 0x44a4, 0x5485, 0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee,
                                              0xf5cf, 0xc5ac, 0xd58d, 0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6,
                                              0x5695, 0x46b4, 0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d,
                                              0xc7bc, 0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
                                              0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b, 0x5af5,
                                              0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12, 0xdbfd, 0xcbdc,
                                              0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a, 0x6ca6, 0x7c87, 0x4ce4,
                                              0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41, 0xedae, 0xfd8f, 0xcdec, 0xddcd,
                                              0xad2a, 0xbd0b, 0x8d68, 0x9d49, 0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13,
                                              0x2e32, 0x1e51, 0x0e70, 0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a,
                                              0x9f59, 0x8f78, 0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e,
                                              0xe16f, 0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
                                              0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e, 0x02b1,
                                              0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256, 0xb5ea, 0xa5cb,
                                              0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d, 0x34e2, 0x24c3, 0x14a0,
                                              0x0481, 0x7466, 0x6447, 0x5424, 0x4405, 0xa7db, 0xb7fa, 0x8799, 0x97b8,
                                              0xe75f, 0xf77e, 0xc71d, 0xd73c, 0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657,
                                              0x7676, 0x4615, 0x5634, 0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9,
                                              0xb98a, 0xa9ab, 0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882,
                                              0x28a3, 0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
                                              0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92, 0xfd2e,
                                              0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9, 0x7c26, 0x6c07,
                                              0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1, 0xef1f, 0xff3e, 0xcf5d,
                                              0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8, 0x6e17, 0x7e36, 0x4e55, 0x5e74,
                                              0x2e93, 0x3eb2, 0x0ed1, 0x1ef0};

unsigned short SerialCommS300::createCRC(unsigned char* data, ssize_t length)
{

  unsigned short CRC_16 = 0xFFFF;
  unsigned short i;

  for (i = 0; i < length; i++)
  {
    CRC_16 = (CRC_16 << 8) ^ (crc_table[(CRC_16 >> 8) ^ (data[i])]);
  }

  return CRC_16;

}

int SerialCommS300::readData()
{

  if (RX_BUFFER_SIZE - m_rxCount > 0)
  {

    // Read a packet from the laser
    int len = read(m_fd, &m_rxBuffer[m_rxCount], RX_BUFFER_SIZE - m_rxCount);
    if (len == 0)
    {
      return -1;
    }

    if (len < 0)
    {
      std::cout << "SerialCommS300: error reading form serial port: " << strerror(errno) << "\n";
      return -1;
    }

    m_rxCount += len;

  }

  while (m_rxCount >= 22)
  {

    // find our continuous data header
    int ii;
    bool found = false;
    for (ii = 0; ii < m_rxCount - 22; ++ii)
    {
      if (memcmp(&m_rxBuffer[ii], "\0\0\0\0\0\0", 6) == 0)
      {
        memmove(m_rxBuffer, &m_rxBuffer[ii], m_rxCount - ii);
        m_rxCount -= ii;
        found = true;
        break;
      }
    }

    if (!found)
    {
      memmove(m_rxBuffer, &m_rxBuffer[ii], m_rxCount - ii);
      m_rxCount -= ii;
      return -1;
    }

    // get relevant bits of the header
    // size includes all data from the data block number
    // through to the end of the packet including the checksum
    unsigned short size = 2 * htons(*reinterpret_cast<unsigned short *> (&m_rxBuffer[6]));
    //printf("size %d", size);
    if (size > RX_BUFFER_SIZE - 26)
    {
      std::cout << "SerialCommS300: Requested Size of data is larger than the buffer size\n";
      memmove(m_rxBuffer, &m_rxBuffer[1], --m_rxCount);
      return -1;
    }

    // check if we have enough data yet
    if (size > m_rxCount - 4)
      return -1;

    unsigned short packet_checksum = *reinterpret_cast<unsigned short *> (&m_rxBuffer[size + 2]);
    unsigned short calc_checksum = createCRC(&m_rxBuffer[4], size - 2);
    if (packet_checksum != calc_checksum)
    {
      std::cout << "SerialCommS300: Checksum's dont match, thats bad (data packet size " << size << ")\n";
      memmove(m_rxBuffer, &m_rxBuffer[1], --m_rxCount);
      continue;
    }
    else
    {
      uint8_t* data = &m_rxBuffer[20];
      if (data[0] != data[1])
      {
        std::cout << "SerialCommS300: Bad type header bytes dont match\n";
      }
      else
      {
        if (data[0] == 0xAA)
        {
          std::cout << "SerialCommS300: We got a I/O data packet we dont know what to do with it\n";
        }
        else if (data[0] == 0xBB)
        {

          int data_count = (size - 22) / 2;
          if (data_count < 0)
          {
            std::cout << "SerialCommS300: bad data count (" << data_count << ")\n";
            memmove(m_rxBuffer, &m_rxBuffer[size + 4], m_rxCount - (size + 4));
            m_rxCount -= (size + 4);
            continue;
          }

          if (m_ranges)
            delete[] m_ranges;

          m_ranges = new float[data_count];
          m_rangesCount = data_count;

          for (int ii = 0; ii < data_count; ++ii)
          {
            unsigned short distance_cm = (*reinterpret_cast<unsigned short *> (&data[4 + 2 * ii]));
            distance_cm &= 0x1fff; // remove status bits
            m_ranges[ii] = static_cast<double> (distance_cm) / 100.0;
          }

          memmove(m_rxBuffer, &m_rxBuffer[size + 4], m_rxCount - (size + 4));
          m_rxCount -= (size + 4);

          return 0;

        }
        else if (data[0] == 0xCC)
        {
          std::cout << "SerialCommS300: We got a reflector data packet we dont know what to do with it\n";
        }
        else
        {
          std::cout << "SerialCommS300: We got an unknown packet\n";
        }
      }
    }

    memmove(m_rxBuffer, &m_rxBuffer[size + 4], m_rxCount - (size + 4));
    m_rxCount -= (size + 4);
    continue;
  }

  return -1;

}