Lynxmotion Tech Support

SerialPort.h:
-----------------
#ifndef _SerialPort_h_
#define _SerialPort_h_

#include <string>
class SerialPort
{

private:
   std::string mSerialPortName ;

   int mFileDescriptor ;
   

public:
   
   enum BufferSize {
      BUFFER_SIZE = 64
   } ;
   
   SerialPort ( ) ;
   
   bool Open( const std::string& mSerialPortName ) ;
   
   bool Close (  ) ;
   
   bool Write ( const char *writeBuffer, int bufferSize ) ;
   
   int Read ( unsigned char *readBuffer ) ;
} ;

#endif

SerialPort.cpp:
----------------------
#include <iostream>
#include <string>
#include <fcntl.h>
#include <unistd.h>
#include <termios.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>

#include "SerialPort.h"


SerialPort::SerialPort ( )
{
   mFileDescriptor = -1;
}

bool SerialPort::Open( const std::string& mSerialPortName )
{
   struct termios ios;
   
   if (mFileDescriptor != -1)
   {
      std::cerr << "WARNING: There is one serial port already open. Close it first." << std::endl;
   }
   
   this->mSerialPortName = mSerialPortName;
   std::cout << "Opening: " << this->mSerialPortName << std::endl;
   
   if ((mFileDescriptor = open (this->mSerialPortName.c_str(), O_RDWR | O_NOCTTY )) < 0)
   {
      std::cerr << "ERROR: Could not open " << this->mSerialPortName << std::endl;
      return false;
   }
   
   if (!isatty(mFileDescriptor))
   {
      std::cerr << "ERROR: "<< this->mSerialPortName << " is not a tty." << std::endl;
      Close();
      return false;
   }
   
   if ( tcgetattr(mFileDescriptor, &ios) != 0 )
   {
      std::cerr << "ERROR: Could not get serial port parameters"<< std::endl;
   }
   
   //Set communication speed
   cfsetispeed(&ios, B115200);
   cfsetospeed(&ios, B115200);
   
   //Set 8 data bits
   ios.c_cflag = (ios.c_cflag & ~CSIZE) | CS8;
   
   //Set into raw, no echo mode
   ios.c_iflag = IGNBRK;
   ios.c_lflag = 0;
   ios.c_oflag = 0;
   ios.c_cflag |= CLOCAL | CREAD;
   
   
   //Disable software flow control
   ios.c_iflag &= ~(IXON|IXOFF|IXANY);
   
   //Disable hardware flow control
   ios.c_cflag &= ~CRTSCTS;
   
   //Disable parity
   ios.c_cflag &= ~(PARENB | PARODD);
   
   //One stop bit
   ios.c_cflag &= ~CSTOPB;
   
   
   if (tcsetattr(mFileDescriptor, TCSANOW, &ios) == -1)
   {
      std::cerr << "ERROR: Problem with tcsetattr" << std::endl;
      return false;
   }
   
   
   return true;
}

bool SerialPort::Close ( )
{
   std::cerr<< "File descriptor: " << mFileDescriptor << std::endl;

   if (mFileDescriptor == -1)
   {
      std::cerr << "WARNING: The serial port is not open." << std::endl;
      return false;
   }
   
   if (close(mFileDescriptor)==0)
   {
      mFileDescriptor = -1;
      return true;
   }
   else
   {
      perror("ERROR: ");
      std::cerr << "ERROR: Problem closing serial port." << std::endl;
      mFileDescriptor = -1;
      return false;
   }
}

bool SerialPort::Write ( const char *writeBuffer, int bufferSize )
{
   int s;
   
   if (mFileDescriptor == -1)
   {
      std::cerr << "ERROR: Serial port not open." << std::endl;
      return false;
   }
   
   s = write(mFileDescriptor, writeBuffer, bufferSize );
   
   if (tcflush(mFileDescriptor, TCIOFLUSH) == -1)
      std::cerr << "WARNING: Could not flush serial port" << std::endl;
   
   if (s!=bufferSize)
   {
      std::cerr << "ERROR: Could not write to serial port" << std::endl;
      return false;
   }
   std::cerr << writeBuffer << std::endl;
   std::cerr << "Wrote bytes: " << s << std::endl;

   return true;
}

main.c:
-----------
#include "SerialPort.h"
#include <iostream>

int main( int argc, const char **argv)
{

   unsigned char buff[SerialPort::BUFFER_SIZE];
   SerialPort mySerial;
   std::cout << "Created an object of type SerialPort" << std::endl;


   if (mySerial.Open("/dev/ttyS0"))
   {
      std::cout << "The serial port is open." << std::endl;
   }


   if (mySerial.Write("#0P1000\r",8))
   {
      std::cout << "The servo should move now" << std::endl;
   }
   else
   {
      std::cout << "Oh crap..." << std::endl;
   }   


   sleep(2);

   if (mySerial.Close( ))
   {
      std::cout << "Serial port successfully closed." << std::endl;
   }
}