Hi everybody!
I am trying to communicate with the SSC-32 under Linux (Ubuntu 10.04) and C++. I am having a hard time with it, and I would deeply appreciate if anyone could give me any hint.
The thing is, if I use minicom with the following configuration I can send commands to the SSC 32 without problems (for example: #4P1000 would move the servo on channel 4 to position 1000 perfectly):
Serial Device: /dev/ttyS0
Bps/Par/Bits : 115200 8N1
Hardware Flow Control : No
Software Flow Control : No
But when I use my own program, it doesn’t work. Here is the source code:
[code]SerialPort.h:
#ifndef SerialPort_h
#define SerialPort_h
#include
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
#include
#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
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;
}
}[/code]
When I execute the main program, I get no errors:
$ ./main
Created an object of type SerialPort
Opening: /dev/ttyS0
The serial port is open.
#0P1000
Wrote bytes: 8
The servo should move now
File descriptor: 3
Serial port successfully closed.
But it looks like the command doesn’t reach the SSC-32 (the green led is always ON). I guess it must be an error in my configuration flags or something like that. Any ideas? I really don’t know what else to do, I’ve surfed the web, ripped out the source code of minicom but yet… no results. You are my last hope 
Thank you very much in advance.
Cosmo.
Fortunately I already solved the issue some time ago.