Read data from a serial port to USB in Ubuntu using C++

Question

I have a GPS that has a serial port, and it has a transfer cable from serial to USB. It is connected to the laptop through USB, and is transmitting data in Hex. I want to use this data in my C++ code on Ubuntu. Any ideas where could I start, and how I could manage to read the data?

Answer 1

Start by opening a file (fstream, FILE * or OS handle) to "/dev/ttySn" where n is the number of the device, then read away.

#include <string>
#include <fstream>
#include <iostream>

std::string str; 
std::fstream f; 
f.open("/dev/ttyS0"); 
while (f >> str)
{
   std::cout << str;
}

That should "echo" out the contents of ttyS0 - that may of course be the "wrong" port for your device, but if you know where it is connected that should do the job. You may also need to set the configuration of the port. For example, using the stty command - baudrate would be the most important, so something like stty -F /dev/ttyS0 19200 will set the baudrate (actually bitrate) to 19200 bits per second. Most other parameters are probably ok.