USB and software, question

Hello! I have experience in writing own .exe programs for Windows, but i have no idea how to get information from Arduino board via USB. Main idea is that i want to read data from serial port right in my program instead of using Arduino IDE. Could you please tell me what exactly stuff i should use or what code i should write so my .exe application can talk with Arduino board via USB?

What language on Windows? In general, you can open "COM3:" or similar and read it just like any other file (the Arduino ends up emulating a serial port.) For some purposes, you may need a serial port library (to change speed/etc.)

westfw: What language on Windows? In general, you can open "COM3:" or similar and read it just like any other file (the Arduino ends up emulating a serial port.) For some purposes, you may need a serial port library (to change speed/etc.)

I program on C language. Yes i heard that COM port can be opened just like file, but how? Via fopen() function? What then i should write instead of file name? When i was trying to find something in Google, it was giving me usually complicated examples, nothing with simple fopen =\

This Simple Python - Arduino demo should give you the general idea about the PC-Arduino communication. You should be able to replace the Python code with equivalent functionality in any other programming language.

I believe the Python example works with Windows if you edit it to use the appropriate COM port reference.

...R