Hi,
These all have separate answers. And, if you are interested in C/C++, you
posted in the wrong newsgroup (this is a Visual Studio .NET newsgroup).
Serial communications uses either a serial comms add-on (there are lots of
these around, many of them free). For example, downloads from my homepage,
and code in my book (below)
Parallel comms requires a device driver. I have a .NET control that wraps
such a driver on my homepage (see IONet).
Here is my USB FAQ:
You normally use whatever API is required for the specific hardware device
that is attached to the USB port. There is no general-purpose driver for
this. So, if you are connecting to a serial device, you use the Windows
serial APIs. If a sound device, you use the MCI APIs. If a disk drive, you
use the various file APIs. The actual driver that is installed when Windows
detects the USB device translates these Windows APIs to the device specific
commands required for the actual hardware.
However, if you have custom built USB hardware, you need lower level access
to the device. You must know A LOT about the hardware before this sort of
thing is useful. I suggest that you get a copy of Jan Axelson's book, USB
Complete, 2nd Edition. You can get information on it from the Books link on
my homepage.
If you just want to use a USB serial port adapter to connect to an RS-232
device, then you may use MSComm or any of the other serial communications
methods that are described in detail in my book.
--
Richard Grier (Microsoft Visual Basic MVP)
See
www.hardandsoftware.net for contact information.
Author of Visual Basic Programmer's Guide to Serial Communications, 4th
Edition ISBN 1-890422-28-2 (391 pages) published July 2004. See
www.mabry.com/vbpgser4 to order.
