Creating a Serial to USB Driver

Hi,

I am a totally newbie in windows driver development. I currently
required to develop a serial to USB driver for a USB device such that
the driver will appear to be a normal COM port under Windows but
underneath data are transfered to the USB port. I really need some
sort of guide or example codes to do this. I found the guide by Eliyas
Yakub in here but i totally don't understand the guide. Please help.

Bill
Wed Jul 21 23:00:16 CDT 2004

I hope you have been given a LOT of time to get this done. If you cannot
understand what Eliyas wrote, you are in for a steep learning curve. Your
best bet is to study the serial sample in the DDK and try to understand it.
Unfortunately, that driver is extremely complex and a good bit obfuscated
with all of the multi-port code and such. Beyond that, a good WDM book such
as that written by Walter Oney is a must. You have been tasked with an
advanced project, I hope your superiors understand this.

--
Bill McKenzie
Software Engineer - Prism 802.11 Wireless Solutions
Conexant Systems, Inc.

"Daryl Ng" <tigger4@pacific.net.sg> wrote in message
news:a31de658.0407211941.35635237@posting.google.com...
> Hi,
>
> I am a totally newbie in windows driver development. I currently
> required to develop a serial to USB driver for a USB device such that
> the driver will appear to be a normal COM port under Windows but
> underneath data are transfered to the USB port. I really need some
> sort of guide or example codes to do this. I found the guide by Eliyas
> Yakub in here but i totally don't understand the guide. Please help.

Robert
Thu Jul 22 07:42:36 CDT 2004

Bill McKenzie wrote:

> Beyond that, a good WDM book such as that written by Walter Oney is a must.

Walter Oney is the author of several instances of this driver.
He is definitely the main authority on this driver.

(Walter, your job to sell another one ;)

Walter
Thu Jul 22 09:08:24 CDT 2004

Robert Marquardt wrote:
> Bill McKenzie wrote:
> > Beyond that, a good WDM book such as that written by Walter Oney is a must.
> Walter Oney is the author of several instances of this driver.
> He is definitely the main authority on this driver.
> (Walter, your job to sell another one ;)

Thanks for the vote of confidence. I usually advise people that this
kind of driver is difficulty 5 on a scale of 1-5. Every commercial
USB-serial driver I've seen has major flaws in the way it handles the
signal lines, for example. It's a wonder they're able to get faxing to
work.

I also try to talk people out of doing this project because MOST people
just need a modem, and USBSER suffices for that.

--
Walter Oney, Consulting and Training
Basic and Advanced Driver Programming Seminars
Check out our schedule at http://www.oneysoft.com

Daryl
Fri Jul 23 00:42:03 CDT 2004

Frstly thanks for the replies

Currently the USB device i working on uses the Cypress EZ-USB Microcontroller. I have a working driver from Cypress for direct accessing the chip through USB port already. The Serial-to-USB driver is just for directing data from USB to serial and vice versa. Serial port feature like setting of baud rate etc is currently not needed.

Walter, you mention that the modem and USBSER is suffice. Do you mean the usbser.sys driver? How does I go about that? Thanks

"Walter Oney" wrote:

> Thanks for the vote of confidence. I usually advise people that this
> kind of driver is difficulty 5 on a scale of 1-5. Every commercial
> USB-serial driver I've seen has major flaws in the way it handles the
> signal lines, for example. It's a wonder they're able to get faxing to
> work.
>
> I also try to talk people out of doing this project because MOST people
> just need a modem, and USBSER suffices for that.
>
> --
> Walter Oney, Consulting and Training
> Basic and Advanced Driver Programming Seminars
> Check out our schedule at http://www.oneysoft.com
>

Daryl
Fri Jul 23 00:49:02 CDT 2004

First of all, thanks for the replies.

The USB device I am developing the driver for is a Cypress EZ-USB Microcontroller. I already have a USB driver for accessing the microcontroller directly from Cypress. The USB device is used to replace our customer old device which uses a serial interface. Hence, we need to develop a Serial-to-USB driver as the customer did not wish to change their applications. This Serial-to-USB driver only passes data along.

Walter, you mention using the modem and USBSER. Is tis the usbser.sys? Can you advice how am I going do it? Thanks


"Walter Oney" wrote:

> Robert Marquardt wrote:
> > Bill McKenzie wrote:
> > > Beyond that, a good WDM book such as that written by Walter Oney is a must.
> > Walter Oney is the author of several instances of this driver.
> > He is definitely the main authority on this driver.
> > (Walter, your job to sell another one ;)
>
> Thanks for the vote of confidence. I usually advise people that this
> kind of driver is difficulty 5 on a scale of 1-5. Every commercial
> USB-serial driver I've seen has major flaws in the way it handles the
> signal lines, for example. It's a wonder they're able to get faxing to
> work.
>
> I also try to talk people out of doing this project because MOST people
> just need a modem, and USBSER suffices for that.
>
> --
> Walter Oney, Consulting and Training
> Basic and Advanced Driver Programming Seminars
> Check out our schedule at http://www.oneysoft.com
>

Walter
Fri Jul 23 06:36:05 CDT 2004

Daryl Ng wrote:
> Walter, you mention that the modem and USBSER is suffice. Do you mean the usbser.sys driver? How does I go about that?

Just make your device conform to the CDC spec.

--
Walter Oney, Consulting and Training
Basic and Advanced Driver Programming Seminars
Check out our schedule at http://www.oneysoft.com