Re: Talking to USB

From: Don (phoney.email_at_yahoo.com)
Date: 11/29/04 

Date: Mon, 29 Nov 2004 16:19:26 GMT

Hi Roland,

I did locate the (USB) driver which TWAIN uses but unfortunately there
is no documentation about the driver.

What surprises me is that there is no universal USB driver for basic
communication. I understand that each device will have a different set
of commands, of course, but the basic process of sending and receiving
bytes has nothing to do with that.

Anyway... Thanks everyone!

Don.

On Sun, 28 Nov 2004 17:56:32 +0100, "roland"
<roland.demeester@skynet.be> wrote:

>Don
>You don't have to "talk" to the USB Bus, but to the driver. The driver is
>your interface to the bus. For you it's irrelevant whether the scanner is
>connected to the USB bus or to some wire: the driver is taking care about
>that.
>roland
>
>"Don" <phoney.email@yahoo.com> wrote in message
>news:41a9d4a7.9483976@news.individual.net...
>> Hi Roland,
>>
>> I do have the SDK but it's provided on "as is" basis. However, the SDK
>> does *not* address the actual USB communications! In other words, I
>> know all the low level commands and what to expect back.
>>
>> The missing piece is how do I send these commands down the USB pipe?
>>
>> In theory, that should be the most elementary bit but it's turning out
>> to be a veritable nightmare.
>>
>> Don.
>>
>> On Sun, 28 Nov 2004 13:05:43 +0100, "roland"
>> <roland.demeester@skynet.be> wrote:
>>
>> >Don
>> >Have you "contacted" the supplier of the driver (not the device, I found
>out
>> >that a lot of hardware vendors are not developing their own driver, but
>are
>> >buying it from a company developing drivers)? What you need (I assume,
>don't
>> >take it for granted!) is the documentation and library to help you
>> >communicating with the API's of your driver. I think the only
>standardized
>> >protocol is the lowest level communication protocol over the USB bus, but
>it
>> >doesn't go much further than that I'm afraid.
>> >Roland
>> >
>> >"Don" <phoney.email@yahoo.com> wrote in message
>> >news:41a88c32.11305000@news.individual.net...
>> >> Hi Roland,
>> >>
>> >> In my case it's a scanner but I can't use TWAIN because it's too high
>> >> level. I have a list of low level commands which I wish to send to the
>> >> scanner directly because they go beyond TWAIN capabilities.
>> >>
>> >> I'm beginning to realize that USB is not as simple as I thought but I
>> >> expected at least some common approach to the most basic level i.e.
>> >> identifying devices and then simple sending and receiving of bytes.
>> >>
>> >> Don.
>> >>
>> >> On Sat, 27 Nov 2004 13:42:20 +0100, "roland"
>> >> <roland.demeester@skynet.be> wrote:
>> >>
>> >> >Don
>> >> >I recently had to write an interface with a serial device that was
>> >connected
>> >> >through a usb-to-serial convertor. I spent some time browsing the net
>and
>> >I
>> >> >learned that there is no such thing as as a USB port and a USB
>protocol:
>> >you
>> >> >have to interface directly with the API's the USB driver for the
>device
>> >> >provides for.
>> >> >In my case the USB2COM convertor provided for a virtual serial port
>that
>> >I
>> >> >could communicate with, so it was fairly transparent. Unfortunately I
>> >cannot
>> >> >point you to any exemple that interfaces directly with the API's of a
>USB
>> >> >driver.
>> >> >Greetings, Roland
>> >> >
>> >> >"Don" <phoney.email@yahoo.com> wrote in message
>> >> >news:41a74dba.8602887@news.individual.net...
>> >> >> Environment: VB6 under W98
>> >> >>
>> >> >> I have a USB hardware device I wish to program directly. The
>original
>> >> >> software installed a low level driver and the hardware is both
>> >> >> registered and operational.
>> >> >>
>> >> >> Now then, I'd like to have access to this device directly. In other
>> >> >> words, I'd like to enumerate all devices on the USB bus, pick the
>one
>> >> >> I want, and then communicate with it (send commands, get data, etc).
>> >> >>
>> >> >> So, how does one go about talking to the USB? VB6/W98 combo doesn't
>> >> >> seem to have any dedicated USB routines.
>> >> >>
>> >> >> What I need - I guess - is the USB equivalent of the MSComm control.
>> >> >> Is there such a thing as a "USB Control"? What's the canonical way
>of
>> >> >> talking to USB from VB?
>> >> >>
>> >> >> I did google around a bit but couldn't find anything applicable.
>Most
>> >> >> sites and pages I came across seem to focus on actually writing a
>low
>> >> >> level USB driver.
>> >> >>
>> >> >> Thanks!
>> >> >>
>> >> >> Don.
>> >> >
>> >> >
>> >>
>> >
>> >
>>
>
>

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