"Robert Polding" <r.polding@sheffield.ac.uk> wrote in message
news:y_ednfBXGr-qPS3YnZ2dnUVZ8qfinZ2d@giganews.com...
> Hi,
>
> I've recently started a project developing an application for a PDA that
> reads RFID tags (tags that emit a radio signal containing a unique id
> number, and that can be picked up by a reader). I have been supplied
> with a reader and tags but unfortunately very little information on how
> to actually program it. All I've been told is:
>
> This reader has a standard CF interface. To get the bits into your PC or
> PDA, you must use the same part of your development system as for
> reading other data from a CF card. The meaning of the bits you can find
> in John's e-mail. Please do not forget that different processors might
> need different versions.
>
> The email they're referring to contains the following information:
>
>
> Data format for reading the tags is as follows:
> STX(1BYTE), RFID_ID(4BYTE) totally 5 ASCII characters
> STX is 0x02h
> RFID_ID include 4 bytes, representing a 2 bytes unsigned integer,
> such as ID=10811, the hexadecimal expression will be 0x2Ah, 0x3Bh
> while it can be expressed as 4 bytes ASCII characters: 2, A, 3, B.
> Therefore, the data PC received for a tag with ID=10811 is :
> Expression in ASCII : STX 2 A 3 B
> Expression in hexadecimal: 0x02h 0x32h 0x41h 0x33h 0x42h
> Starting with 0X02h, the following 4 bytes represent an ID number.
>
> Can anyone please help as I cannot understand this. I need to be able to
> read a value into a variable, using VB.NET, but have no idea how to do
> this.
>
> Thanks for your time.
>
> Robert Polding
> The University of Sheffield
>
>
>
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"Robert Polding" <r.polding@sheffield.ac.uk> wrote in message
news:v9udna7Ppt0TQCnYnZ2dnUVZ8tHinZ2d@giganews.com...
> <ctacke/> wrote:
>> If you have to read off the CF bus this is not going to happen in VB. Is
>> it possible? Yes, I can think of how to make it happen, but it's going
>> to be really complex and you have to understand hardware and bus
>> architecture. I'd still do it in C. Tell whover supplied the hardware
>> that you need a driver or it just isn't going to happen.
>>
>
> Thanks for the reply. Do you mean in normal C or would this be possible in
> C#/C++ (i.e. in VS)? We've contacted the manufacturer and are waiting for
> a response regarding a driver.
>
> Robert Polding
> The University of Sheffield.

<ctacke/> wrote:
> If you have to read off the CF bus this is not going to happen in VB. Is it
> possible? Yes, I can think of how to make it happen, but it's going to be
> really complex and you have to understand hardware and bus architecture.
> I'd still do it in C. Tell whover supplied the hardware that you need a
> driver or it just isn't going to happen.
>

"Dick Grier" <dick_grierNOSPAM@.msn.com> wrote in message
news:e9uf2ykPHHA.4244@TK2MSFTNGP04.phx.gbl...
> Chris,
>
> The only RFID readers that I have seen are simple serial port devices.
> They plug into the Compact Flash port (I suspect they are built around
> Socket's OEM serial product).
>
> Dick
>
> --
> Richard Grier, MVP
> Hard & Software
> Author of Visual Basic Programmer's Guide to Serial Communications, Fourth
> Edition,
> ISBN 1-890422-28-2 (391 pages, includes CD-ROM). July 2004, Revised March
> 2006.
> See www.hardandsoftware.net for details and contact information.
>

Dick Grier wrote:
> Hi,
>
> This is a serial protocol, and it is straight forward to decode (I have
> examples of similar in my book), What your vendor has to furnish you is the
> port number (almost certainly 4), and the speed (almost certainly 9600 bps).
> You can use the SerialPort object in VS2005, or download either CFSerialIO
> from my homepage or use the OpenNETCF.org serial object to read the data.
>
> If you have specific implementation questions, you can reach me by email and
> I'll try to help.