Super ultra mega urgent - Device ID

[Guest]

I was under the impression that the device id mentioned at the link at the
bottom of the post was unique for the hp ipaq 2210/2215 in the process of
preparing my product for shipping I came across two units with the same
device id. Did I really mess up or did I receive defective units? Any help
would be GREATLY appreciated. Thanks in advance, Scott

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnnetcomp/html/retrievedeviceid.asp

 

[Neville Lang]

Scott,

What I have found in practice is that the inclusion of DeviceIDs in
different brands of Pocket PC depend entirely on whether the OEM actually
puts them in. Some OEMs still do not supply DeviceIDs. However, my
experience is that HP iPAQs always supply a DeviceID. Once again, if the OEM
does put in a DeviceID then it is up to them as to what numbers they use.
Typically, it should be a unique number for each Pocket PC.

The DeviceID is really made up two IDs, a Platform ID and a Preset ID. I
understand that the OEM can make the DeviceID any length but so far it seems
that OEMs do stick with the Microsoft guideline of a 16 byte ID, typically
broken up as 10 bytes for the Preset ID and 6 bytes for the Platform ID. The
paper you referenced by Neil Cowburn, allows you to extract the 16 bytes and
covert this to a GUID which is also 16 bytes.

My understanding is that the Platform ID (6 bytes) is usually the same for a
brand of Pocket PC, like HP iPAQs, whereas the Preset ID should be unique to
each Pocket PC on that platform.

The best way to check for unique numbers is, in debug mode, to check the
bytes in the OutputBuffer, in the code in that paper, before the
OutputBuffer gets modified to a GUID format. I would expect the two iPAQs to
give you the same Platform ID but different Preset IDs.

Regards,
Neville Lang

 

[Guest]

I checked the output buffer before formatting it and they definately are the
same. What I ended up doing is putting a file with a guid in it on all of my
handhelds and using that as the device ID. Thanks for your help.