[Lazarus] Decoding USB sniff data

[waldo kitty]

On 6/4/2010 06:21, Mark Morgan Lloyd wrote:
> Mark Morgan Lloyd wrote:
>
>> So to summarise: work out what class of USB device you've got, inspect
>> the Java, and then (only) if necessary use standard tools on the XML.
>> I believe that all of these are well-understood by practitioners in
>> appropriate fields (but not necessarily by me :-)
>
> Right. So a few minutes Googling takes me to
> http://ubuntuforums.org/showthread.php?p=8439613 which implies that the
> cable has an FTDI converter 1a79:6001 [checks] which Linux 2.6.32 should
> support (older kernels might need a patch). The handheld device is
> serial hence courtesy of __j__:
>
> -----8<-----
> For what it's worth, getting results from the Contour using the serial
> connector is pretty straightforward:
>
> 1. When you plug the meter in and press the "M" button, the device will
> send an ENQ (ASCII code 5) to signal that's it's listening.
> 2. You reply with an ACK (ASCII code 6), saying "send me the next record."
> 3. The device will send you a record. To signal you received it and want
> the next one, send another ACK.
> 4. Repeat until you've exhausted all the records.
>
> The first record you get will be a header of sorts. The next 2 are misc
> information. Everything after that are glucose measurement records (or
> control solution).
> ----->8-----

i would assume (yeah, doncha hate that?) that when there are no more records in 
the device that it would send a NAK to the ACK instead of a record?? the NAK 
meaning there are no more records...

ie: -> == from device and <- == to device

-> ENQ
<- ACK
-> DATA (header)
<- ACK
-> DATA (misc data 1)
<- ACK
-> DATA (misc data 2)
<- ACK
-> DATA (record 1)
<- ACK
:loop
-> DATA (record 1+x)
<- ACK
(increment x)
(goto loop until NAK)
-> NAK (no more records)
(then whatever shutdown code may be necessary)

the above depicting the transfer of only two records of glucose data in the 
device...