Thanks. I finally figured it out. However, I noticed that the file creation
time on Mac OSX Lion is one hour faster than the local time converted from
time.localtime(time.time()). Could this be corrected or I just missed
something?

Farley

On Tue, Jun 19, 2012 at 11:00 AM, <[email protected]>wrote:

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> Today's Topics:
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>   1. Timestamp in JustFATLogging (Farley Lai)
>   2. Re: Timestamp in JustFATLogging (steve ayer)
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> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 19 Jun 2012 09:05:26 -0500
> From: Farley Lai <[email protected]>
> To: "[email protected]" <[email protected]>
> Subject: [Shimmer-users] Timestamp in JustFATLogging
> Message-ID:
>        <CABDPnOVDkFDd45d73Wqqqudjzj1OfZs=esnc8xgkt7yrx_n...@mail.gmail.com
> >
> Content-Type: text/plain; charset="utf-8"
>
> Hi, all,
>
> I built and ran JustFATLogging on the Shimmer2r motes. However, I have
> questions about the format of the binary data saved by JustFATLogging.
>
>
>   1. what is the endian of the unsigned values and timestamps?
>   2. the system time in seconds seems greater than 16bits. If we set the
>   CURRENT_TIME to build the program, what is the size of the timestamp in
>   bytes the application will write to the storage?
>
>
> I assume everything is unsigned 16bit little-endian integers and print the
> start of the first saved binary file (000) in the format "timestamp, (x, y,
> z)".
>
> ts: 2194, (1929, 2798, 2209)
> ts: 1949, (2826, 2198, 1959)
> ts: 2783, (2257, 1950, 2745)
> ts: 2274, (1915, 2828, 2265)
>
> The CURRENT_TIME is set to about 1340092314.0. Nonetheless, I cannot see
> anything to do with the time. Could anybody help clarify this?
>
> Thanks.
> Farley
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> ------------------------------
>
> Message: 2
> Date: Tue, 19 Jun 2012 10:16:08 -0400
> From: steve ayer <[email protected]>
> To: Farley Lai <[email protected]>
> Cc: "[email protected]" <[email protected]>
> Subject: Re: [Shimmer-users] Timestamp in JustFATLogging
> Message-ID: <[email protected]>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> hi farley,
>
> the format of the file is a repeated tuple of (accelx, accely, accelz)
> binary 16-bit integers.
>
> the file contains no timestamp.   CURRENT_TIME is used to orient the
> filesystem so that it has some idea of reality when it dates the files;
> it's the standard unix time, or "seconds since epoch" (that's jan 1,
> 1970 0000 UTC).  size is time_t, or 32 bits unsigned.
>
> if you want runtime-current timestamps, then you need to run the
> companion version of this app hosttimelogging, which is in an adjacent
> directory.  that uses the host machine to set the shimmer's time while
> in the dock, and it will be persistent between resets (yes, programming
> resets the device).
>
> i hope that this helps,
>
> steve
>
> On 06/19/2012 10:05 AM, Farley Lai wrote:
> > Hi, all,
> >
> > I built and ran JustFATLogging on the Shimmer2r motes. However, I have
> > questions about the format of the binary data saved by JustFATLogging.
> >
> >  1. what is the endian of the unsigned values and timestamps?
> >  2. the system time in seconds seems greater than 16bits. If we set the
> >     CURRENT_TIME to build the program, what is the size of the timestamp
> >     in bytes the application will write to the storage?
> >
> >
> > I assume everything is unsigned 16bit little-endian integers and print
> > the start of the first saved binary file (000) in the format "timestamp,
> > (x, y, z)".
> >
> > ts: 2194, (1929, 2798, 2209)
> > ts: 1949, (2826, 2198, 1959)
> > ts: 2783, (2257, 1950, 2745)
> > ts: 2274, (1915, 2828, 2265)
> >
> > The CURRENT_TIME is set to about 1340092314.0. Nonetheless, I cannot see
> > anything to do with the time. Could anybody help clarify this?
> >
> > Thanks.
> > Farley
> >
> >
> > _______________________________________________
> > Shimmer-users mailing list
> > [email protected]
> > https://lists.eecs.harvard.edu/mailman/listinfo/shimmer-users
> >
>
>
>
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