Hi Janos,

I have done the modifications as you have said and also used the NoSleepC
component of your implementation in tinyos-2.x-contrib repository. But I
don't get tight skew values on a line of 5 iris sensor nodes.

Here are the results after a 15 minute run:

1287678021203:   [nodeid=0x1]   [clock=0x1f3fc724]
1287678021250:   [nodeid=0x2]   [clock=0x1f3fc76a]
1287678021294:   [nodeid=0x3]   [clock=0x1f3fc75d]
1287678021350:   [nodeid=0x4]   [clock=0x1f3fc6ae]
1287678021398:   [nodeid=0x5]   [clock=0x1f3fc47d]

Why am I measuring such big clock skew in this small network?? Any
suggestions?

2010/10/18 Janos Sallai <[email protected]>

> Sinan,
>
> It's not there, but it's not terribly complicated to accomplish. Just
> take a look at TimeSyncC and TimeSync32kC, and based on those, come up
> with your TimeSyncMicroC. As far as I can tell, this is the only file
> you'll need to cook for yourself, you don't need to touch anything
> else.
>
> A couple of notes:
> - On the iris, the interface provided by TimeSyncMessageC that gives
> you microsecond precision packet-level timesync is called
> TimeSyncAMSendRadio.
> - You can get microsecond-precision local time from LocalTimeMicroC,
> however, time will stop when the mote goes to sleep. You will need to
> keep the MCU awake all the time to get FTSP to work properly. There
> are a couple of different ways to do this, for example by having a
> component that provides McuPowerOverride and the lowestState function
> always returns ATM128_POWER_IDLE. You'll need to wire this component
> to McuSleepC.
>
> Janos
>
> On Sat, Oct 16, 2010 at 4:33 AM, Sinan Yildirim <[email protected]>
> wrote:
> > Hi all,
> >
> > I have a question on getting microsecond precision using FTSP on Iris
> > platform. Current version of tinyos 2.1.1 does not include components and
> > modules in tos/lib/ftsp directory  in order to achieve microsecond
> > precision. As far as I know, previous version of tinyos (1.x) had a
> support
> > for getting microsecond precision using FTSP.
> >
> > Has anybody a modified version of the FTSP code for tinyos 2.1.1 in order
> to
> > get microsecond precision global time value? Is it possible to share it
> > here? I want to test this code on a line topology of 20 Iris motes.
> >
> > Thanks for your helps,
> >
> > Sinan.
> >
> >
> >
> > _______________________________________________
> > Tinyos-help mailing list
> > [email protected]
> > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
> >
>
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