[Tinyos-devel] Testing FTSP

[Branislav Kusy]

Omprakash Gnawali wrote:
> On Tue, Jul 29, 2008 at 9:58 AM, Branislav Kusy <kusy at stanford.edu> wrote:
>>>> these results are really bad, there should be no red crosses after the
>>>> initial synchronization period (first 40-50 seconds). is there a way to
>>> Agree.
>>>
>>>> re-run the experiment (first 500s would be enough) while logging the
>>>> whole
>>>> debug struct(test_ftsp_msg_t)? could i also see the deployment map?
>>> Just so I understand this, I am dividing these attributes into useful
>>> and not useful (log trigger is a periodic timer in my experiment).
>>> Please let me know if you agree:
>>>
>>> Not useful:
>>>             report->counter = rcm->counter;
>>>             report->local_rx_timestamp = rxTimestamp;
>>>             report->global_rx_timestamp = rxTimestamp;
>> looking at the counter vs the local time is very useful in finding out
>> problems in timestamping (code that records time deep in the MAC layer,
>> after receiving SFD interrupt). so i'd include this data as useful.
> 
> Isn't this counter the count value in RadioCountToLeds pkt? If so, I
> don't have this information because I don't run RadioCountToLeds. I
> trigger logging using a periodic timer.
> 
> ...
> 
>> would be a problem. increasing timesync period could be a solution? but
>> first, it would be very useful to see the local time vs counter graph -
>> there used to be a bug in radio stack which would cause wrong association
>> between incoming radio packets and SFD interrupts (timestamps are buffered
>> in a FIFO in CC2420ReceiveP.nc). i haven't seen it in rc3 testing (about 20
>> micaz motes running for an hour, single hop), but i'd just like to make sure
>> before we start tweaking ftsp.
> 
> Maybe we are talking about two different counters?
i see - you are right. localtime and counter are not useful in this 
case. let's just see the useful data you proposed. actually, maybe add 
the global time (it can happen that is_synced is 0 and global time is 
crap). global time won't tell us much about accuracy (you trigger it 
from a timer), but we'll at least see if the error is large (e.g. couple 
of 10s of seconds).

brano