Mohammad,
One thing you may want to check out is the antenna connection to the
micaz board. The board-mounted connector can be pretty fragile and can
be easily broken off if the antenna catches on anything, or you attempt
to remove the antenna by pulling at an angle. What I would do is try to
re-solder the antenna one one of the boards that are malfunctioning and
see what happens.
10cm is about the range I've seen micaz/mica2 nodes work w/out an
antenna connected at all, so the antenna is likely the cause of this
problem.
Hopefully re-soldering the connections fixes this and you don't have to
buy new boards,
-Paul
On 12/22/2009 4:53 PM, Mohammad S. Hashemian wrote:
Hi All
We have run a project using micaz modules. In this project there are 8
nodes which are fixed in a certain locations and 40 nodes which are
carried by different people (some of these motes are in XBow boxes and
some other are just in small pouches). There are 3 motes which are
used as base stations through the environment.
The problem we have now is that the transmitter of the mobile motes
gets damaged after a while. For example we pick a new mote out of the
pack, program it, and give it to one of the people, after a while
(sometimes even after 3 days!!!) the transmitter (either sender or
receiver) stops working.
I realize the transmitter of a mote has stopped working when I don't
receive any signal from it for a couple of days. In this case I test
the mote with CountSend and CountReceive (shipped with XBow MoteWorks)
against another new mote. Usually the result is that either the sender
part or receiver part of the mote has become so weak that the packet
can be transferred only if the motes are less than 10 cm away!!!
further than that the packet either can not be sent or be received.
I've called the company regarding this issue and they told me if the
mote doesn't work with CountSend and CountReceive, you should send
them back here for diagnosis and because by now they are out of
warranty, it costs 100$ per each for diagnosis (The motes have been
bought more than a year ago, but they haven't been used at all).
On possibility was that the motes that we got have been produced using
a bad batch in the manufacture for transmitter, and that's why they
keep dying in work. But it's not very likely because the problem is
just exist with the mobile ones, not with the base stations or with
the fixed motes. Also the currently used motes have been purchased in
two separate orders, and probably two separate manufacturing series.
The other possibility is that they die because of the static
electricity (people are supposed to change the mote's battery every
couple of days). Can it be a reason? But this even happens for the
mobile motes with XBow boxes which they look safe for this. and if
it's the reason, why just the transmitter gets damaged and no other
part in the mote?
By now we have lost more than 30 micaz motes this way and if it wants
to continue we will much more. Does anyone has any idea what can be
the reason and how we can stop it? Any idea is highly appreciated.
Thanks,
--
Mohammad S. Hashemian
Research Scholar/DISCUS Lab
Department of Computer Science
254.2 Thorvaldson Building
University of Saskatchewan
(306)966-1947
_______________________________________________
Tinyos-help mailing list
[email protected]
https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
_______________________________________________
Tinyos-help mailing list
[email protected]
https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
