Thanks again, actually I have a software background and I'm not very good in this soldering thing, especially with this small board and limited tools we have in our lab. I'll try these ways and I'll tell you what happens.
Mohammad 2009/12/23 Paul Johnson <[email protected]> > Mohammad, > > Yes, I believe the problem is with the actual connector that is MMCX > adapter soldered to the board, i've had problems with them coming completely > off the board and taking the PCB lines with them. I would first try > re-soldering that piece first. If this doesn't work, then an alternative > solution would be to use the through-hole connectors for the antenna. It > should be located near the MMCX connector. > > Using the through-hole connectors may be a little bit tricky since the > antennas have an MMCX connector attached to the end. You may want to try > making a very simple dipole(you won't get as good of a performance as the > actual antenna because of impedance mis-matching) using a wire of the > appropriate length, or you can use one of the female MMCX connectors to > interface with the through-hole connector and the existing antenna. > > Let me know what happens, > -Paul > > > On 12/22/2009 10:23 PM, Mohammad S. Hashemian wrote: > > Thanks Paul, you're right, most likely the problem is with the antenna. But > the point is that as you know for Micaz, the antenna is a 2.4 ghz pcb > antenna! how can I re-solder it? by now I've cut the antenna of one of the > motes totally and re-soldered it, but it didn't work and also I resolder > another mote (without cutting the antenna first, just by adding more solder > to it board), but it didn't work either! any suggestions how can I do it? > > And also do you think if the problem is with the connection between MMCX > female part and board or the female part itself is damaged? (the antenna > should be fine, I tested it by changing a new mote's antenna with a damaged > one, and it still was working fine)! > > thanks again for your help, > Mohammad > > 2009/12/22 Paul Johnson <[email protected]> > >> 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 >> > > > >
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