Comment by Taimur Khan on November 27, 2009 at 12:03pm

Hello Reto
This is the founder of E-shepherd Solutions. Due to your post, suddently my website got 40% more hits in two days:) As you would have seen my interest is in bird tracking, especially small birds, I do not have any idea of the nanoUAV market at all. Any way, just to let everyone know, the first ready production batch of the 1.5 Gram datalogger will be ready in the first week of January. The prototype is on my desk and it looks and works great. The logger itself is very fragile, I am not sure about how it will take to the vibration within a flying environment. Any way.. looks like quite a geeky place (my type) so i'll have a look around and see if I can contribute

Cheers

Comment by Morli on November 27, 2009 at 12:17pm

Good Job Taimur , pls let us know expected price , is there any interface point available in the logger so that it can be used as sensor? Some pictures of the prototype can get you some good ideas in this forum, shrink tube mught be used as logger caseing.

Comment by Taimur Khan on November 27, 2009 at 12:33pm

Hi Morli, The GPS can be in two modes. In one mode it is always ON taking one data log per second. In other mode it is duty cycled to save power. I have setup the prototype tag on logging once every 30 seconds using 170mAH battery and no solar cell (total weight 4.5g) for testing and it has been more than 24 hours and it is still going. As soon as it stops, I'll bring it in and take some photos for you ppl. In both these modes there is NMEA data coming in on the pins but the voltage is 3.3V, are you happy to interface with it? Problem with shrink tubing is that the solar cells I am using are quite fragile and they are slightly bigger than the tag so they have tendency to break. I tried to reinforce them with epoxy but the weight just grew many folds.

The price is £300 each for orders less than 10 and £250 each for orders of 10 and above. I can do a special price if you are engineering minded and do not need any support and will not ask for support.

Comment by Reto on November 27, 2009 at 3:54pm

Hi Taimur,
Sorry for the sudden traffic increase you got, it was not intentional. A buddy bird watcher asked me about any tracking possibility for a 30g bird which seems to have a curious behavior, the couple leaving their pups for up to two weeks, flying down to North Africa from Switzerland, and coming back. During the parent's absence, the pups fall in a state of minimal metabolism and survive the lack of feeding! Moreover, those birds do not land most of the time, sleeping in flight for a few seconds at a time! So the tracking would be for a smallish bird sleeping in flight over the Mediterranean see!!! A perfect challenge for your gear.
By the way, when those bird accidentally land on the ground, their legs are too short in relation to wingspan and they cannot take off without finding some elevated spot. I had such a crashed bird in my hands at my office one day for a moment and could test it's internal gyroscopes: rolling the body of the weak bird from one side to the other, the head keeps perfectly immobile. It was a very impressive learning experience for me. As to the bird, it must have been happy when I could throw it to be airborne again. It probably climbed to some altitude to take a nap!
Good luck with your product which still astonishes me.

Comment by Taimur Khan on November 28, 2009 at 4:14am

Hi Reto
The 30g bird behaviour is quite interesting. It is amazing how these birds can do so long migration. Some really good work has been done in the States by the Smithsonion Institute, where they attached BAS geolocators to song birds and tracked thier migration to Brazil and back. Some of the latest studies in tracking small bird and large insects (like dragon flies etc) is suggesting that the 5% boday weight ratio is no longer applicable for tiny birds. In large birds, they are able to counter this extra weight by eating more and building up body weight, but in small birds are not able to do this well , also small birds have a very precise way of sheading/storing heat in thier body which gets disturbed if you attach any electronics to it and will hamper its long term migration. So while I was developing this tag and was being told that weight is the only issue, now it turns out that size is also very important as well as attachment methods.
I have been very lazy lately and didnt take a photo but I will take it and post it here when I can. Thanks TK

Comment by Reto on November 28, 2009 at 4:44am

Thanks for the information, Taimur. I'll transmit that to my buddy coming week. I'm eager to see your pics. Hope you got a macro lens ;-)

Comment by Taimur Khan on December 1, 2009 at 5:29pm

Hi
Here are some images of the 5gram tag including battery.

sorry if these are too large

Comment by Morli on December 1, 2009 at 5:45pm

@ TK,
pls place any thing with well know dimensions like coin or scale next to mini GPS logger so that we can appreciate the miniaturization. BTW is the wire sticking out an GPS antenna? the gray portion in the first pic a solar panel you were talking about? thanks for taking time to put out the pictures. :)

Comment by Taimur Khan on December 1, 2009 at 5:53pm

Yes the wire is the thinest wire I could find as antenna. It can be even thinner than this. In tests, it has proved to work much better than a ceramic chip antenna. The grey portion is the back of the LiPo battery. This pic does not have a solar cell. Let me find a really large coin to place next to it :)

Comment by Taimur Khan on December 1, 2009 at 6:02pm

I was looking for some coins in my home and could find any, then suddenly I rememebred that my son has a habbit of "storing" coins in the shoe cupboard. So I found some coins, and a 4GB SD card in with the shoes. So here is another photo with a UK 10 pence and a Euro 10 Cent and a standard SD card. may be its not that small at all. Anyway I have been doing some tests and laboursly putting some results in a new section on my website if its of any interest to any one.

by this time you will know how bad a photographer I am, one more reason for not haing any pics on my website, dont want it to look to unprofessional

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