Finding a rabbit with a PICAXE...

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jsimpson001

Member
No this isnt some cruel method of bunny execution, its a serious problem...

I have a rabbit (called Nesbit) that likes to run around in our garden, which is about 60x40 metres square, with lots of bushes and holes in the fences. I woulkd like to create some sort of 'tag' to strap onto the rabbit in order to find it. Im just looking for ideas at the moment, such as a handheld RF transmitter which would cause the module strapped to the rabbit to produce a loud noise to allow me to locate it. any ideas...?
 
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Brietech

Senior Member
you could go a couple different routes with this one.

1) short range transmitter that basically alerts you if the bunny has escaped (transmitter has gone out of range of the receiver)
2) Just a periodic buzzer, although that might scare the bunny
3) Using a series of short-range (a couple feet) receivers stationed around the yard, and a short range transmitter on the bunny, you could have some sort of elaborate tracking system that would silently show you the vicinity of the bunny.

4) Reeeally complicated, but you could build a tiny, adorable GPS backpack w/ transmitter for the bunny, and let it wander wherever it pleases.

sounds like a fun project!
 
J

jsimpson001

Member
Hi, thanks for your suggestions, I think that the best solution would be about 6 rf receiver modules on posts about 1m high positioned around the edges of the garden, with a medium range transmitter on the rabbit which emits a signal every minute or so, which is recieved by all the receiver modules, then send the data via radio to a datalogger module connected to a pc, which compares the times each signal was recieved allowing an approximate distance from each reciever to be calculated, placing the bunny where the distances overlap. Though it would be very difficult to guage the distances from very very small time differences...

would this be a suitable transmitter?
<A href='http://www.rapidonline.com/productinfo.aspx?kw=rf%20transmitter&amp;tier1=Electrical+%26+Power&amp;tier2=Security+%26+Warning+Device&amp;tier3=AM%2fFM+System+%26+Modules&amp;tier4=AM+remote+control+transmitter&amp;moduleno=32432' Target=_Blank>External Web Link</a>

Edited by - jsimpson001 on 05/02/2007 09:19:36
 
E

eclectic

Moderator
JSimpson.
That module would work and the programming
is fairly easy.
The transmitter could be located by well-established methods.

Look up RDF Radio Foxhunt or TDOA

Here&#8217;s two sites, of many

http://utaharc.org/rptr/ark_df_desc.html

http://webhome.idirect.com/~griffith/tdoa.htm


But, and a serious &#8220;but&#8221; is the whole transmitter unit.
(tx / circuit board /batteries.)

1. How would you attach them safely and securely?
2. Any collar method could pose strangulation problems!

e.

 
D

Dippy

Moderator
With all the Rabbit Health caveats assumed, ecletrics RDF suggestion is better.

I you are hoping to make an inverted GPS system with RF you will be wasting money. You've obviously looked at the maths, SOL and all that. And you've obviously realised that the time differences over short distances are miniscule.

BUT one thing you may not know is that RX devices do NOT have consistent RF-in to logic High, so your timings would be all over the place. Nice idea - but please keep your cash in your pocket.

As an aside: if you want to test that multi-Rx method use U/s. But perhaps not on the poor old rabbit.

At this rate it will be cheaper to put up a decent fence. However, good luck.
 
hippy

hippy

Technical Support
Staff member
That cost is probably why farmers run a cheap bit of wire round their perimeters and put an 'electric shock' through it.

I think you possible have two different issues; finding the bunny when it's still in the garden and is hiding, and when it's made a break for it towards a neutral country.
 
J

Jeremy Leach

Senior Member
Just been wondering...

Is it possible to have a very sensitive electret mic with a notch filter etc that could respond to a specific 'where are you' sound? With added complexity if necessary to make triggering reliable.

If so, then could have a unit generating the sound (I imagine a short, loud beep from a powerful piezo). The unit on the rabbit, would then respond by generating a response sound.
 
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Dippy

Moderator
You would have to whistle very loudly (and have very good hearing) if the rabbit was a hundred yards away.

I was joking about the fence btw.

1. Cheap chicken wire across the holes in fence.
2. Train the rabbit.
3. Overfeed rabbit so it can't fit through holes in fence.
4. Tell the rabbit not to run away.

Seriously though, a radio bleeper plus servo controlled RDF antenna sounds good.
Or maybe a very short range transmitter which can be detected by a loop wire running outside the fence. So if Bugs Bunny gets within a foot of the wire it gets detected.

Anyone remember Monty Python?
 
J

jsimpson001

Member
GREAT idea Dippy, im going to have to get 150 metres of wire from somewhere though. I might try a combination of rotating antenna to sense direction and Dippy's fence wire antenna but that means ill probbably need two transmitters on the bunny, both at different freq.

I hope the neighbours dont think im setting up a UFO spotting antenna with rotating coathangers... :)
 
lbenson

lbenson

Senior Member
How about your original idea--with 433mHz transmitter in your hand and receiver on bunny with piezo buzzer? 08Ms both places. It doesn't keep the bunny in the yard, tho. There's also the buried wire shock collar method used for dogs, pace PETA.
 
J

jsimpson001

Member
I dont really want to electric shock Nesbit, that would be a bit cruel. Also im feeling a but more inclined towards a way of keeping the rabbit in the garden.
 
Technical

Technical

Technical Support
Staff member
<A href='http://www.jokesunlimited.com/funny_halloween_costumes/large/carrot.jpg' Target=_Blank>External Web Link</a>

Edited by - Admin on 13/02/2007 20:23:29
 
C

crumpybrown

New Member
I just became a vegetarian!

Why not a weaker Tx on Bunny, with multiple antennae positioned around the garden, and compare not the signal delay but rather field strength at each antenna? Sorry if this has already been suggested.
 
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Brietech

Senior Member
On that same note, if the transmitter is weak enough (i.e. a couple of feet), only 1-2 posts will be able to see it at any time anyway, so you get free location tracking
 
D

Dippy

Moderator
Range of 2 feet (ish)? [Not Fetish].
That means you'd need an antenna/Rx at 4 feet intervals around perimeter. Cheap - not.

Fix the fence Mate, keep Nesbit under control ... and think of another PICAXE project.

Edited by - Dippy on 06/02/2007 08:49:06
 
hippy

hippy

Technical Support
Staff member
No idea if or how this would work or be done, but what about a criss-cross of wires dividing the garden into squares and scanning the matrix to identify which Nesbit is in ? A bit like how touch screens do their job on a larger scale.
 
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Jeremy Leach

Senior Member
How about an automated PICAXE-controlled pea-shooter that sprays the area with fire until you hear the scream, at which point you log the coordinates the pea-shooter was pointing ...just joking and sorry for the SPAM post <img src="wink.gif" width=15 height=15 align=middle>
 
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Fowkc

Senior Member
If the trouble with radio tracking is that the time differences are too small to accurately determine location, what about using ultrasonics?
 
D

Dippy

Moderator
I think the easiet way would be to wire up several million QTC pills with a cascade of multiplexors.

Or... fitting Nesbit with an atomic clock and high power Rf Tx unit. Then launch an array of orbitting satelite receivers suitably equipped. Then perhaps a microwave downlink to your O8M breadboard (specially constructed and flown in by Stan) with a digital display - I'm sure you can get a cheap LCD to save costs.

PS. Usng high-power ultrasonics may:
a) cause Nesbit to go deaf
b) Attract packs of sheepdogs towards Nesbit, which, would also be injurious to her health.



Edited by - Dippy on 06/02/2007 12:50:38
 
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Fowkc

Senior Member
According to this site: <A href='http://www.lsu.edu/deafness/HearingRange.html' Target=_Blank>External Web Link</a>
Rabbits have a hearing range of 320 to 42000Hz, so 40kHz ultrasonics would be heard by the rabbit.

However, if the ultrasonic transmitters were located on posts in the garden, and the receiver on the rabbit, location could still be determined, and sent from the rabbit via a radio link. Brief low-power pulses every minute or so would be unlikely to affect the rabbit, probably?

Edited by - Fowkc on 06/02/2007 14:15:14
 
D

Dippy

Moderator
How will the Rabbit receiver (RRx)know which U/S Tx transmitted? Coded U/S? How will the U/S RRx know when the pulse was transmitted to calculate time delay? RF as well?
What happens if 2 U/S doo-dahs transmitted at same time? RF Network between U/S Txs to prevent 'collision'?

Will you use a rotating U/S receiver or an array?

Like Nesbit, I'm all ears! LOHL.

Will Nesbit be fitted with tow-bar and trailer to hold electronics and batteries?

A large trailer will prevent her getting through holes in fence and slow her down if she tries to make a bolt for freedom.

I wonder how long this thread will get? I'm going to phone Stephen Hawking to get his opinion. I need to see him anyway so I can swap his voice-chip for a Liberace simulator.

PS. This thread was entitled &quot;Finding a rabbit with a PICAXE...&quot;.
I didn't know they were interested in electronics!

Edited by - Dippy on 06/02/2007 16:55:33
 
R

Rickharris

Senior Member
<BLOCKQUOTE><font size=1 face=arial>quote:<hr height=1 noshade>
o one so far has mentioned a fixed length of string :) <hr height=1 noshade></BLOCKQUOTE></font><font face='Verdana, Arial, Helvetica' size=2>
or a cage - Faraday or otherwise.
 
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flyingnunrt

Senior Member
I was going to mention the string thing but..
Do you know how crop circles are made?
Rabbit on piece of string anchored to a carrot.
My only other suggestion would be to get yourself a Border Collie.
 
S

SD2100

New Member
With the string idea, have one end on bunny and the other end on an electric winch, push the button and bunny comes home. The winch could be remote controlled by picaxe from your lounge chain so you can keep watching your favorite show. The only draw back is if bunny has been hopping around and getting fairly tangled you will end up with a half dozen shrubs, the garden hose the wheel barrow and the remains of the garden fence on your door step, oh and bunny on the end of it. :)
 
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Fowkc

Senior Member
For the ultrasonics, I was thinking four linked transmitters at the corners of the garden (expensive, I know), controlled by a PICAXE.

The first transmitter sends a pulse. After a seconds wait, so does the second, then the third, then the fourth. The difference in distances will correllate with deviations from those 1second pauses at the rabbit.

This could be done with three transmitters, or even two, but will progressively less accuracy.

The main problem (of many) will be making the receiver omnidirectional, and fitting all this into a package small enough for Nesbit.
 
J

Jeremy Leach

Senior Member
Don't rabbits thump the ground when alarmed? If so could clap your hands and then have (PICAXE controlled) seismic detectors picking up the thump and triangulating position...

?

Edited by - Jeremy Leach on 07/02/2007 09:28:46
 
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toxicmouse

Senior Member
well, if you live in a fairly cold climate you could use this problem to justify buying an infrared scope or binos. bunny body heat would show up nicely i should think.

how about attaching an RFID tag on the bunny, walking though the garden with a detector would give you a fair idea of the whereabout of said elusive pet.

record the noise made by Nesbit when he eats in his favourite cabbage patch. play the sound near your back door to call him... effectively make a noise like a cabbage.

i feel some realy silly ideas comming on, so i will stop here.
 
D

demonicpicaxeguy

Senior Member
i looked into this a while ago wth my cat as i wanted to see where exactly she adventures off to during the day

one of the best solutions i came up with it to stick a transmitter and reciever on said cats collar then.....

have three transmitter and reciever stations based literally in a triangle and they simply take it in turns to transmit a short beep and time how long it take to beep back

then by using some year 8 maths and some panadol a simple vb program should be able to work out exactly where said is unfortunatly said cat died before i was able to actaully do this and never ended up doing it... but i'm getting inspired as there are a few fellow employee bludgers i want to track
 
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Dippy

Moderator
DPAG, that sounds good.
What sort of time delays are we talking about? i.e. roughly how long?

And how did you measure the time delay?

What sort of radio modules did you use? (or think about using?)

CAn you explain a bit more how you system was going to work?
 
B

BeanieBots

Moderator
I too would be VERY interested in how you did it.
That is THE Holy Grail of robotics location, short of resorting to atomic clocks and the like.
 
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