Using invisible dog fence as boundary for lawn mower robot

[srowshan]

Hi all, I've been working on a lawn mower robot. I have it running and mowing fine. But I need to somehow set a boundary for it. Given that I already have a Dogwatch wire fence for my dog, I'm trying to leverage it. I've seen multiple topics on this forum discussing this topic, but couldn't find what I am looking for. According to the documentation my Dogwatch transmitter sends a an FM 8 KHZ signal. It can be also set to send the signal in FM, or at 4 KHZ AM or FM.

I've been looking for a pre-built Arduino compatible AM or FM receiver that can pick up this signal. I've had no luck finding one, and I'm not familiar with radio circuits or very low frequency receivers. And I ideally need something prebuilt. Any help is appreciated.

Regards,
Mak

[CrossRoads]

That's pretty low frequency. Can you get a replacement collar and use that as the sensor, use the 'tickle" output and turn before you reach the 'full shock' distance?
Or, turn at the 2nd one I guess, depending on how close it is to sidewalks & stuff.

[BulldogLowell]

That's pretty low frequency. Can you get a replacement collar and use that as the sensor, use the 'tickle" output and turn before you reach the 'full shock' distance?
Or, turn at the 2nd one I guess, depending on how close it is to sidewalks & stuff.

Don't make your lawnmower too intelligent.  My dog figured out that it can run the batteries down by standing close to the boundary.  When the sound/vibration warnings stop, the darn dog walks across the fence.

[CrossRoads]

Mine would do similar - sneak forward, and if no shock he'd roam for the day - and then come home before we did so we wouldn't know he'd been gone unless someone ratted him out!

[srowshan]

Hi all, I've been working on a lawn mower robot. I have it running and mowing fine. But I need to somehow set a boundary for it. Given that I already have a Dogwatch wire fence for my dog, I'm trying to leverage it. I've seen multiple topics on this forum discussing this topic, but couldn't find what I am looking for. According to the documentation my Dogwatch transmitter sends an 8 KHZ FM signal through the wire fence. It can be also set to send an AM signal 4 KHZ or 8 KHZ.

I've been looking for a prebuilt Arduino compatible AM or FM receiver that can pick up this low frequency signal. I've had no luck finding one, and I'm not familiar with radio circuits or how to detect very low frequencies. And I ideally I need something prebuilt. Any help is appreciated.

Regards,
Mak

[srowshan]

That's pretty low frequency. Can you get a replacement collar and use that as the sensor, use the 'tickle" output and turn before you reach the 'full shock' distance?
Or, turn at the 2nd one I guess, depending on how close it is to sidewalks & stuff.

Unfortunately the replacement collars are very expensive (over $150.) So I was hoping for a less expensive solution.

[srowshan]

That's pretty low frequency. Can you get a replacement collar and use that as the sensor, use the 'tickle" output and turn before you reach the 'full shock' distance?
Or, turn at the 2nd one I guess, depending on how close it is to sidewalks & stuff.

Don't make your lawnmower too intelligent.  My dog figured out that it can run the batteries down by standing close to the boundary.  When the sound/vibration warnings stop, the darn dog walks across the fence.

Fortunately my dog is not that smart! The fence is working fine for her!

[BulldogLowell]

there are lots of posts on this subject...

Here's one

[rogerClark]

Can you send us a link to the DogWatch system ?

You said that the fence sends out 4khz, which implies that there is some sort of receiver

Does the dog wear a collar which detects the 4hkz and bleeps etc on the dog when it gets close to the fence

Or does the dog wear something that causes the fence controller to know that the dog is near the fence

Or does the system not need any other hardware, ie is it sensing body mass etc possibly by capacitive coupling ??


If its a system where the dog wears a detector, the simplest solution is to buy another dog collar detector and take it apart and connect the arduino to where the LED or buzzer etc was connected

However I suspect its more complicated than this ;-(

[srowshan]

there are lots of posts on this subject...

Here's one

Yes, I've seen this one and some others. Most use a replacement collar/receiver. In my case that is very expensive. So I'm looking for an alternative solution.

[CrossRoads]

$150? Wow. I bought a whole system for less that.
http://www.homedepot.com/p/PetSafe-Innotek-Wired-1-3-Acre-In-Ground-Dog-Fence-SD-2000/100660387
Scroll down - extra collar $50

http://www.homedepot.com/p/PetSafe-10-Acre-In-Ground-Pet-Containment-System-RF-3004W-11/100382345
http://www.homedepot.com/p/PetSafe-1-2-sq-ft-Wireless-Receiver-and-Collar-IF-275/100349982

[lar3ry]

http://forum.arduino.cc/index.php?action=post;topic=245228.0;num_replies=1

[CrossRoads]

Please Don't CrossPost. If you don't like the subforum the topic is in we can move it.
One topic, one conversation.
Thanks
Moderator

[keeper63]

Have you tried using the receiver portion of a cheap "wire-tracer" tool - example:

http://www.harborfreight.com/cable-tracker-94181.html

Such a device might be able to pick up the signal that your virtual fence transmitter is outputting, and you could then use the presence of that signal (and/or the strength) to determine where your robot is in relation to the boundary wire.

Might be worth purchasing and trying it out - worst case is that you are left with a wireless signal tracing tool (which are pretty useful on their own for tracking problems with wiring you can't see easily).

[Jantje]

Have you tried using the receiver portion of a cheap "wire-tracer" tool - example:

Good thinking
May be a add-on for my mowrobot later.
Best regards
Jantje