i had te following idea as a project.
my dog likes to run away and we bought an electric collar. this uses a wire in the ground to mark where the dog can go.
however the wire breaks frequently and i live on a farm so it's a big surface.
now i am thinking about making a collar myself but instead of using a wire i wanna use a gps component.
do you guys/girls know a good and cheap gps module that's accurate enough (like 1m max) ?
i prefer something cheap to start with
The GPS modules currently available have positional accuracy of about +/- 2 meters in the best of circumstances, and don't work at all in the worst of circumstances, i.e. in heavy forest or canyons.
They are also power hungry and batteries don't last long.
Then there is the problem of how the GPS location will be transmitted from the dog's collar to you.
For general information, consider the SPOT locator or asset tracker.
ow oke the idea thanks
and the idea wasn't to broadcast the location of the animal (at least not at first)
but to give them a small electrical shock when they go outside there permited area
That is certainly doable but battery lifetime is a serious problem. The best handheld GPS units you can buy run for only a couple of days continuously.
Power consumption is an issue for a GPS running all the time.
A Ublox 8 with a decent antenna will still often use between 15mA and 20mA.
Which is only around 2-3 days life even from something like a set of Lithium AAAs.
And accuracy from those GPSs is not often going to be less than 5M.
forget about battery life, for now......
you want the GPS to determine where the dog is,, and then you want a processor to determine if the dog is close to the perimeter of a mapped area,, then shock the mutt if he is..
problem solved,, you hang a full fledged pc around the mutt's neck, tethered to an extension chord, to supply the required power to drive the required storage peripherals,,, and the dog ain't going anywhere.....
But how will the PC know where it is on the map?
pc attached to dog, with gps as peripheral, has map data on associated storage peripherals. pc gets mutt/pc location from gps and analyzes correlation to map data.
although, a decent kennel would probably be a cheaper and more humane solution.
on a more serious vein,, (aw, do I have to...): does your farm have an electrically isolated fence, like barbwire on wooden posts? If so, you could use the lower rung as the antenna wire for the existing 'burried wire' system, or string a bottom rung of 'electric fence' wire (tough and relatively cheap). The antenna for the burried system doesn't have to be buried or that 22 awg stuff,, just isolated from earth ground.
"although, a decent kennel would probably be a cheaper and more humane solution."
Depends how big the dog is. Have you seen the recent TV ad with the dig that brings home all kinds of stuff? Big clump of some plant, plastic pink flamingo, etc.
GPS watches are pretty small, USB plug for charging them up.
Hack one to read position into a uC that is control of matching current location to the virtual line, for beep first, then shock. Or maybe an inexpensive Garmin or TomTom unit with built-in rechargeable battery.
We had underground wire, my dog would push the limit, I guess checking for beeping , if no beeping (discharged battery, one of the 12V LI kind), he'd take off for the day, then be home before us and we'd none the wiser unless a neighbor had ratted him out.