GPS Transmitter/Receiver Question

NWCCTV

I would like to make a GPS Transmitter/Receiver for my dog. He is a hound dog and when he picks up a scent he is pretty much gone after it. I have a PMB648 but I am not sure if that would work for this or not. Anyone have any ideas? If I can use the PMB648 I would like to go that route.

max72

You should send the position with some kind of transmitter.
In the past I used a Sim900 module and SMS. The advantage is SMS are sent even in marginal conditions.
The sim modules require a bulky power supply stage (average current is low but peak is extremely high).
Besides the thinkerer's interest probably a child watch with GPS position is cheaper and lighter..
Massimo

GordonMcComb

I don't see why you couldn't see the '648. It comes down to whether you want to parse the sentences at the GPS, or transmit them to your base station, and convert there.

What kind of distances are we talking about? If this is in and around Federal Way, your dog shouldn't ordinarily be more than a few blocks away, right? I mean, there are leash laws there, I imagine, and you can't just have him roaming the streets and parklands all by himself. In that case, I wonder if high-power XBee would work as the transceivers?

If you're talking your dog going off somewhere in the cascades, neither XBee nor SMS will be much good (you won't have cell coverage in the boonies). You need a much stronger transmitter. I'd find the right data transmitter, and worry about the GPS later. Any RF data modem will handle the low baud rates these GPS units use, but they don't all have the same range.

The guy who would likely know what's what is W9GFO. He's a ham, and it helps that he's also in the Seattle area, and would probably be familiar with the range of typical types of transmitters.

NWCCTV

I do take him out to the mountains on occasion, which is what this is needed for. I have him micro chipped so if he wanders too far in town it is hopeful someone finds and returns him or the service finds him. However, if there is something small enough to keep on him at all times I would prefer that. I have a large fenced in yard and he is pretty good about staying within his boundaries but the concern is there. After all, he is a hound dog!!!!

GordonMcComb

Supposedly the XBee Pro, which Parallax sells, has a range of "up to" one mile, with an output of 60 mW. In the woods it's probably less. Therefore, you may need a higher powered (possibly needing license) data transmitter.

Frankly, you may find it easier and cheaper to get a whistle, which most dawg's can be trained to respond to. It's done with yummy treats, you know. They can hear the whistle over several miles, and if conditioned properly, know that when they get to you, you'll have some munchings and crunchings for them. This doesn't help if the animal is injured, of course, which could happen in town or in the woods. Anyway, a transponder may end up being less expensive than the animal control impound fees if they are the ones that catch him. Around here it can cost $100 or more to get your lost dog out of the puppy hoosekow. Even more if he's a repeat offender.

xanadu

How do you shrink it all down to fit in a collar?

I tried putting a 5v battery connected directly to an XBee in loopback on a dog collar. The dog collar was made with a waterproof tube already attached to it. I think it came with a survival kit inside, it didn't fit right. Can't find a link to it I'll keep looking.

GordonMcComb

xanadu wrote: »

How do you shrink it all down to fit in a collar?

You wouldn't. A hound has the mass and girth to wear it on the nape of its neck. Note sure that's comfortable for continuous wear, but it would work for the trips into the woods. Tagg Pet is a relatively low cost (about $100) GPS location collar that is small. It requires cellular phone service, though.

Getting a scent hound to return on call can be difficult, but it's not impossible. It's just important to remember they aren't being disobedient or bad when they run off, but following their "job" in the pack hierarchy. This is what they're meant to do. Personally I'd use the collar only as a last resort. Since towns have cars that can hit dogs, and woods have animal control traps that don't discern between wild and domestic, the best solution is to never let them long out of your sight. Ultimately training to return on call is the best overall solution.

wass

Here's another alternative that will give you much better range.

Hams use APRS, a system that transmits GPS coordinates and call sign (and optional text message) on a 2 meter radio (144.39mHz). There are many stations set up to receive this and plot the location of an APRS transmitters on Google maps and/or you can buy a hand-held receiver to pick this data (Icom, Kenwwod, Yaesu all make them). You need a beginning level (technician) license for this, but that's an easy multiple choice test. There are some small APRS transmitters (for example: http://www.amazon.com/SainSonic-AP510-Transceiver-Bluetooth-Thermometer/dp/B00JLB94IS ) that might be small enough to attach to your dog's collar.

-katie (w2lp)

W9GFO

I would use an XBee pro 900 mHz, it's what I have on hand and should give good range. There are some really small HAM handhelds with built in APRS, not cheap but would work. The smallest package I know of is the SoloShot 2 "tags". You would need to hack them but they are super small, have a wrist strap method of attachment, are waterproof and contain both a GPS and transmitter.

The "best" (longest range) option would be a satellite tracker like Delorme's InReach - I use one of those for hang gliding.

stamptrol

Another possibility which I used with our local middle school's high altitude balloon project was the SPOT Trace reporting gps system. The unit is about $100 and the reporting service is about $100/year. Works like a charm and lets you see the hound's location on a google map from any computer or smartphone.

Cheers,