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By Mosha
#62353
Hello Sparkfun! I have to say that I'm very excited to be a part of this community. Although, maybe I'm not part of it until I contribute?..

Anyway, I would like to build a GPS data logger for my dog. Although i always know how far I go (thanks Forerunner 405), it seems to me that Bob Dylan (my dog) goes a lot further. Back and forth, out and back, etc, etc. He's also terribly fast, but that's only relative to my own speed (not terribly fast). So, here's what I'm thinking:

Dog Collar:
- A GPS Reciever (Sparkfun# GPS-00465)
- Power Source (Suggestions?)
- xbee 1mW (Sparkfun# WRL-08665).

Receiver:
- xbee 1mw (Sparkfun# WRL-08665)
- Arduino (maybe the mini)
- SD Card

So i have some questions: Can I hook the GPS unit directly to the Xbee? or do I need some sort of controller to tell the GPS unit where to pipe the GPS data? What are my options for the reciever end in terms of writing the data to an SD card? is this something the arduino nano can take care of?

This is my first electronics project, but I think it's totally do-able. I look forward to hearing your suggestions! Thanks in advance :)
By Krogoth
#62453
Why not just have the SD card on the dog collar? Unless you want the location of your dog sent to you in real-time (and without a screen this isn't much use) the wireless system just seems like added complexity.

For the ideal power solution, you'd use one of Sparkfun's small Li-Poly batteries, and perhaps the MAX1555 to charge the battery from a USB port or wall wart. To write to an SD card you would probably want to lever someone else's solution (there are plenty available from Sparkfun), since writing data to FAT32 is not trivial but it has been solved by others.

Will.
By Mosha
#62471
Will, thanks for the reply!
My original idea was to actually have this be a self contained unit. However, I looked at what I thought I would need
- Arduino
- GPS
- Arduino SD shield

It seemed like it would be really bulky around my dogs neck. So, if I only put the GPS, Powersource and xbee, it might be a bit more manageable. I've been imagining an enclosure a little smaller than a soup can.

I think at this point I just need to pull the trigger and order the parts. If it's too big, I can adjust and make the reciever, but just starting with a self contained unit seems like the best idea.

I'll post back with anything interesting. HAPPY NEW YEAR!
By stevech
#62499
The XBee (and any other low power unlicensed 2.4GHz product) won't give you enough range - say, 400 ft with ideal line of sight, less with obstructions.

The commercial products that do this use cellular data modems.

Not as hard, but you'll need to have firmware that really works to conserve battery consumption by GPS.

If you're a novice at all of this, I'd suggest a less ambitious project!
By trialex
#62512
Mosha wrote:Will, thanks for the reply!
My original idea was to actually have this be a self contained unit. However, I looked at what I thought I would need
- Arduino
- GPS
- Arduino SD shield

It seemed like it would be really bulky around my dogs neck.
Not sure what exact products you meant by "GPS" and "Arduino SD shield", but ladyada's GPS shield has the SD card connector on it, and using her libraries, you can write the GPS data to the SD card.

http://www.adafruit.com/index.php?main_ ... ucts_id=98

So your item list will be

Arduino
GPS shield (+GPS module that plugs into shield)
GPS antenna
Battery
By Krogoth
#62660
I totally agree with trialex's solution to this problem - you will not be required to design or solder any circuit boards, since the three primary devices are already assembled (GPS, microcontroller and SD card). Also, presumably there is example code to both parse GPS sentences and write to the SD card, meaning you can lever off that solution. All that is required are some batteries (even alkalines would do fine) and an enclosure, and some software development.

Will.
By Mosha
#63926
Just to keep anyone interested up to date: I have ordered the GPS shield from adafruit along with a minty boost to power the device. Right now I'm going with a self contained unit as Krogoth suggested. Does anyone have a suggestion as to what sort of antenna I can get for the EM-406A GPS Module?

I finished writing the software to googlemap (verb?) the GPS strings along with log some basic information (total distance, max speed, etc) over the weekend. So i'm just waiting for the hardware to arrive and this project should be done :)

To make it interesting I also think I'll try my hand at vacuum forming an enclosure. I have a DIY CNC mill in my basement which I'll use to mill out a block of foam shaped like the Arduino + GPS Shield + mintyboost, then form some plastic around the foam.
By huh
#64891
While I can't comment on the antenna I can say that the best way to house them is with the batteries and GPS, etc. housed at the bottom of the collar and then the antenna cable runs within (i.e. through) the collar material to the top where the antenna is house. This will keep the antenna in the best orientation. You might also want to consider a suede like leather over some foam or even a bike inner tube on the inside of the collar to keep it from swinging. You can check out how the pros do it, for example http://www.lotek.com/gps4400.htm Hope that is helpful, maybe not.
By stevech
#64956
Mosha wrote:Just to keep anyone interested up to date: I have ordered the GPS shield from adafruit along with a minty boost to power the device. Right now I'm going with a self contained unit as Krogoth suggested. Does anyone have a suggestion as to what sort of antenna I can get for the EM-406A GPS Module?

I finished writing the software to googlemap (verb?) the GPS strings along with log some basic information (total distance, max speed, etc) over the weekend. So i'm just waiting for the hardware to arrive and this project should be done :)

To make it interesting I also think I'll try my hand at vacuum forming an enclosure. I have a DIY CNC mill in my basement which I'll use to mill out a block of foam shaped like the Arduino + GPS Shield + mintyboost, then form some plastic around the foam.
I use OEM module GPS receivers that have an integral antenna.

You're going to need software to enable power saving sleep modes and this gets complicated. Else you can run around behind the dog with a box of batteries!