Hi, I am wanting to build a device that will allow me to keep an ‘eye’ on my dogs when I go to my cottage. I often will be busy with outdoor activities and they tend to wonder off. If I had a pair of wireless devices, one to put on their collar and one to have on my person, that would alert me when they got ‘out of range’ then I could relax and enjoy my vacations more.
I don’t expect any one to design this for me but if you could point me in the right direction by telling me what components/breakout/modules would be capable of doing this, I would appreciate it.
Thanks in advance
Mike 2545
P.S. this is my first post on this forum and I thought it would be the right place to ask for this type of help.
Mike2545:
If I had a pair of wireless devices, one to put on their collar and one to have on my person, that would alert me when they got ‘out of range’ then I could relax and enjoy my vacations more.
I've had similar "thought exercises" but so far have not
tried any experiments. In my case I’d like to know
where my cats go, if they are outside. So I’m more
interested in radio direction finding than a run away
dog alarm. Cats are smaller than most dogs, so a
compact collar design is needed. They already have
collars (that can be lost or removed by cat haters),
and they have RFID microchips which I hope we never
need to use.
The “James Bond gadget” would be a collar with GPS
and a Transmitter, to give data for the GPS location,
plus status info about the battery. This could be done
I have only read about this so I can’t give you much specific detail on it. Tom Igoe’s book Making Things Talk has a project called “Reading Received Signal Strength Using XBee Radios”. Using the signal strenght value you could create a a device, an Arduino device for simplicity (I’m pretty sure the arduino could handle this), that would read the value of the strength of the signal transmitting from the dog’s collar. When the signal dropped to the certain level an alarm could beep or light up. The dogs collar would only need to have the xbee unit and some sort of controller to generate a signal. I don’t know much about the xbee units but there might even be a way to set one a unit to transmit a signal by itself.
What would be even cooler is if when the signal dropped to a certain level the dog collar would beep, and the dog was trained to sit when it heard the beep.
timgregor:
I have only read about this so I can’t give you much specific detail on it. Tom Igoe’s book Making Things Talk has a project called “Reading Received Signal Strength Using XBee Radios”. Using the signal strenght value you could create a a device, an Arduino device for simplicity (I’m pretty sure the arduino could handle this), that would read the value of the strength of the signal transmitting from the dog’s collar. When the signal dropped to the certain level an alarm could beep or light up. The dogs collar would only need to have the xbee unit and some sort of controller to generate a signal. I don’t know much about the xbee units but there might even be a way to set one a unit to transmit a signal by itself.
What would be even cooler is if when the signal dropped to a certain level the dog collar would beep, and the dog was trained to sit when it heard the beep.
I hope that can be helpful.
-Tim
But, as I commented earlier, the range of XBees and other low power devices, esp. at 2.4GHz, is shorter than a normal dog’s radius of play, out in the park.
And- rather than received signal strength, which implies the on-dog Xbee is using battery to transmit and something is triggering that, you could have the base station side ping now and then and see if a response occurs. If not, it’s out of range. Or the dog is lying on top of the device since this will greatly attenuate the signal.
I have some questions, and mostly I’m thinking out loud here so if I’m off base just let me know; and I want to thank all of the others that responded to this question. Keep the suggestions coming!
Would the Xbee be able to ping on its own or would it require a micro controller to Send a packet and wait for a response and then give a ACK failure?
What I envision is two micro controllers (AVR or otherwise) hooked each to an Xbee. They would ‘talk’ to each other and when they lose connection the one (on the dog) would beep and the one I have would vibrate.
I could use a RF transmitter/receiver combo but I’m thinking it would be nice to know which dog is out of range, and after reading the spec sheets, these Xbee units look like the are addressable. So the ‘Parent’ unit would know which ‘child’ unit is lost.
Is there another transceiver that would accomplish the same thing?
Thanks for helping me sort this out. One of the first things to getting started in a project like this is identify the right components that will accomplish the objective.
Would the Xbee be able to ping on its own or would it require a micro controller to Send a packet and wait for a response and then give a ACK failure?
The XBee supports IO/ADC passing. Its a mode where it samples the values of I/O and ADC pins (configurable) and sends them out periodically. I suppose you might be able to configure this mode and then save the configuration to its EEPROM and thus subsequently operate without a microcontroller. Never tried it so not sure if it would work. The module is very easy to control with even the simplest microcontroller and you would be much better off with the extra flexibility.
What I envision is two micro controllers (AVR or otherwise) hooked each to an Xbee. They would ‘talk’ to each other and when they lose connection the one (on the dog) would beep and the one I have would vibrate.
Assuming you want to support any kind of reasonable range, the beeper volume required to notify you of a problem would likely not be good for your dogs very sensitive ears (being located only a few inches from them).
Is there another transceiver that would accomplish the same thing?
You should determine what kind of range you need-- that will help with requirements. Digi makes a 900mhz module which is supposed to get 1000 feet outdoors. Still not super high. There are other 900mhz parts with larger ranges.
Note there is a commercial solution for this application. It uses GPS and a 2W transmitter (claims 1-3 mile range). While not inexpensive, 300-400 for the system, I think you may find the engineering required makes this a non-trivial first-project and will cost more than the commercial solution. http://www.roameoforpets.com/products.php
If you build your own solution, I don’t think it will let you relax like you think. Instead, you will spend more time wondering if the system is working properly. With some aspect of your pets welfare relying on it, it becomes a semi-mission-critical application which are much harder to engineer. And of course, good fun the first time your dog takes the electronics for a swim!
Yea the range is good. (small dogs) I just don’t want them wandering off. I suppose putting a bell on them would work but I can see more applications for this. (I dream BIG)
The beeping wouldn’t have to be very loud, Just enough to tell where they are (under the porch, shrubbery, car etc)
A lot of times I will be working on a project and they want to come out and be with me, so 50-100 ft range is perfect for this application.
This is not my first project just my first time posting on this site.
I have done some wireless projects in the past.
example Before the driveway monitors were widely commercially available, I built a battery operated transmitter/ receiver combo to ring a bell in the house; circa 1990.
I can think of several ways to use the RF link available from Sparkfun but I like the X-bee because of the serial capabilities.
As far as being able to ‘relax’ (term used loosely), I would like to test it with the dogs and maybe develop it into another product altogether.
A lot of times I will be working on a project and they want to come out and be with me, so 50-100 ft range is perfect for this application.
For 50-100 feet outdoors, the XBee should work well. I use the XBee Pro inside (through multiple walls) and it works pretty reliably at 60 feet. Given your application is not super time sensitive (dont need to detect in milliseconds), that helps with reliability (you can resend multiple times).
I can think of several ways to use the RF link available from Sparkfun but I like the X-bee because of the serial capabilities.
The XBee is a nice all-in-one package. It has worked well for my applications, though I wish it had a bit more range. I use a combination of XBee and XBee Pro modules. Interfacing via a microcontroller is pretty straightforward. Biggest problem I ran into on my current project was running out of code space. I used a AVR2313 which only has 2K of Flash and maxed it out.
One? Wouldn’t that be like owning one, two-way radio. How is one X-bee going to be able to communicate with another micro-controller?
Actually, Steve was referring to the fact that you want to get the XBee Series One modules (not that you only want one module). These are the point-to-multi-point modules and are the easiest to use. They have part numbers of XB24-A** for the 1mw version (non-Pro) and XB24P-A** for the 63mw version (the Pro version). Big difference between the non-Pro and Pro version are transmit power (1mw for non-Pro, 63mw for Pro), receiver sensitivity (the Pro is better) and power consumption (Pro is significantly higher).
In addition to the XBee Series One, Digi also makes two other versions-- the DigiMesh (previously known as the Series Two) and the ZigBee. These latter two are actually same hardware but with different firmware on the module. While the mesh sounds appealing, at least with their early series two modules, the implementation seemed pretty hokey.
For $99, Digi makes a Series One starter kit (XB24-DKS-INT). It includes two XBee modules (non-Pro), one RS-232 adapter and one USB adapter. Also has software you can use to play with the modules. I started with this kit and found it useful in evaluating the modules. The RS-232 adapter includes a 9v battery plug and has LEDs to show signal strength so you can use it as a portable signal strength meter (assuming you are sending data from the USB adapter). Since my application was automation control, I actually ended up using the USB adapter as my server interface which saved me development of that particular component.
Yep, did that too! I’ve moved from '2313 (replaced by
ATtiny-something) to a Mega168, and later found that the
same IC in 8k size is used in Arduino. (Great resources).
Yep-- the next version of my board uses a TQFP-32 Mega48/88/168. I like the 2313 because its small and comes in an SOIC-20 which is not that difficult to hand solder. The TQFP should be interesting.
I have been attempting to learn AVR with Studio 4, with no success. I’m better off with basic stamp. I can easily run out of space in the Stamp 1, the stamp 2 family has a bit more space.
Especially for your prototyping, choose a microcontroller solution with lots of space. I actually burned a significant amount of code on debugging support. Also, since the modules are two-way, its cool to be able to query different attributes of your hardware. But again, it all takes code space.