thank you for reading. I need help. I have an idea for a gps tracking device that would be used for a game similar to Paintball called [Airsoft I was wondering if it would be possible to create a small device that would broadcast a gps coordinate and some sort of id number that could be picked up by a base station (laptop) and mapped in real time. Hopefully it would be run on Normal batteries (9v, AA, AAA), have a range of about 2mile max and be able to track up to 100 units (or more). Can someone help me design this device and get a price per unit estimation. I have very little electronics knowledge but if this was feasible I would go and learn. Thanks again.](Airsoft - Wikipedia)
Yes, it’s feasible, but it’s going to be very difficult or expensive (likely both). You could either use a GM862/3 GPS module as the tracking device and a GSM modem on your laptop for ‘infinite’ range (over the cellular network), or use a generic GPS module with a radio transmitter, and a receiver connected to your laptop.
I’m guessing you want to track all the Airsoft players in real-time within the combat area. The most elegant solution I can think of is a miniature GPS connected to an XBee Pro Series 2 module in mesh configuration. That way, as long as each player is within 1 mile of each other, and there is a player within 1 mile of the base station, you can get communication throughout all the modules (could allow for some neat proximity warnings, etc).
That said, to do this would be very very difficult with limited electronics knowledge, and would end up costing about $100 per unit (so 100 units will set you back 10 grand). My advice: if you’re a hobbyist, hit the books, and if you run an Airsoft company and own a combat zone (and have money to spend), hire an engineer to do the dirty work 
Will.
I think the best way to go would be something like this:
GPS: EB-85, or even better, LS20033 (not sold at SFE, but about $35 plus shipping from the maker where I get mine in bulk)
Wireless: Zigbee or Meshnetics modules. You can get a 2.4 Meshnetic module that will get you 4km open air range for around $35.
With using a zigbee stack you could create a mesh network, which means all the devices communicate with each other. Sort of like each device being a repeater in itself. Meaning you could place 100 devices in a straight line 4km apart and each one would be able to talk with each other device.
So for this application, if someone is in a hole or behind something, and another person is in a tree or on a hill, they would use that device to get back the the base station.
Controller: I would use an AVR, probably an ATMega16 or ATMega168
For simplicity you could use one of the small Arduino board SFE offers, these run at about $20ea, or $16 in quantity.
Power: I would go with a LiPo. The small 2000mAH style pack SFE offers would be fine for a 3.3v system and give you a run time of possibly 20+ hours
For the LiPo you will need a circuit to protect over/under charging, SFE has boards for this.
You could use standard AA cells, but a LiPo would be a much neater solution.
As you said 100 devices, the units become alot cheaper than making one off’s. I think your cost would be around $100 per unit, so like Will said, do you have $10,000 to spend on this?
All up, I don’t think this project would be overly complex, and if you made/assembled your own boards rather than using SFE “modules” (no offense SFE), you could get a unit working for under $100 and small enough to fit in the palm of your hand. Maybe even half the size of a credit card in LxW.
Are you just doing this for fun, or are you an Airsoft business looking to set this up?[/b]
Thanks for the responses. this was supposed to be just for fun but now that I’ve spent some time thinking about it , It might be useful for other applications(terrain mapping perhaps) so if i can get some group to latch on to the idea i might be able to get funding. but for now just a few questions what kind of accuracy would this system have geographic and altitude? what if i wanted to run 2 systems in the same area but not have them interfere or show up on the “other Teams” map?
Thank to those feel free to read and help. Here I like to ask about how to build GPS track device which can track and display data on laptop in infinite range. can anyone help me specific or give the information about device or component I should used. or design me the system which enough information.
I looking for the system operate in normal battery, can display map to find current position of device was track on the laptop and with widest range or infinite range… :?
Thanks,
The Meshnetics modules have an AVR on them that can run user code (in addition to the Zigbee or other networking code), so you could knock your BOM down by one chip that way.
There are some other low-cost meshing systems out there, some based on (eg) the Nordic chips.
If you’re interested in what other people are doing in this field check out “wireless sensor networks” and “mote” networks.
Take a look at APRS, maybe?ewerebellatok:
Thank to those feel free to read and help. Here I like to ask about how to build GPS track device which can track and display data on laptop in infinite range.
ewerebellatok:
Thank to those feel free to read and help. Here I like to ask about how to build GPS track device which can track and display data on laptop in infinite range. can anyone help me specific or give the information about device or component I should used. or design me the system which enough information.I looking for the system operate in normal battery, can display map to find current position of device was track on the laptop and with widest range or infinite range… :?
Thanks,
You want the GM862 or GM863. SFE sells them.
Coyote47:
but for now just a few questions what kind of accuracy would this system have geographic and altitude? what if i wanted to run 2 systems in the same area but not have them interfere or show up on the “other Teams” map?
The accuracy you get is entirely dependant on the GPS module you choose - but most offer a standard 5m (3.3m with WAAS) RMS error (so, let’s say accurate to within 3-4m). Altitude is apparently less accurate, with figures of around 20m of RMS error.
As for the teams in the same area, it depends entirely on how you program it. If you have one base-station for each team, they could all be part of the mesh yet only receive position signals from transmitters on that team. If you’re an ace programmer and everyone has GPS phones, you could even program in a FPS-style local map on each person’s phone with friendlies and terrain shown There won’t be any interference between transmitters if you use 2.4GHz radio modules (GPS transmits around 1.5GHz).
Gussy, nice call on the Meshnetics modules - I’d never even heard of them, but with built-in AVR they’re perfect for a whole bunch of projects I’ve thought up in the past. I agree with the hardware design as being fairly simple (but then again I’m an electronics engineer), but it’s the wireless protocols and mesh integration, as well as the host software for the PC that will be the difficult part, requiring knowledge about a whole lot more than just electronics. I’d also go with disposable batteries to keep costs down.
Will.
That fps map idea sounds amazing. what do you mean about the wireless protocols and mesh integration being the hard part? this project sounds like alot of fun. but first i need to know what i’m doing. what books would you guys recommend?
I’m not such a big fan of books for learning for projects like this, I would rather learn hands on.
If I were you, I would go and buy some parts like Meshnetics modules, GPS modules and just start playing using examples found on the net. Probably start with enough bits to make 2 or 3 “devices” to keep the costs down.
Another thing that helps a lot is to read datasheets for the parts your using.
What Krogoth means is that the software part is going to be hard, not the hardware part. The actual electronics of this is simple, its just connecting a GPS serial port to a microcontroller then to a RF module.
I suggest to try the Arduino offerings SFE has, there are loads of examples and help on the net for them.
Basically 10% or less of this project is hardware. The other 90% is software.
never mind either GM862 or GM863,.
unless I can used to track in high wide range, that what i want…
TQ.
to you, which one is better, have u know what gps model with radio transmitter and receiver
what amount of software has to be programed on the Device? once i’ve got the data on to the computer I know how to do that programing. but what kind of programing will be needed for the devices? also what kind of radio reciever will i need for the laptop?
Coyote47:
thank you for reading. I need help. I have an idea for a gps tracking device that would be used for a game similar to Paintball called [Airsoft I was wondering if it would be possible to create a small device that would broadcast a gps coordinate and some sort of id number that could be picked up by a base station (laptop) and mapped in real time. Hopefully it would be run on Normal batteries (9v, AA, AAA), have a range of about 2mile max and be able to track up to 100 units (or more). Can someone help me design this device and get a price per unit estimation. I have very little electronics knowledge but if this was feasible I would go and learn. Thanks again.[/quote]Rather expensive in cost and battery. But if you can stand $100ea and a fairly large battery with, say, 8 hrs between recharges, it can be done. For 2mi you may well have to use public carrier cellular data, unless you have clear line of sight and can use high power at 900MHz unlicensed. For that 2mi case, look at these rather expensive modules that take a lot of battery:
http://www.digi.com/products/wireless/z … sh-900.jsp
(900MHz is North America only).
The 2.4GHz XBee et al, even with the PRO at 60mW, is not a good fit here due to the propagation problems, esp. with non-line-of-sight and the fact that even no-gain antennas for this have nulls.
A good GPS is SiRF-III, $59, integrated into many products; maybe here on SFE, and I have one from Tyco via Mouser. You have to program it using a special protcol to do sleeping to conserve power. I also use a vibration sensor (<$1) to influence sleeping. GPS is the largest battery consuming element. An Atmel AVR -P series micro is a good low power micro. (people tracking via GPS is done in military training systems, I know from job experience).](Airsoft - Wikipedia)
Coyote47:
what amount of software has to be programed on the Device? once i’ve got the data on to the computer I know how to do that programing. but what kind of programing will be needed for the devices? also what kind of radio reciever will i need for the laptop?
Second question first, that one is easy. The receiver would just be one of the RF modules hooked up to USB of the laptop. The RF Modules (like the meshnetic ones) are transmitters and receivers so you don’t need anything special on the receiving end. Only difference is it has a USB output, maybe in a nice box and probably a bigger antenna.
As for software, if it were just a case of point to point comms, it would be a simple program that received the GPS data, maybe added some info like unit ID, battery voltage, and then sent it on the the RF module. Pretty simple stuff. You could add other things like GPS fix lights, status lights but that’s all cosmetic.
I have not played with the Meshnetics module so I don’t know how easy it is to get them to form a mesh network, but thats all you need to do, and that would be the “complex” part of the code. Although I doubt you would have to write it all yourself, I think the idea of Meshnetics is that they provide meshing code/functions for you to use.
A quote from the Meshnetics website: “802.15.4 / ZigBee stack featuring self-organizing, self-healing mesh network”. So you may not have to code any meshing software at all, it may just be a case of telling the module on setup that you want a mesh network. That would make the code VERY easy, maybe only 50 or so lines for GPS receiving and forwarding.
If your patient, got a bit of time a $$$ to spend, this wouldn’t be an overly difficult project.
I have to say, if implemented right in a “high tech” paintball/airsoft situation this could be VERY cool. With a 5Hz GPS you would see smooth and realtime positions of players, and the “captain” of the team could have a handheld reading unit which showed where all his players were.
If you really wanted to get into it, you could sense with a microphone or switch when the players gun fires, and then that would show up on the oppositions map for 5 seconds, just like in the real FPS games.
If you get something working well you could try pitching it to large paintball/airsoft operations.
stevech:
Rather expensive in cost and battery. But if you can stand $100ea and a fairly large battery with, say, 8 hrs between recharges, it can be done. For 2mi you may well have to use public carrier cellular data, unless you have clear line of sight and can use high power at 900MHz unlicensed. For that 2mi case, look at these rather expensive modules that take a lot of battery:http://www.digi.com/products/wireless/z … sh-900.jsp
(900MHz is North America only).
The 2.4GHz XBee et al, even with the PRO at 60mW, is not a good fit here due to the propagation problems, esp. with non-line-of-sight and the fact that even no-gain antennas for this have nulls.
A good GPS is SiRF-III, $59, integrated into many products; maybe here on SFE, and I have one from Tyco via Mouser. You have to program it using a special protcol to do sleeping to conserve power. I also use a vibration sensor (<$1) to influence sleeping. GPS is the largest battery consuming element. An Atmel AVR -P series micro is a good low power micro. (people tracking via GPS is done in military training systems, I know from job experience).
I would go with something like this over a XBee, http://www.meshnetics.com/zigbee-modules/amp/
Provides 2.5 miles range and has an onboard AVR that can run user code.
A good GPS in quantity wouldn’t be $59, more like $25.
As for sleeping and power saving, the Meshnetic module only uses 50mA when transmitting. So if it was transmitting 100% of the time (unlikely), that would still be 40 hours on a 2000mAH LiPo. Obviously that’s optimistic, but still anything over 15 hours would be more than enough for a days use.
Regarding the power, I would go with LiPo’s like I said before because firstly the a light, they are also just as cheap as an AA and its plastic holder when you buy the LiPo in quantity from china, and also the cost of having to buy/replace AA batteries would be huge, I would much rather put some units on charge overnight than open up and replace AA’s on 100 units. I’ve done that before with GPS’s and its not fun.
Thanks guys for all the Useful info!! I’m thinking of trying this with maybe 4 or 5 units and fielding it with squads for trials and see how people like it. I’ve read through the basic tutorials on SFE and get the gist of what I’m doing now. though I wonder if there might be a data transfer problem with 50 players units all trying to report 5 times a second?
You could do the maths on it to work out the kind of bandwidth you need, but 5Hz isn’t necessary for starters. start with 1Hz maybe to get things going.
Most of the info the GPS spits out you would not need to resend. Would you even need speed/altitude? The most inportant thing would be the Lat/Long coords.
An example message you could send might be something like:
(in a NMEA, GPS output style)
$PR,ID,LAT,LONG*CHECKSUM
Where PR just stands for “Position Report”, or something similar so the base station knows that’s what it is.
You could also have something like “$LB,ID,VOLT*CHECKSUM” for when a unit gets a low battery.
As for teams, you might as well do that on the computer end, and if teams have access to the computer just make it a secured app to assign unit ID’s to teams. That way you can switch devices between teams on the fly.
Actually, you could make the sending dynamic. For example, if the person is not moving very much, send at 1Hz, or if they are moving lots, say running, send at 5Hz. That would be a easy and nifty way to reduce the bandwidth needed.