Need help with project and sources

[elsherst]

I'm new to building circuits, but have repaired and diagnosed minor problems with them for a while. Being new to building them I don't always know why or when or what is needed in the circuit.

Here is a project that i've been asked to figure out that I need some help with:
It's going to have 3 seperate parts that will need to send small amounts of data when they get close to each other. I was thinking of using bluetooth class2 for sending and receiving the data (would take suggestions here if FM or something else would work better). PartA will need to have a GPS chip in it to send the location through the bluetooth to PartB when it gets within 20ft of PartA. PartB will then send the location it received from PartA to PartC when it gets within 20ft of PartC. PartC will be hooked up to a scale and will store the location and a tag of some kind (simple number of which PartB it's getting the data from) and the weight from the scale while PartB is on it. At the end of the day it needs a way to pull all the data it has stored from that day (simple USB connection with a memory key plugged in the whole day, or some way to plug it into a computer to pull that information off it, maybe even a way to use the bluetooth to connect to another device and pull the data off, any other suggestions here would be helpfull as well)

So in summery I have:
PartA- Bluetooth with GPS possible proccessor if needed to send location
PartB- Bluetooth with small storage and possible proccessor to know when to recive location data and when to send location data
PartC- Bluetooth with some form of interface and or storage, something to trigger when to receive the data and an interface to plug into a scale to receive the weight.

I'm not sure on sources for all of the parts (like the GPS chip and antenna) I've found a lot that have resistors and boards and bluetooth and FM transmiters and recivers. But I wouldn't mind suggestions of places anyone else gets their parts from. I'm not 100% sure on if I want to have a company make the boards and have me put all the parts on it, or if I'm just going to make a PCB and put the parts on it.

Any help or suggestions would be greatly appreciated. So Thank you in advance.

Dave

 

[Mike_2545]

Have a look at this page

SparkFun Electronics - Wireless

 

[elsherst]

Thanks Mike, that's the first one I've seen that had GPS recievers.
Any suggestions on which wireless connection would be the best used at around the 20-30 foot range?

 

[Mike_2545]

The X-Bee modules are nice.

 

[elsherst]

Cheap and look easy enough, but I'm looking at multiple PartA and PartB's, I'm worried if the range on the wireless connection is big enough PartB is going to pick up the location from the wrong PartA.The parts will be about 10-20, sometimes 25 feet apart. That's when i want PartB to get the location information from PartA. Is there a way those X-Bee modules can do something with distance so programing can have triggers set to get the location when the parts are close enough together?

 

[Mike_2545]

There are lots of programming options with those modules, I have not cracked them all.

If you want individual modules to talk to each other you can probably do that easy enough through programming.

Good answers to X-bee modules can be found on their chat site.

 

[elsherst]

Do you have link to their chat site?
Any idea what type of components I would be looking at for the simple PartA unit, Looking at GPS, and XBee wireless 12V DC power input so if i'm doing the math right a 430 ohm resistor. Would I need something else to trigger the Xbee to transmit the GPS data?

 

[Mike_2545]

Here is the Sparkfun Forum link SparkFun Electronics :: Index

If the GPS data is serial then you can transmit that directly with the X-Bee units.

 

[elsherst]

Thanks Mike.
I just touch of something I had read about bluetooth and wonder if it is anything similar with the X-bee. With lower power the bluetooth won't transmit as far, if I dropped the voltage to the X-Bee would it's range be reduced but still be able to transmit good enough to send the needed data?

 

[Mike_2545]

The X-Bee units operate at 3.3v.