Hooking up an electric car to transmit battery current wirelessly to a laptop

NOTE: I have never used an arduino or anything like the setup I have a question about. A standard Computer motherboard is as far as I've ever been in electronics and this appears to be a whole different realm of electronics.

My College class is requesting a setup of an electric car that calls for wirelessly transmitting information from the vehicle to a laptop in "the pit". I believe the setup should be as follows:

12V car battery -> Hall-Effect Current Sensor (ACS721) -> Arduino -> Xbee wireless chip mounted on an Xbee Shield -> (WIRELESS TRANSMISSION) -> Xbee wireless chip with a cable converting to USB -> Laptop

The sending and receiving of information needs to be managed or setup or something with Digi's X-CTU software and I believe we have to write a C++ program to manage the data as well. My problem is how exactly do I wire and setup up all these parts? I am the only person working on this entire setup and I do not know much about electronics or Xbee communication and the transfer of data. Most specifically, I would like to know how to wire and use the Hall-Effect Current Sensor with the arduino board and how to view that electrical current data on my laptop.

I am VERY familiar with computers, (which is why I was drafted for this :/) and the C++/Computer portions of this project but that does not mean I am familiar with all these Electronics.

For the current sensing, you need to find a Hall Effect current sensor with sufficient current range and a built in amplifier, this would give you an analogue output which you can read via the Arduino's analogue ports. Do you know what sort of range you're expecting to need? Some of these wireless solutions are quite limited in range especially when in an electrically noisy environment, so consider this when you design the radio side. There are plenty of examples showing how to send data from an Arduino via Xbee so that side should be easy enough. You'd need to provide an application to receive/log/display the data too, of course.

What kind of application can I use to view the data? And we are planning to have two 12V car batterys with the hall effect sensor

I would recommend you start with a current sensor and arduino connected to the pc via usb. Tackle that, then do the wireless part.. Check sparkfun for current sensor or they sell some cheap ones on aliexpress at least (bought one, but not tested yet).

Unless you're planning to just plot the data in excel or something you'd probably have to write some app to display the data yourself..

Things will probably be a lot clearer once you've gotten the basics :)

The problem is we have to order ALL of the parts at one time, so I can tackle things one at a time, but I need to know exactly everything I will need beforehand. The BIGGEST problem right now is what I will need to get for the Hall-Effect Current Sensor to properly connect it to the arduino (including wires and such I need for the board itself).

CTE_T: The problem is we have to order ALL of the parts at one time

In that case there's a significant risk that you will order the wrong stuff, or forget bits that you need, or buy stuff and then find that the project has to be scrapped or taken in a completely different direction.

I think you should treat this as a research project, not a construction project. You're going to make mistakes, try things that don't work, blow stuff up, and hopefully eventually figure out how to do it. But if you only have one chance to buy hardware, you're either going to buy stuff you don't need or come up short later on.

CTE_T: The problem is we have to order ALL of the parts at one time, so I can tackle things one at a time, but I need to know exactly everything I will need beforehand.

Well, good luck, but like Peter says it's unlikely you'll be able to order everything right the first time, nor do I see why any project would need you to order everything at once... At any rate, minimum if you're going with the xbee route would probably be:

2 * xbee 2 * arduino (with usb cables) cables (you know what cables you want/need?) - might only need for connecting the xbees and powering arduino on the RV side, on the other hand you get lot's of cheap cables for $5-10 soldering stuff (iron, wick, solder, flux) current sensor mounting?

As a programmer you should know that you should start with the basics or prototyping and test stuff out when you don't know anything about it. And electronics isn't like programming, if something doesn't fit quite right or missing some part you can't just change some lines and it's okay..

Also remember that the current sensor needs to intercept the entire battery circuit.. And is xbee what you want? You want to try other technologies? I've ordered some nrf24l01+, also not tested, but cheaper.. Resistors, inductors, capacitors, diodes needed anywhere?

Wow this is stressful. So ordering parts individually and testing things out is how you would approach this project?

Id say go with the nrf24l01+, 4$ ea on ebay and its well qualified for something like this, I’ve never used an xbee mainly because of the price, id rather have a barebones atmega328 and nrf24l01 so that that one side costs 10$, then just receive with my uno and transmit to pc
also how will the devices be powered, from the batteries I assume?
And I gotta agree with the impossibility of buying everything you need at once, I usually buy what I think I need with extra to put aside, then when I need some arbitrary piece I have it from extra from a previous project

CTE_T: Wow this is stressful. So ordering parts individually and testing things out is how you would approach this project?

Depends how difficult it is to place an individual order. If it is especially difficult to buy/ship stuff where you are, it might make sense to buy more stuff at once and risk getting stuff you didn't need. But the idea that you can plan it all in advance and expect to get it right, is extremely optimistic. Usually I would defer buying anything expensive or difficult to get until I knew it was what I wanted and that the project would definitely need it. But if the difficulty/expense of splitting shipments up outweighed that, then throwing your money at it up front might be the right answer.

Alright so, taking this project as a research and study project, this is the set-up I want to do:

Car Battery Circuit (2 Batteries, one in, one out [This isn't my part of the project]) -> I believe positive and negative are then wired to this- http://www.sparkfun.com/products/8882 - hall effect current sensor. Then I need information on how to attach this model to an arduino or http://ruggedcircuits.com/html/ruggeduino.html. After that is attached, I think I need to write a C++ program using arduino in order to instruct the board to send the current settings to Xbee. I also need to figure out how to embed my xbee chip and shield (http://www.trossenrobotics.com/store/p/6367-XBee-Shield-V1-1.aspx) in/on/wired to the arduino. Then I have an Xbee-to-USB converter to plug into my laptop and have to figure out how to get the information on the laptop using Digi's XCTU utility and some other missing piece of information vital to receiving the data.

I found this tutorial series: http://www.youtube.com/watch?v=fCxzA9_kg6s&feature=relmfu

Hopefully it will help me understand the arduino.