Voltage Measurements and Graphs

I know I seem like I'm trying to find an easy way out here, but I truly just need a tiny bit of guidance on where to start. I've done Java and JavaScript, but I have no experience whatsoever with Arduino. My plan is to try to watch videos and find DIYs online, but I just want to make sure I'm going in the right direction.

What I want to do is use the Arduino as a voltmeter and record these voltage values over a certain period of time, then be able to output these voltages over time into graphs on my computer. I also want to include an LED alert of sorts for when either the voltage or the current reaches zero, since I'm measuring a primary cell (it's actually for a high school science project). I hope I can figure this out and thank you guys for your help!

This is doable.
You can send Arduino data to the computer in CSV format then graph it with Excel.
Use a program like Realterm to receive the data and store it to a file.
http://realterm.sourceforge.net/

You can also use other software like MegunoLink to get the data and print it to a graph all in one.

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Once you have the data (saved to an SD card perhaps?)… you can make a graph/visuals using many languages/apps…

(not sure about the location/placement of what you want to measure)

Processing
Excel
Flash
JS/jQuery

etc…etc.

Silly notion.

The original intention of the Processing language and IDE... (the basis for Ardiuno) was for data visualization. The Processing option is a viable method to achieve what you want as well.

Have a look here:

RealtimePlotter

I use the serial functions of matlab to read in data and graph it in real time.

I bet there is something in java that can do that as well.

That way you leverage your java knowledge.