An easy-to-use code flow diagramming tool?

In the day I took out a desk size pad of paper, a couple of pencils and an erasor in preparation of making a flow diagram of my code. This is 2012 - the 21st century. What is a good tool (preferably freebe) that allows me to do this job on my PC?
Ken

Few people flowchart these days.
You could try Visio

http://www.picaxe.com/Teaching/Logicator-Flowcharting-Software/

I'm talking Arduino Nano C-Code.

I am trying to get a USA public high school teacher and students involved with the code that drives my robotic 1/10 scale radio control car.

See:
Arduino based autonomous radio control model car
http://arduino.cc/forum/index.php/topic,84400.0.html

Reading the code would be much easier with a code flow diagram to reference. My computer does not have VISIO. Logicator seems too specific. I'll give Dia a shot....

Thanks, Ken

Here is another alternative: yEd - yEd - Graph Editor - free and works on all pc platforms.

I've down loaded DIA and Yed. I'm not finding the TASK BAR instructions easy to understand. Can you point me to some examples on the WEB?

Here is a short video tutorial yEd - Graph Editor
and the manual yEd Graph Editor Manual | yEd

Was lurking...

I downloaded both packages for the Mac and gave them a quick try. For flowcharting (only) yEd looks pretty good - and for flowcharting plus a lot of other flavors of diagramming, Dia looks like a winner (although it uses up a sizable amount of file space).

I decided that for the time being I'd keep yEd for flowcharts, and see how much I actually need the capabilities of Dia. If it turns out that I don't need all that capability, I'll un-install Dia.

I think I'll retire my old green plastic template. :grin:

yEd seems easy enough, but.....

Does anyone know of an example of a yEd C-code flow diagram? I am not doing well figuring out how to take the flow out (off the page-maybe) to a subroutine or a function.

Represent the function call with a "pre-defined process" flowchart symbol.

You can flowchart the called function just like any other program.

Ken - Sample attached (It'd have been better if I could have figured out how to label the decision choices. :grin:)