link and attachment of code in my previous post on: February 03, 2012, 08:08:15 PM
Oh, well I missed that -- was just looking at the body of your post.
Anyways, it's GPLv3. A better term to use would be Free Software
, as opposed to "Open Source". While many people make little to no distinction between the two, there are differences, and anything published under the GPL is "Free Software".
I advise that you read the entire license: http://www.gnu.org/copyleft/gpl.html
If the author will not accept patches, then there's little that you can do, except maintain your own fork
As far as the original author not responding to questions, that's understandable. And a small project like that won't have a support forum either, though maybe the author is on some Arduino forum, somewhere. But determining who that is will be problematic, because the .pde file doesn't do a good job of identification. I note that there is no Copyright notice, though the line at the top referencing ZeroFossilFuel might be intended as such, and the author just forgot to include the word "Copyright". You can do a whois lookup on hydrtec.com, and see it registered to someone in Great Britain, but that's not especially informative.
Did you specifically e-mail saying that you wished to submit a patch? A patchfile can be very simple: http://stephenjungels.com/jungels.net/articles/diff-patch-ten-minutes.html
-- scroll down to 'Creating patches with diff'.
If your changes result in the code being not useful in the way the original author is using it, then I'm not surprised at a patch being rejected. In this case, a fork is the only thing to do.