There are a number of ways out there for you to figure out how the cost of installation and purchase balance out with the cost of operation over time. You can always make your own Excel spreadsheet to figure it out, or you can use calculators like this one from energy.gov. However, all the web payback calculators I’ve seen have had clunky 90s interfaces, don’t take into account all the variables, and most importantly, don’t let you compare multiple types of heaters at the same time. So, like any good software developer, I built my own.

My water heater calculator is based on the same calculations used on the Federal Energy Management Program site, with the addition of inputs for your hot and cold water temperature. It’s also more flexible about how you enter your water usage. But the best part is that you can enter as many different water heaters as you want and they’ll all be graphed against each other, taking into account the lifetime of the unit. Get multiple bids, try different models, compare gas and electric. By displaying them as a graph of total cost over time, you can see where each heater breaks even with each other, and how much savings you’re getting by the end.

As a bonus, the calculator will also calculate how much you may be able to claim as part of the Energy Star Federal Tax Credit program. It’s smart enough to know the rules about the credits (gas heaters >e; 0.82 efficiency only, 30% of total cost up to $1500), and you can choose not to use the rebate if you’ve already used it up this year or don’t plan on applying it to your heater.

You can get started with the calculator by filling in values for your water usage and resource costs, or accept the defaults. Then add as many heaters as you like, entering in the cost for purchase and installation, the Energy Factor (which should be in the documentation for the heater), and the estimated lifetime of the heater. The more accurate you can make the numbers, the better your cost projection will be. Then check out the graph to see what your total expenditure will be after every year. If you’re comparing a new heater with the option of keeping your existing heater, just set the Cost to $0 and reduce the lifetime to how long you expect your existing heater to last.

Hopefully this little tool will be helpful to anyone else looking to replace their water heater. I filled it out for a combination of several electric, gas tanked, gas tankless, and heat-pump based water heaters, and it gave me a much better picture of what was worth it and what wasn’t. In the end, even though the graphs told me that the increased efficiency of a gas tankless heater wouldn’t ever pay back the cost difference versus an electric tank water heater, we ended up going with one. The promise of infinite hot water (long showers after a hike!) and no chance of burst water heaters outweighed the additional cost. But at least we were well-informed!

We decided to use the open-source Arduino microcontroller platform to drive LEDs inside the domes – that way we could have a bunch of independently-controlled lights and set their behavior with software. We chose the Boarduino Arduino clone from Adafruit Industries because it’s cheap, easy to assemble, and much smaller than the full-size Arduinos. Soldering it together only took an hour or so.

After that we connected a total of 11 superbright LEDs (ordered from DigiKey) to the Boarduino. Since the Boarduino only has 6 PWM pins (which can be used to “fade” LEDs in and out), we put 5 really bright LEDs on their own PWM pins (for the big domes) and wired the remaining LEDs (slightly less blindingly bright ones) in parallel to the 6th pin. The LEDs are unbelievably bright – even after covering them in an anti-static bag they are tough to look at directly.

At this point we had to sketch up some software to actually control the lights. Eva wanted a random, organic pulsing, so I started by having each light animate through 360 degrees and used trigonometric functions to create a smooth curve of lighting and fading. We tried a whole bunch of different speeds, patterns, brightnesses, and randomization (some different tests: 1 2 3 4) before settling on the final code. The code is a bit messy because of all the things that got changed around. I ended up using 1 – abs(sin(θ)) as the main brightness function, which gave the lights a sort of “breathing” effect.

The 0-1 values from that function got converted into a brightness from 0-255 for the PWM output. Actually, the brightnesses were always between a set minimum and maximum brightness, so they never quite go all the way out. Each cycle the speed of the fade gets randomly modified, so the lights never line up in any pattern – it’s pretty hypnotic to stare at.

After this Eva had the unenviable task of stuffing the whole works into the beast. She built little foam stoppers for each LED, and pushed one up into each dome. Then she carefully crammed all the wires inside, and the Boarduino, a switch, and the 9V battery. It ended up being way too cramped, resulting in a lot of broken wires, resoldering, and hot glue burns. Lesson learned – the next glowing beast will be bigger, with more open access to the inside.

The end result is really captivating. Eva ended up displaying it at Gallery Madeira in Tacoma, WA along with some of her other creatures. Since we both put a lot of personal attention the two of us put into the Glowback, and the fact that due to all the hairy wiring inside it’s sort of “high maintenance”, we decided to keep it for ourselves instead of offering it for sale. However, Eva’s not done with the idea of lit beasts containing microcontrollers.

Eva’s has written up a post on the Glowback from her perspective on her own blog – I suggest checking it out to get more detail on the concept and lineage of the piece.

I didn’t even use the nubbin, I just used its button. However, on my new ThinkPad, the center button switched the nubbin to scrolling mode, and turning that off in the driver just made the button do nothing! However, I recently stumbled upon the solution. If you completely uninstall the UltraNav driver, the middle button becomes a normal middle mouse button again, and the nubbin and trackpad still work. Tab management is easy again!

The second major purpose for my blog is as a place for me to record the solution to problems I run across while developing software, so that others won’t have to spend hours Googling or using trial and error to come to the same conclusion. I didn’t intend to rehash things that were easily found or that had already been discussed – only to post when I felt it was something that added value to the internet that hadn’t been there before. So a lot of the blog posts are not really a narrative or running commentary – they’re not meant to be subscribed to, but found individually. It’s for this reason that my most popular posts tend to include the exact text of error messages. This type of post has suffered both because I haven’t been doing as much development, because I can’t discuss a lot of what I’ve learned due to the nature of the projects I’m working on, and because I’ve been learning new stuff (like Ruby on Rails) and haven’t done enough to have solved problems others haven’t already posted solutions for.

The third reason I have this blog is to occasionally talk about my thoughts on different technical topics, from web development to video games. Again, I don’t like to make a post unless I think I’m adding something new, and most of the topics I’ve wanted to talk about have already been covered. I had a lot of draft posts sitting around about web development, web standards, and the evolution of browsers, but then I discovered Alex Russell’s blog and it turns out he’s already said most of what I wanted to say, and better than I could. Other stuff, like my impressions of Windows Vista, critique of stackoverflow.com and suggestions for the Xbox Live Arcade lineup, have been covered to my satisfaction in plenty of places. Maybe some of them will end up posted, but probably not.

Another part of the reason I haven’t posted much is the sheer weight of unfinished posts I have. Right now I have 64 drafts and only 52 real posts! So I’m going to attempt to clear things out by writing a little about what I haven’t posted. A lot of this stuff wasn’t posted because it fell under that third point above, but some of it I was just too lazy to flesh out into real posts. Some of it’s just random stuff. So here’s what’s been happening in the last year:

I got on the bandwagon and picked up iPhone 3Gs for myself and my wife. Everything good you’ve heard about the iPhone is true. Also, almost everything bad you’ve heard about them is true. I really like the device, the UI, and the web browsing, and now that the NDA over the SDK is gone, I might even try to write an app if I get an idea.

I built a new computer in March of ’07 to replace the machine I had built for college. The new machine is set up as a developer machine primarily, with the additional goal of being as quiet as possible. I can’t say I’m entirely happy with it, since I’ve had some trouble with the hardware and overheating issues mean I have to run the fans above “totally silent” mode. It does its job well enough but I might just buy a Dell next time. The huge CPU heatsink I used is awesome, though.

I’ve been running Windows Vista x64 since my new machine came online. While I think it’s a disappointing release given the 5-year gap between it and Windows XP, I generally like it. It’s certainly better than Windows XP and I wouldn’t go back. I’ve hit some trouble related to using x64, but overall it’s pleasant.

Before that, I was getting pretty sick of the aging Windows XP, so I bought a Mac Mini and ran it, using OS X 10.4, on a second screen next to my XP machine, joined via Synergy. I liked it a lot, but never moved much of my work over there. After getting set up with Windows Vista, the difference between OS X and Windows wasn’t so great, and I unplugged the Mac so I could have both screens for Windows. I moved the Mini up to my TV and used it with Front Row as a media center. Then the Xbox 360 got the ability to play DivX videos, so I stopped using it for that and brought it back downstairs. I was using it for browser testing, but then Apple released a Windows version of Safari. Now it mostly stays off, except when I want to use Handbrake (which won’t work on Vista x64). I still like it, and I really miss having an OS with a real command line, especially now that I’m doing Rails stuff and spelunking through a lot of badly-documented libraries. I’m not sure I’ll ever make the switch though. That said, my trusty old Thinkpad finally died last week, and if I can’t revive it I might look towards the rumored lower-priced MacBooks that should come out soon.

I got two awesome cats named Ozette and Skagit. A lot of my time at home just involves relaxing and petting the cats these days.

After years of using Thunderbird, I switched to GMail as my main mail client so I could use it from the web and use IMAP on my iPhone. I set it up to read all my old POP mailboxes, and I use Google Chrome’s application mode (I used to use Mozilla Prism) to make it look like a standalone app on my desktop. It’s an OK mail reader, especially since I get a lot less email to my personal accounts these days. The main annoyance is spam – I used to use POPFile to filter spam, and it was perfect, with almost no false positives. In contrast, I get maybe 50 pieces of spam leaking through on GMail a week.

Spam has not been limited to my inbox: my support forums are basically nothing but spam and people complaining about stuff I’ve given them for free. It takes a lot of maintenance, and I’m thinking of either trying to transition them to something less attractive to spammers, or just shutting them down entirely.

Back when IE7 was in beta I wrote a handful of bug repro’s for problems I found with it. Recently I’ve been running across all kinds of crazy things in both Firefox and IE, so I’ve been cataloguing them with little examples. Most of them have been fixed with the latest release of each browser, but I figure they’re still useful if anybody’s seeing those problems happen.

I went to Southeast Asia for two and a half weeks. We toured Vietnam, Cambodia and Thailand. It was incredible.

I finally got so sick of CSS that I decided to write a processor that would take an “evolved” CSS syntax that supported named constants, nested selectors, arithmetic, mixins, and such and spit out real CSS. I had it all sketched out and was ready to start implementing when I found SASS, from the same guy who awesome-ified HTML with HAML. SASS is feature-by-feature the exact same thing I wanted to do (except for the whitespace-significant thing, but I can deal). I love it.

I’ve been pretty disillusioned with ASP.NET as a web platform – the web forms are too inflexible and unfriendly to clean markup and unobtrusive JavaScript, and C# feels too rigid and verbose for what I’m doing. LINQ and the other 3.5 features help a lot, but my host is stuck on 2.0. I still haven’t found any templating system that trumps Web Forms, which is why I’m still stuck on Windows hosting for the most part – a lot of my sites are built on ASP.NET for nothing more than the templating. While I’m keeping my eye on ASP.NET MVC, I’m more interested in cross-platform web technologies that give me a bit more choice in hosting.

To that effect, I’ve started a personal project on Ruby on Rails, mostly to learn the platform. So far I’ve really been liking it – having a functional, dynamic language is great, and the structure Rails gives you really helps to quickly get things running. Hopefully I’ll be able to show what I’m making at some point, assuming it works to my satisfaction.

I actually went through a big comparison of different web platforms and different languages, trying to gauge what would be the best for me to develop for. I’m not sure I’ll ever publish my full results, but Ruby on Rails was obviously up there, and Django / Python looked good too.

Speaking of languages, before I discovered jQuery I didn’t really do much JavaScript if I could avoid it. Now I’m writing tons of JavaScript to produce some really nice interactive web apps. I have never been as impressed with a library or platform as I have been with jQuery.

I’ve actually been using Eclipse a lot lately, both for Aptana and for straight Java development, and while it’s slower and buggier than Visual Studio, a free copy of Eclipse plus all the free plugins make it much more compelling than the Visual Studio Express products I use for C# work. Stuff like the outline view, refactoring support, quick fix mode, and real unit testing and source control plugins make all the difference.

I think that’s about all I wanted to get off my chest for now. Hopefully I’ll have a chance to flesh some of that out into full posts sometime, but at least I won’t have so many unwritten drafts staring at me every time I log in to WordPress.

The other site, which just launched, is my wife’s new art site. She makes wood-fired ceramic sculptures of bizarre, cute creatures, and the new site was hand-drawn by her to reflect their style. It’s implemented as a WordPress theme, which gives her a much easier way to manage the content of the site, and it also means that she can now blog about her process and other art topics. Check out some of the cool time-lapse videos of her sculpting the critters.

Anyway, that’s what I’ve been up to. Hopefully soon I’ll be able to get back to building more cool things and talking about them, as well as clearing out my backlog of draft blog posts.