I’ve ordered an ultrasonic rangefinder, which will look sort of Wall-E-ish. It should fit into the same “face”, but if not, it’ll be easy to make a new one.

Robot right view

Robot left view

Robot center view

And here’s a movie. Click the image to play it.

My plan is to put some thermal motion detectors on it and go towards the motion.

At the moment it just goes in squares. Forwards for a second and a half, then counter-rotate the wheels to make a rough 90-degree turn. Repeat.

Obviously, loose wires will need to be fastened, or cats will chew on them.

Robot right view

Front view

Robot left view

I was rather hoping for an ideal Android tablet to come out with a screen size around 7 inches and that had phone functionality. (The size of the phone doesn’t matter as much when you carry a bag and have a headset.)

I was hoping that the Dell Streak at 5″ or its announced sibling, the Looking Glass at 7″ would be the solution, but it seems that Dell has crapped up Android in ways that I don’t care for.

Since I’m a developer, I want both an iPhone type device and an Android device in the house, and I had pretty much decided that it would either be an iPhone 4 and some as yet unreleased Android tablet, or an Android phone and an iPad.

I just tried the Samsung Captivate from AT&T, a Galaxy-S phone. (I’m rather locked to AT&T because of family plans. I hate Sprint and would not use it if it were the only cell carrier in North America. I have no anger towards Verizon or T-Mobile, though. I might switch if it weren’t for carrying my mother’s phone on my plan.)

I really like the Captivate, and I’m sure I’d like its siblings at the other carriers, too. Unless I change my mind in the next month or so, I’m going with a Captivate for my phone and an iPad, probably without a data plan. (When traveling, I can use my GF’s wifi hotspot. She has a CradlePoint.)

Now, thanks to the Arduino platform I can do it with a minimum of soldering!

Behold:

Thermostat project

And some detail on the LCD:

LCD Detail

At the moment, it just tells the temperature. The tiny pushbutton on the right of the breadboard turns on the backlight for the LCD. It stays lit for 10 seconds after you release the button. The little snaky-wired thing at the top-right is a thermistor, which has a resistance that varies based on the temperature. The processor detects this and uses the Steinhart–Hart equation to determine the temperature.

I also have a running clock, which will be necessary to figure out when to change the temperature when I actually attach this as a thermostat.

It’s a bit different programming a processor this simple from my usual work. This system has no operating system, 32KB of system memory, and runs at 16MHz. My development laptop, on the other hand, has 4GB of system memory and runs at 2.5GHz with two processor cores. It runs an advanced operating system.

But I’ve spent about $70 on the parts, so it’s not terribly expensive. And it’s kind of fun!

But no garbage collection on the iPhone? This is 2010! You’ve got to be kidding me!

“Hiya developers, hiya, hiya, hiya. We’ve got this device with seriously limited memory, so we’re going to force you to manually manage the memory on it. If you mess up, your app will bog the device down and probably eventually cause it to restart. Ya got a problem with that?”

Well, yes, now that you ask, I do.

I am not of the opinion that any computer language is perfect, or that any framework is perfect. But Java, in my opinion, comes close. I’m not endorsing any particular framework, and the standard Java API has its issues, but it threads a nice balance between usefulness and simplicity.

There are features such as the multitasking that are advertised not to work on the 3G, but everything that’s supposed to work works. (Are wallpapers supposed to work on the 3G? They don’t.)

I’m particularly impressed with the email client. It now has a unified Inbox, so incoming mail from all of your accounts is aggregated into a virtual folder and presented to you as one. You can still see each Inbox individually if you desire. Also, we finally have threaded messages.

Unfortunately, they’re not using the In-reply-to header, but rather by matching subject lines. This method is common, but rather stupid, since any messages with subjects like “Re: Tonight” will be threaded, even when they are completely separate messages about scheduling, possibly separated by months or years in the Inbox. Mac Mail on OS X also uses the subject line, which is stupid, in my not so humble opinion.

But it’s still a great feature. I’ve been missing it.

The other big user-visible change is folders for apps. You can now group apps into folders on your screen. Pressing the folder brings up a list of the apps in the folder, allowing you to select one. Pressing the Home button or pressing off of the list of apps returns you to the screen you were on. They can’t be nested, but who’d want to do that on a phone?

I haven’t tried tethering, because it changes my contract with AT&T, and I don’t really need it at this point.

So far as I can tell, connecting a Bluetooth keyboard does not work on the 3G.

Faces and places in the photo app and photo pickers works great! It imports the faces from iPhoto on my Mac just fine.

And creating playlists in the iPod app works fine.

All in all, this is a good update to the operating system. If I were using a 3GS I might just stick with it. Since my phone will be two years old this fall, I have been considering a new phone.

I’m still dithering between a simple phone with network-based tethering plus an internet tablet with just WiFi vs a new iPhone. If I go the former route I’m dithering between an iPad and an as yet unreleased 7″ Android tablet.

I found the DTerm app and it’s great! Basically, you just press Cmd-Shift-Enter and a command line window pops up with the directory set to the directory of whatever window was on top. So if you’re editing a file in Eclipse, the DTerm window comes up in the directory containing that file. You can do your git command and get the results, then just press Escape and the window goes away. It remembers the last several commands and their results.

Pretty clever!