Category: Revelation

Airplane Prop + CMOS Rolling Shutter = WTF

Check out this utterly awesome picture taken of a Yak aerobatic trainer taken with a iPhone:

Airplane Prop + CMOS Rolling Shutter = WTF on Flickr – Photo Sharing!.

The combination of the slow scan speed of the camera and the movement of the prop has done something fascinating to the image. In the old days, some cameras had moving slits for shutters and they did similar effects to propellors, but usually the props just looked a little bent, rather than discombobulated.

iPhone Logbook App requirements

Ok, so what do I want from an iPhone App? How about I list the requirements as I see them, and order them from highest to lowest? I have an idea that I can then choose a bunch at the top of the list and say “this will be the first release”, then a bunch below that to say “this will be the next release”, and so on down the list.

The perfect iPhone logbook app:

  • Must not require an internet connection!
  • User must be able to enter a new flight.
  • User must be able to browse existing flights.
  • User must be able to total up existing flights
  • A flight consists of a brief description, a series of one or more locations, the aircraft that was taken, and the number of hours spent in certain activities such as “Pilot in Command”, “Cross Country”, “Dual Instruction” as well as counts of other non-timed activities like “Day Landings” or “Precision Approaches”.
  • A particular aircraft should be known by its capabilities so that the user can get totals of time spent in those capabilities, such as single engine or multi engine, land plane or sea plane, complex, high performance, turbo prop, jet, etc.
  • User should be able to filter on date ranges, capabilities, aircraft flown, activities logged, etc, in both the browse and total functions, so, for example, you can total up how many flights you took where you made a night landing in a complex aircraft while pilot in command, or see all the flights where you landed in Syracuse (KSYR).
  • User should be given warnings of “currency” items, based either on recently logged flights, like if you’ve gone 90 days without 3 day or night landings, of for calendar items like when your medical expires.
  • User could track other things in the flight, such as who else flew with you or flight number that would be filter-able
  • User could have an unstructured note field to note down other facts about the flight that are not filter-able.
  • User could export the flight log to a Google Docs spreadsheet. (Some other iPhone apps do this – I wonder if there is an API?) (Obviously an internet connection would be required during this operation)
  • User could import the flight log from a Google Docs spreadsheet. (I have no idea if that’s even possible!)
  • User could customize the duration and count fields for flights.
  • User could customize the rules for currency, even combining several factors.
  • Application could publish an interface so that other apps (like CoPilot, for example), could transfer information from a flight that was planned or flown into the logbook.

That should keep me busy for a while, eh? Any additions?

New Blog Category: iPhone Development

I’m going to document what I’m doing on this iPhone development project, and it’s going to be in a separate category. If you want to follow just this without following anything else, you can point your browser at https://blog.xcski.com/category/activites/geekery/iphone, and if you want to follow it on RSS, https://blog.xcski.com/category/activites/geekery/iphone/feed

Here’s what I’ve done so far, since signing up as an iPhone developer 4 days ago:

  • Watched the introductory iPhone developer videos available from the Apple Developer Connection
  • Read up to page 91 of 133 of “The Objective-C 2.0 Programming Language” (should finish soon). Decided that Objective-C is pretty weird looking, but it might have some merit. It appears like the bulk of “learning the language” isn’t going to be in the language syntax itself, but in learning the frameworks and libraries – sort of like Java, but much more so.
  • Downloaded the iPhone SDK. Fired up XCode and loaded one of the default app frameworks and ran it in the simulator. Decided that XCode is quite different from Eclipse, but if I learned to like Eclipse, I can probably learn XCode as well.
  • Started defining the requirements for the application. Haven’t decided if I’m going to do multiple posts about that, or just have one post and keep coming back to edit it.
  • Decided that I should do the design and development as openly as possible – yes, I’d love for my app to get on the App Store and make lots of money, but I think it’s probably more important to have something I can show prospective employers to prove that I’m not letting my skills atrophy just because I’m working as low man on the totem pole at a multi-layered bureaucracy instead of being top dog on a small team like I was for the last 6 years.

Next up, after finishing the Objective C document is probably to read the iPhone Application Programming Guide and maybe to work on a few small examples. And also to sketch out some ideas for the user interface. I really want something that looks good, and my past performance in that area hasn’t been the greatest. Maybe I can use that 99designs site that StackOverflow used for their icon to design an icon set?

More kayak workout videos

I won’t bore you with the whole thing. Instead I’ll bore you with short excerpts from the workout. This was last Thursday. I’m still having problems with my left shoulder, seemingly a problem with the trapezius muscle, hopefully nothing more permanent than that. So Dan’s been playing around with the format of the work out a bit to get me working up a sweat and improving and reinforcing good technique.

This video is fairly early in the work-out. It looks like my forward hand is dropping too early, and we worked on that later in the work-out.

This video is late in the work-out. I felt more warmed up than tired out, and I think it was going very well. I do notice I’m not opening my left hand at all, though, which is bad. But I don’t think I’m dropping my forward hand as much, and I think I’ve got a decent catch going on.

Well, that experiment didn’t go very well

The Prius beeps and displays a large “Add Fuel” banner on the display. Vicki always starts looking for a gas station almost immediately after it beeps on her car. But with my older cars, I always knew how far I could go after the low fuel warning – on both of my Corollas, it was about 100 km or more. I never ran a car out of gas.

And so I decided to test it. I read on-line that the Prius tank is 12.5 gallons, but I’ve never put more than 9.6 gallons in it. So the last time the low fuel warning came on, I drove 50 miles before filling up. That got me 9.879 gallons. So this time, I figured I’d go 100 miles. After all, the display was showing that I was averaging 40 mph (it’s been really cold and my trip to work is too short for the car to warm up properly) so 11 gallons would be 440 miles, and the warning went off at around 325 miles, so it should have worked out.

So imagine my surprise when I was driving home tonight, and at 75 miles from the low fuel warning almost exactly, this big red warning icon came up on the dash, and the gas engine cut out. I quickly hit the “nearest gas station” button on the GPS, and put on the emergency flashers. I was able to drive on electric only for nearly a mile. Unfortunately the gas station was a mile and a half away. And these days, gas stations don’t carry gas cans. So I walked all that way for nothing.

Fortunately Vicki came to my rescue. Between the gas can and the fill up afterwards, I put in 9.92 gallons. While I was waiting for her, I googled and discovered that the Prius tank might be 12.5 gallons, it has a bladder inside that restricts the capacity to somewhere between 9 and 11 gallons, depending on the temperature. So I guess I was lucky to get nearly 10 out of it. And I guess I’ll start looking for gas 25-50 miles after the warning, rather than 75.