How a little HP-50g program mutated into an iPhone app

[Peter Murphy (Livermore)]

The program was developed by a pilot to do refueling calculations; the pilot was an engineer, and an experienced 48/49/50 user.

He generalized the program for other aircraft, taught himself programming for iOS, and ended up with a nice-looking application called Aviofuel.

Perhaps pilots and others familiar with such matters (and even with this particular app) will have comments. I think it's a nice and relevant story.

The mutation story is here:

http://www.aviobot.com/2011/aviofuel-story

The app is described here:

http://www.aviobot.com/

[Eddie W. Shore]

Very nice app, well done. This gives me something to look forward to do on lunch breaks this week: find out what these terms mean.

[Norman Dziedzic]

Very Neat. Thanks for sharing.

I am on a similar quest but only at the beginning of my App. We already had a mac book so that was not the hurdle is would be for many. Objective C is a bit strange for someone like me out of programming in C for a long time but the basic stuff is ok.

What I really need to find a way to do is mimic the multiple equation solver of the 50g which is no small task. All my equations will have closed form solutions so I don't have to do any iteration but just thinking of parsing and re-arranging equations programaticaly is a little daunting. But, I'm starting a chunk at a time with it and it really is pretty fun when I get the time to work on it.

[Luis Gonzalez]

Hello, I'm the AvioFuel developer.

I'm glad you liked the 'mutation' story. Thanks a lot for your comments.

I've been using the HP48/49/50 all these years for many pilot-related tasks, such as aircraft performance calculations, flight-time logging, flight planning, weight&balance calculations, and so on.

Nowadays I use the iPhone and the iPad. I still love my 50g, though. In fact, I use it a lot for app development.

If anyone here wants to play with AvioFuel, I can provide Promo Codes to download the app free of charge from the App Store. Feel free to contact me.

Regards.

[Norman Dziedzic]

Quote:

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I spent my free time during the following months learning as much as could about Cocoa and Obj-C, reading blogs, tutorials, watching videos and reading books. I didn't even plan to release anything on the App Store. All I wanted was to take advantage of this little magical device for my own needs, to solve my own problems.

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This is exactly where I am right now. My son keeps asking me if I'm still working on the that "app thing". I'm sure I have months and months ahead of me. The developer information online from Apple is pretty amazing but did you find any other resources particularly useful. I have a "theach yourself iPhone App developement in 24 Hours book" but I think it is a version old so I'm looking for other places to turn to for more recent information.

Thanks again for sharing!

[Luis Gonzalez]

Quote:

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The developer information online from Apple is pretty amazing but did you find any other resources particularly useful. I have a "theach yourself iPhone App developement in 24 Hours book" but I think it is a version old so I'm looking for other places to turn to for more recent information.

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You can find two great iOS development courses on iTunes, both of them for free:

- Stanford University iPhone/iPad Development Course, by Paul Hegarty. <- This is a must-see. Download the slides from the course site and follow the lectures on iTunes. I learned a lot from this course. Link: http://itunes.apple.com/WebObjects/MZStore.woa/wa/viewPodcast?id=473757255

- Madison Technical College Advanced iPhone Development, by Dr. Brad Larson <- Also very good. It dives into more advanced topics. Larson is the author of Molecules and Pi Cubed, two great apps. Link: http://itunes.apple.com/itunes-u/advanced-iphone-development/id407243032

Books (You can find most of them on Amazon):

Basics:

Learning Objective-C on the Mac, by Mark Dalrymple and Scott Knaster -> My first Obj-C book. Great for beginners.

Cocoa Programming for Mac OSX for Dummies, by Erick Tejkowski -> I learned the basics of Cocoa with this one. Very good read, easy to follow.

Beginning iPhone Development, by Dave Mark and Jeff LaMarche -> My first iPhone development book. Very good. Easy read. It gives you a very good foundation.

iPhone App Development: The Missing Manual, by Craig Hockenberry -> It covers the whole app development process, from the beginning to the end. You'll need basic Cocoa Touch and Obj-C knowledge in order to get the most out of it.

Intermediate/Advanced:

Core Animation, by Marcus Zarra and Matt Long -> Teaches you everything about Core Animation on iOS. I strongly recommend it if you wanna give your app a distinctive touch.

Pro Core Data for iOS, by Michael Privat and Robert Warner -> Once you get enough experience with basic iOS development, you'll realize sooner or later that you need to use Core Data for everything but the most basics apps. I found Core Data a bit complicated and obscure at first. This book helped me a lot.

iPhone 3D: Developing Graphical Applications with OpenGL, by Philip Rideout -> If you plan to develop 3D graphics apps (or games), this is a must. It covers OpenGL ES with lots of examples. You'll need a good C++ foundation, though.

Web:

There are plenty of great sites about iOS development. I think stackoverflow.com and iphonedevsdk.com are both extremely useful for beginners.

Regards, and happy coding! :-)

[Norman Dziedzic]

Luis Thank you very much! I found out that there are several different Stanford classes in the iTunes store (different semesters). The first one I got was too old. Looks like the latest will require me to update the OS on our mac book pro.

But I hadn't found the Madison Technical College one.

That looks like a great collection of references. I'm already finding I want/need to do things I can't with the standard controls.

Funny you mentioned a good C++ background. I have a mediocre C++ at best :-) I'm old enough to have to take FORTRAN at school and tought myself C and a little C++ over the years.

But strangely enough, I have been developing industrial machinery controls for a long time and the Interface Builder is very much like the programs we use to develop for machinery.

Take Care