Interview - A Rather Good Guide® for Programming the DX9 for Fixed-Wing Aircraft

All the programming procedures have been independently tested. They work!

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You recently published a Rather Good Guide® for Programming the DX9 for Fixed-Wing Aircraft, could you give our readers an overview?

From Andy Johnson-Laird

Sure — it’s a 620-page technical manual designed to be read primarily electronically (as a PDF file) so that the information you’re looking for is easy to find. It’s written for both newbie’s who don’t really understand radio-controlled aircraft but also has detailed technical explanations for experienced pilots. I decided at the outset that I wanted it to be sufficiently complete that, when it comes to programming the DX9, it should provide all the underlying information that you need — and exclude technical information that, while true, was not something you really needed to know for programming the transmitter.

I was adamant that it should be a document in which it was easy to find whatever information you happened to need now, presuming that you were out on a windy, rain-swept flying field (think Oregon) and you just need to get one simple question answered now. This meant that the document had to have a full table of contents, table of figures, a detailed index, and lots of cross-references — all of which had to be “live” links so that you could click on a page number or a cross-reference and immediately go to that page, absorb what was there, and come back in the document to where you were. In other words, I wanted to make the document more like browsing the Web rather than one of those technical manuals where you spend more time searching for information than you do absorbing the information. Computer geeks of a certain age will know that what I tried to do was to implement Ted Nelson’s ideas from the 1960’s — he was the guy who coined the words “hypertext” and “hyperlink” that we use today for Web pages. (Google search for “Ted Nelson”).

Is the Guide just for the DX9?

Yes and no. It’s certainly written with the DX9 in mind and all the menus and examples were prepared and tested on the DX9, but because Spektrum had the wisdom to make Airware® software common from the DX6e to the DX20. so it covers all of those features that the other models have in common with the DX9.

The iX12 and iX20 also use a variant of Airware® but the graphic user interface is very different as it is created for the Android operating system that controls the touch screen — so the visual appearance on these transmitters’ screens is different from the DX9’s screen. But, again, all of the underlying concepts and features that the iX12 and iX20 share with the DX9 are covered by the Guide.

620 Pages makes it a giant manual compared to Spektrum’s 45-page Instruction Manual. Why is the Guide so large?

Well, I did not set out with the intent to write a giant Guide, but I rapidly discovered that to paraphrase what a friend once said to me, “before you can write about something, you have to write about something else.” For example, before I could write about what the joysticks do, I had to write about ailerons, the elevator, the rudder, and the throttle — and that leads to the need to write about how an aircraft flies (the better to explain why the transmitter has built-in compensation for adverse yaw, for example). Programming the DX9 demands an understanding of some basic aerodynamics merely to be able to under why the transmitter can do what it can do — otherwise, the reader is left with “that’s nice, but why would I ever want to do that?” Also, it drives me bonkers when I read technical documentation that says, “to fix this critical problem, click on the Fribnitz icon and, whatever you do, set the Bazonka field to 42,” but fails to show me what the icon looks like and where to find it, or explain what the Bazonka item is, why it’s happy to be set to 42 and what dire consequences result if it’s set to 43.

As I researched the DX9 (I think the system timer shows I have 300 hours right now), I realized that the more I learned, the more I needed to learn — and that resulted in me taking screenshot (“screen prints”) after screenshot, just to record what I had learned. In total, there are 2,300 screen prints. I also needed to find real-world practical examples where people had solved specific problems. To really understand the solutions, I had to test them and understand why they did what they did and then write about them so others can understand the solutions. By the time I did all of that, the page count was going way, way up — but the beauty of publishing a document electronically is that the page count is of no great consequence. Someone on the other side of the Earth can download a copy of the 620-page Guide without any shipping costs and regardless of the time of day. Shipping electrons beats shipping atoms any day and, contrary to popular belief, when it comes to PDF files, size does not matter.

What motivated you to write this Rather Good Guide?

I’ve worked with transmitters from Graupner (RIP), Futaba, and Spektrum and, I confess, coming back into RC after several decades away from it, I struggled mightily with the concepts, the jargon, and the practical aspects of it — my struggling was as though I had walked into a cocktail party in a foreign land, where everyone was speaking a language I did not know, and everyone in the room knew everyone else but I knew no-one — worse yet, they were all wearing dinner jackets and cocktail dresses and I was the complete odd man out in swimming trunks and a snorkel.

Restating it: I wanted to understand the Spektrum DX9, DX18 and DX20 that I own and, from my own experience, I knew that to really understand something, I needed to write about it. The act of writing about it forces you to slow down, read, research, think — and, of course, ultimately write. Then, if you show your chicken-scratchings to other people and when they read it, they too can understand it, then you know you got it right.

Along the way as part of my research, I discovered Martin Holt’s eBook on the Futaba transmitters and Sherman Knight’s manuals for the Spektrum transmitters for sailplanes (I have a private pilot’s license and used to own a 17-meter DG-400 self-launching sailplane, so really appreciated Sherman’s work).

Good as Martin and Sherman’s manuals are, they still required background knowledge that I did not have, so I struggled a bit with their manuals, too. OK. I struggled a lot — made all the worse because the transmitters are now computer-controlled.

The idea of writing the Guide wandered around my brain for several months and, in early 2019, I started researching and writing the early sections — which really have nothing specifically to do with the DX9, but, as I said, are necessary for readers to understand how an aircraft flies so that then they can understand the need for what the transmitter can do.

One of the sections that pushed me over the tipping point to write the Guide was when I was trying to understand mixing. I read everything I (and Mrs. Google) could find. Even the basics (like why were there two percentage rates) eluded me. I read one posting that called them the positive rate and the negative rate but declined to explain further. That confused me no end — as did the fact that the numeric values for both could be themselves positive or negative numbers. It blew my mind to think of a negative number for the positive rate and a positive number for the negative rate. I spent several hours with my wife sitting in front of me while I used a whiteboard in our conference room to attempt to explain to her what mixing was all about and how it worked. With her help, I finally figured it out well enough to be able to distill the fundamental principles — but it took a looong time.

From the comments I’ve seen, people are very pleased to see the level of detail in the Guide. Was it hard to write?

The short answer is no: I just had to sit and stare at my computer screen until beads of blood formed on my forehead. The longer answer is yes — but for two reasons: the first reason relates to the DX9 itself, and the second reason relates to the technical challenges of producing the PDF file that I wanted. As many DX9 owners will know first-hand, there are several terms or phrases that are used that either teach away from their real meaning or don’t really convey any meaning — at least not to me. Things like “kick points,” “rates,” “absolute travel,” — the list goes on, but for newbies such as I was, these terms might well have been words in Swahili (if you care, they are “mateke,” “viwango,” and “kusafiri kabisa,” according to Google Translate — but you see what I mean). For these mystery words, I had research how these things were being used to infer what they meant, and then I had to back-track and find more descriptive terms. To help the reader, in the Guide, I use both the mystery words and my descriptive terms. I reasoned that if they made things easier for me to understand they might help someone else.

Then, of course, for each programming procedure and real-world example, I had to program the DX9 and test that it really worked — and only then did I write a general introduction to the procedure, take all the screen prints necessary to document it, and, finally, write the narrative in the callouts that describe what you have to do on each screen.

The second major challenge — and one that blindsided me — was that, to produce a highly searchable PDF, I need to find the software that was capable of doing it. I had thought I could just use Microsoft Word. Naïve fool that I was. At one point, about four months into the writing, I broke Microsoft Word so badly that I thought I would give up the whole project — I stopped and spent two weeks researching other word processors and page layout software and none of them were as good as Word, even with all its foibles. Some of Word’s shortcomings had me pulling my hair out: it could produce an index, but the page numbers were not hyperlinked to the actual pages, and creating cross-references was unworkably tedious. Worse yet, working with Word on a Mac, when I exported the Word document to a PDF all the hyperlinks were removed. Overcoming these challenges required several thousand dollars to have a custom cross-reference tool developed by a consultant in Copenhagen, Denmark, and resorting to writing the text using Word on a Mac then switching over to Word on a PC to create the PDF just to keep the hyperlinks! My wife reports me lamenting, “I knew this would not be easy, but I never knew it would be this hard.”

How long did you spend working on the Guide?

I started in early April 2019 until early April 2020 — working on no other project, six days a week, about ten hours a day — and before you ask, on the seventh day, weather permitting, I went flying at our local RC flying club.

I’ve seen RCGroups postings where you make reference your “team.” Who are they?

First and foremost, I have to give credit to Andy Kunz. He’s the lead developer of Spektrum’s Airware firmware that drives the DX transmitters. Via the rcgroups forum and direct messaging, he helped me understand some of the more obtuse aspects of how the DX transmitters work. From what he told me, coupled with hours of experimentation, I was able to distill what I hope people will find a comprehensive and comprehensible explanation for all aspects of the DX9.

Other members of the team are Kay Kitagawa (I’m her husband), who helped me with the editing and provided “executive support” during my darkest hours, Dina Gomez, who was invaluable in reading through the drafts and finding grammatical and punctuation mistakes, and two consultants who I hired. Greg Menton, a fellow club member who’s been flying RC planes since before he needed to shave, helped me test out all the procedures — his struggles to follow what I’d written helped me identify mistakes and what needed clarification. Last, but definitely not least, Dave Hicks, the chief flying instructor at Fly-A-Ways RC Flying Club really went to town as a technical editor on my scribblings, challenging and correcting my thinking and my understanding. I could not have written the Guide without Dave’s insistent and persistent review.

As for me, I did the initial research, the writing, the screen prints, the diagrams, and figured out the work-flow to create the PDF and handled the aspects of publishing the PDF on-line and linking my web site, rathergoodguides.com, with the payment processors. It kept me quite busy.

Thanks to the Internet, Dropbox, and Google sheets, the team members kept on truckin’ through the Covid-19 pandemic — it might even be that the stay-at-home order helped in a unexpected ill-wind kind of way. I suspect that editing the Guide might have presented a more rewarding task than finishing a bathroom or whatever items were on their respective “honey-do” lists.

What’s your background and how did it equip you to write this Guide?

My background as a technical writer was shaped by my education in England — the boarding school that I attended from the age of 8 to 16 placed great emphasis on English literature and language. Exams there were not multiple choice — your grades could be affected by how well you wrote and reasoned — even if you got the answers wrong. Punishments meted out by prefects when I misbehaved (well, when I got caught misbehaving) consisted of “snap” essays (1,200 words on “Subterranean Rumblings” by tomorrow evening!”). When I started working in the mainframe computer industry in 1963, I started as a computer operator, taught myself to program, and then ended up as a technical writer, writing the manuals for a new range of computers — and then went on to be a systems programmer working on the operating system that made the computer run application programs. So, almost inadvertently, I was taught how to write technical documentation. I’ve also spent the last 30 years working as a forensic software expert, testifying in court about software in intellectual property cases — a different kind of writing, demanding a high degree of precision and careful choice of words.

When multi-rotor helicopters, now called drones, first came to my attention back in 2012 (the Freefly Cinestar being the first), I was hooked. It combined photography, videography, flying, and computing (the flight controllers use microprocessors). I immersed myself in the technology of radio-control, FPV, and shooting aerial video that I donated to Oregon Public Broadcasting.

After a few years, I decided that I would get back into RC flying of fixed-wing aircraft and sailplanes and I dove headfirst into the technology of Graupner, Futaba, and Spektrum RC transmitters, receivers, and telemetry. I thought I was diving into a pool of knowledge, but it turned out to be full of concrete-filled with jargon that everyone else on RCGroups understood. Nothing in my background helped the pain in my brain caused by the concrete, but, thankfully, Mrs. Google knows a lot about these subjects, and I spent hours ingesting the Internet, reading through seemingly endless sequences of postings on RCGroups and other forums, trying to answer the most basic questions just for my own education.

What are your current plans? Will you produce other Guides?

First, I need to send my DX9 back to Spektrum — I wore out the thumb roller switch in the course of 256 hours of researching and testing the procedures in the Guide.

I’m already planning a second edition of the Guide that will cover the emerging new developments from Spektrum such as their Smart Technology® and the new breed of receivers that you can program from the transmitter.

I’m looking closely at producing a Guide for the new range of air transmitters such as the iX20, but, it’s not clear how large that market is compared with the DX series.

Are you planning on Guides that will readable on the Kindle, say?

You can already read PDF files on the Kindle — although I confess, I have not tested to see whether the hyperlinks allow you to navigate back and forth throughout the Guide.

Where did the name “rather good guide” come from?

I was talking with some friends over dinner and, after the first (?) glass of wine, I started ranting about the lack of a good manual for the DX9 (sorry Spektrum, but I need to speak truth to power) — a manual that would tell me what I needed to know to use the transmitter, with examples, and present the information in a logical order that made it easy to understand for me as a newbie or even for an experienced RC pilot. When I finished the rant, someone, said: “that would be a rather good manual!”

Something being “rather good” is a rather good example of British Understatement, of course, and means “very good.” I’m hoping that the people who read the Guide do feel that it really is a rather good guide.

Where can people license a copy of the Rather Good Guide for Programming the DX9 for Fixed-Wing Aircraft?

It’s available on my company’s web site: http://rathergoodguides.com/dx9fw. There’s also a 77-page free sample that has the introduction, the table of contents, the table of figures, and five pages of each of the major sections.

Last edited by Jim T. Graham; Apr 20, 2020 at 04:48 PM..
Thread Tools
Apr 20, 2020, 03:05 PM
Thanks for taking the time to publish the interview, Jim.
I misspoke on one thing -- where I said " Airware® software common from the DX8G2 up to the DX20" -- that should really have been "from the DX6e to the DX20."

Cheers
Andy
Apr 20, 2020, 05:06 PM
Registered User
Zoomer-Ron's Avatar
Does this user manual have a section on setting up sailplane crow on the throttle stick, for precision landings? (that's down flaps with raised ailerons, on a four servo wing)
Apr 20, 2020, 05:29 PM
Quote:
Originally Posted by Zoomer-Ron
Does this user manual have a section on setting up sailplane crow on the throttle stick, for precision landings? (that's down flaps with raised ailerons, on a four servo wing)
Hi Don:
No it does not, it's intended for fixed-wing, non-sailplane, aircraft.
I can recommend Sherman Knight's manuals. https://red-sailplane.myshopify.com/ to answer your specific question.

EDIT: I should apologize because the title doesn't make that clear, but I couldn't think of a way of keep the already long title, shorter -- it would have otherwise been "A Rather Good Guide® for Programming the Spektrum DX9 for Fixed-Wing Aircraft (Bot Not Sailplanes)".

Hope this helps.
Cheers
Andy #3
Last edited by ajohnsonlaird; Apr 20, 2020 at 07:32 PM.
Apr 21, 2020, 03:54 PM
Registered User
Zoomer-Ron's Avatar
Thanks #3. I just got the six servo sailplane book. Might still get your guide down the road a bit.

And thanks, Jim T, for the interview.
May 13, 2020, 04:07 PM
Registered User
Quote:
Originally Posted by ajohnsonlaird
Hi Don:
No it does not, it's intended for fixed-wing, non-sailplane, aircraft.
I can recommend Sherman Knight's manuals. https://red-sailplane.myshopify.com/ to answer your specific question.

EDIT: I should apologize because the title doesn't make that clear, but I couldn't think of a way of keep the already long title, shorter -- it would have otherwise been "A Rather Good Guide® for Programming the Spektrum DX9 for Fixed-Wing Aircraft (Bot Not Sailplanes)".

Hope this helps.
Cheers
Andy #3
Wow. All those pages and nothing on sale planes! I don't know whether that is sad or impressive. LOL. I wish someone would do as thorough a job in the DX9 with Helis!
May 13, 2020, 04:55 PM
Quote:
Originally Posted by turnorburn
Wow. All those pages and nothing on sale planes! I don't know whether that is sad or impressive. LOL. I wish someone would do as thorough a job in the DX9 with Helis!
Yeah -- and the ultimate irony is that I used to own and fly a 17-meter self-launching sailplane (a DG-400).

But the truth is that there is a lot of depth to Airware using on the DX product range. The other problem is that, if you're relatively new to the hobby, it's hard to read about how to program the transmitter without understanding why you need to program the transmitter -- if you see what I mean.

As I mention to AndyK this morning, the general rule seemed to be: "Before I could explain anything, I had to explain something else...."

I have been thinking about a Guide for helis, but, as the sign on my office wall says, "There's been a remarkable increase in the number of topics about which I know absolutely nothing." Helis is one of those topics.

Cheers
Andy #3
May 13, 2020, 05:06 PM
AndyKunz's Avatar
Quote:
Originally Posted by turnorburn
Wow. All those pages and nothing on sale planes! I don't know whether that is sad or impressive. LOL. I wish someone would do as thorough a job in the DX9 with Helis!
If you can find the DX8 helicopter book by Bert Kammerer it covers the subject very well.

Andy
May 14, 2020, 04:28 PM
Registered User
Zoomer-Ron's Avatar
Quote:
Originally Posted by ajohnsonlaird
Hi Don:
No it does not, it's intended for fixed-wing, non-sailplane, aircraft.
I can recommend Sherman Knight's manuals. https://red-sailplane.myshopify.com/ to answer your specific question.

EDIT: I should apologize because the title doesn't make that clear, but I couldn't think of a way of keep the already long title, shorter -- it would have otherwise been "A Rather Good Guide® for Programming the Spektrum DX9 for Fixed-Wing Aircraft (Bot Not Sailplanes)".

Hope this helps.
Cheers
Andy #3
Quote:
Originally Posted by Zoomer-Ron
Thanks #3. I just got the six servo sailplane book. Might still get your guide down the road a bit.

And thanks, Jim T, for the interview.
So, Andy, I bought your guide too. Thanks.
May 14, 2020, 04:58 PM
Quote:
Originally Posted by Zoomer-Ron
So, Andy, I bought your guide too. Thanks.
Thanks, Ron. You're all set for some serious reading!
I have Sherman's documents too. He blazed the trail....

Cheers
Andy #3


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