CraigMattson.net

Building a Custom Flight Controller for an Airbus A320

12 January 2022

Continuing on from my Christmas Blog Post series, this one might very well be the start of building an A320 home cockpit but I make no promises here. One might even call it ramblings of a software developer who has discovered the hobby of 3D printing.

A trip down memory lane...

Among my earliest childhood memories around the Amstrad CPC6128 is one of my favourite games - Acro Jet. It's not a particularly interesting simulator to retrospect on, but the mind of a 4-5 year old can be quite powerful. Neither were F-16 Fighter for the Sega, Top Gun on the Nintendo Entertainment System, and any of the other many flight games on early 8-bit computers and consoles. Fast forward some 5 or 6 years and Microsoft Flight Simulator for Windows 95 was the new hotness. Armed with the Australian Scenery Pack, one could now fly under Sydney Harbour Bridge and... that's about it. Suffice to say, the complexities of aircraft never really hit home - nor could I ever land the planes, no matter the tutorial.

While at university, I saw Flight Simulator X in the bargain bin at one of our common game stores. It was the Accelerated pack, with manuals and all the glossy artwork. In there were several airliners and even though Melbourne Airport was pretty plain, it certainly resembled it more-so than the earlier games. What really enticed me to look at it was the multiplayer aspect - having the ability to be ATC or communicate with someone playing the ATC role. I would go on to play on and off for several years learning bits and pieces - but never taking it too seriously.

Some time around 2014, I had come across some YouTube videos on an Airbus A320 modification for Flight Simulator X. I hadn't looked into Prepar3d or any of the other flight simulators at the time, but this video would describe in detail how to do a cold start, key in your flight path, fuel planning and had some pretty impressive sounds and realism - compared with the stock A320 anyway. This got me interested as it was presented in a very palatable way. Checklists, flying and landing. I would soon after buy the aircraft and learn how to fly the A320 and have a lot of fun doing so for many years to follow. I've been through other simulators as well, including the defunct Flight Sim World, but suffice to say up to the Microsoft Flight Simulator 2020 launch, it's a plane and game I would return to time and time again.

When Flight Simulator 2020 finally released, I had a few weeks to play before my son was born. It was incredible. The stock aircraft were pretty well featured, if not a bit too easy to fly and the scenery was substantially improved - particularly for Sydney Airport (I'd purchased several airports over my time in FSX to improve realism). But... when you start building up those flight hours, get random crashes - it can leave a sour taste behind. Enough at least that I hadn't really played it for over a year since picking it up recent weeks again.

Some 100GB update later, and I note that most of my modifications have been removed, broken or replaced and unfortunately it felt like I was at step 1 all over again (this game has a serious problem in having many tools to modify the game). I remembered somewhere along the line, an open source effort to replicate the Airbus A320 was underway and thought I'd go and check it out. This didn't go so well - involving a total re-install of the game at a further 150GiB. After getting it all up and running again - with the A32nx mod installed (and of course, with a few liveries) - I'm ready to check out where I left things.

Comparing Flight Simulator X (and Aerosoft A320 mod) to Flight Simulator 2020 (and A32nx mod), you'll immediately notice a few things:

  1. The graphics in FS2020 are incredible compared to FSX - the scenery, motion, etc... feels a heck of a lot more realistic.
  2. The camera itself is also tilting, I guess just as your head would in a real aircraft.

For #2, this presents a real problem when trying to set any of the aircraft's flight control unit controls - because as you're trying to set an altitude while scrolling your mouse wheel, you may - due to motion - start changing heading, turning off controls, or setting your vertical speed for a nosedive. Suffice to say, this level of "realism" is completely useless for functionally while playing the game.

I've always wanted to build a home cockpit of sorts - there'd be a number of caveats of course. It would have to be compact and modular enough to store away when not in use. It'd also have to be for an aircraft I fly a lot. I'd want it to be familiar enough - but no need to be a perfect replica (I'm not a pilot after all, this is purely for fun) and I'd have to have fun building it as well. Suffice to say, the issue of motion annoys me so much that turning it off removes that feeling of realism so that really leaves me with building a modular set of flight controls.

Building a home cockpit is as old as Flight Simulators themselves, so there's a lot of material around on how to build one. Two of my favourite ones include The Warthog Project and Heli Mech who builds a Boeing 737 cockpit. The latter channel goes through how to build a lot of panels and components a number of different ways and his style has given me a few ideas on how I could similarly approach an Airbus A320 variant - at least in appearance. Over time, I'm sure I'll be adding a CNC machine to my collection but until then, I want to exhaust what it is that I can build using stuff I already own before investing in more garage clutter.

What can I 3D Print?

Heli Mech recently released a video using mostly off the shelf components and some 3D printing on a printer that has a much larger print bed than I do. It would be fairly easy to copy this design and Airbus-ify it, but if at all possible - I'd want to try and get it backlit (this design doesn't) and using custom components to mimic the Korry switches instead of using the KD2 buttons this guy uses. There are several videos on YouTube that make use of Laser cutters and Acrylic to cut out 3 plates - usually a White layer, and a couple of transparent layers that will be painted and etched into giving a professional looking finish to a panel. To get the equipment to do this will set you back a good $1,000 after all is said and done - so to start out, I'd like to see how far I can take this particular project to get an acceptable result.

To get started, I really need to see how I'm going to get light through plastic. I begin by designing a 90mm x 90mm canvas at different heights, with text all over them to see what might render well. I've chosen variations between 2mm and 5mm - understanding that 5mm is going to be far too large, but if the text is legible - this might be a trade off I need to make. I then load this into the 3D Printing software and take a look at how the layers are going to print. Obviously the smaller text is going to be tricky - but with a calibrated printer it could be made to work (after the 6 months it's had pushing out Christmas decorations, I'm sure it's anything but level at the moment).

Using some scrap white filament, I'm printing out at 100% infill as the light will need to "push" through and something tells me that light isn't going to be too happy if it's not dense enough. Also - this isn't using transparent filament, it's an opaque white - so no doubt thickness and some seriously bright lights will be required here. Lucky I just finished a project with leftover LED strip that will run super-bright.

After printing, I'll need to use some paint. From the Christmas lights project and the PVC painting, I have some Rustoleum 2x paint - the same as The Warthog Project uses in his example, so fingers crossed at this point that i'll be able to paint that on, use a file and scrape back some of the paint. The result is... not good at all. No light shining through, but I did finally get to an acceptable and legible height. 5mm to be precise is a good height to be totally readable and work with paint being scraped back.

Figure 1 - 3D Printed Plate after scratching back paint.

Anyway - that's it for today. I'm going to try and keep these blog posts a little shorter and more frequent as I go. I've already got some working examples of Korry switches (that work) and plenty of gear arriving (potentiometers, rotary encoders, 7 segment displays) - so hopefully within the next couple of weeks I'll have some kind of prototype up and running to improve the flight simulator experience.

 


Building a Synchronised Christmas Lights to Music Display - Part 7

05 January 2022

With Christmas now over, the lights have come down and apart from what's left on the roof - it's packed down fairly easily. The show itself ran until the 28th December 2021. I originally planned for it to run right to the end of the year but with no viewers after Christmas Day, it was time to turn it off.

Suffice to say, the actual show was pretty uneventful (in a good way!). No police called, no neighbour complaints, just a lot of happy people coming by in groups - 1-2 an hour. I didn't advertise the display but it was organically found within the first hour of the first show and posted on the local Facebook groups. No further posts up until the last few days leading up to Christmas itself. Suffice to say if I had posted there, there'd certainly have been a lot of visitors which no doubt would have started to upset those in the street and attract the attention of those wanting to impose restrictions on lights. There are plenty of stories in the community this year about councils cracking down on large gatherings requiring some displays to register as 'events' and have traffic management plans in place so I'm glad I didn't have to face that this year.

None-the-less, with a successful light display for 2021, I thought I'd catch up on the few things that occurred during the show of notable interest.

Helping the viewers know what it was they were looking at

As it turns out, not many people knew the display was synchronised to music. Furthermore, after around a minute in the first week - people would drive off - presumably not seeing anything that would indicate that there is music here, even though each sequence would display the FM frequency to tune into and intermissions for the same. I thought the singing trees themselves may have been enough of a hook to understand that something more is going on - but alas, no. So after a night of coffee and code, I'd put together a poster and a web app that would enable viewers to see the schedule, see what's playing, control the display by selecting something to play and allow them to boost a small speaker I'd place in the letterbox for the rest of the run.

Figure 1 - Web App Playlist

The concept was simple. Falcon Player has a full REST API available, as well as the ability to intercept UDP messages for the Multisync protocol - which tells the other "slave" players what's playing and what timestamp it's up to. I would build a basic poller with cache that would talk to both the Speaker Pi and the main Falcon Player Controller - but also listen to the Multisync broadcasts for immediate changes in status, and time position (otherwise, you've got to start writing 1-2 second pollers). To do this, I'd set up a VPN between my home router (a Ubiquiti Dream Machine Pro) and the web server. This created some sort of proxy that meant any damage to the show via the web page would not impact my home network.

The Web App on request would ask the poller for it's status, playlist and allow requests for a temporary volume increase to make it's way through to the Speaker Pi specifically. The frontend is a simple Angular SPA - nothing fancy going on here. Just a Flex Layout with a tabbed style interface and some material design popups. A poster would be visible on the letterbox with a large QR code to access the webpage. For future years, I'd like to incorporate some sort of code to flash up that you key in to confirm you're actually standing in front of the house to avoid abuse, but for this year it was sufficient to just have a kill switch if need be to turn off requests or speaker boosts. I'm also in favour of not putting hurdles in front of people, unless I need to due to exploitation of whatever is displayed.

Figure 2 - Web App Diagram

The speaker setup used a Romoss 30,000mAh battery, a Raspberry Pi 2, a TP-Link AC750 router in Client Bridge mode and an old but fairly good quality portable speaker. I had also 3D Printed a button to stick on the letter box, but very few used it so it was removed after a week - it really needed to be incorporated into a prop or something else interactive I think - and perhaps with Covid-19 fresh in everyone's mind, perhaps people didn't want to press the button just in case. The first time I had set it up, for a few days the player would randomly freeze. I thought it might have been low power or the fact this Pi is probably 6+ years old. I also tried a Pi Zero - but having to add USB soundcards made that impractical and they'd just stop responding to Multisync packets. It turns out that after a bit of investigation of the system logs, that the SD card might be faulty. Swapping the SD card seemed to fix the issue, not sure if the SD card itself was faulty or what...

The sound quality itself was fine, but you could tell that there was a fair bit of "catch up" when using wireless to get the best 'sync' possible. I don't have a particularly strong wireless access point near the front of house meaning the wireless strength was pretty poor itself no doubt contributing to the problem. It also highlighted why you probably don't want to run your show from wireless only as you might find your lights slightly delayed and 'choppy' too.

With Covid-19 restrictions requiring QR code scanning, people are so used to scanning QR codes of any kind with their phones. With a large enough one on a poster, people will get out of their cars to scan it. This improved the viewer rate, and the kids that you could hear in the car certainly seemed to enjoy it more when the Bluey remixes and Polar Express were available. Overall, a win for having an app that viewers can select and play what they want to hear on the display.

Fast repairs - and boy you're going to want to practice this.

At the end of the day, the display is all DIY. From time to time you'll mess up a solder joint, or maybe you'll not put enough silicone in to make the string of LEDs waterproof. The first failure I had was all down to a bad solder joint from possibly the very first LED strip I put together. The symptoms were that it'd stop working - especially after a bit of light rain. A bit of a wiggle would bring it back to life - but of course it had to be one of the ones that were on the roof.

Other failures included:

  • One particular snowflake that had multiple bulb failures - this is where you will come well acquainted with scotch locks and other joiners. You'll probably also want to buy extra strip or strings to combat any failures you might have during the show.
  • In the small matrix, one of the bulbs lost colour intermittently - this wasn't worth the hassle of cutting it out as the Data line was being passed through fine.
  • In the larger matrix, one pixel had caused significant flashing - I didn't have a spare for this kind of string so it remained flashing during the show.
  • The FM transmitter I bought could barely make a couple of meters so I needed a replacement that would at least get a 20m range. I'm sure the original one could have been modified to go further but alas - fighting with it in the first week wasn't pleasant.

What people really like in a display.

When some general public viewers would rock up while I was outside viewing / recording / anything really, most would start with some shock with what they were seeing (i.e. all new), eventually realise it was synchronised to music and then they would proceed to talk about others in the area. The noticeboards and other local groups on Facebook also indicated the same. It would appear that the more lights there are, the better - but they also like props and given the sheer number of them this year (including the next door neighbours inflatables display), it's clear that despite it being unique that you do tend to come across those who think you can buy the stuff straight out of Bunnings.

What I take away from this is that the general public love lights and displays. They don't think too much about it (the occasional one does), and they will move on to the next and comment later about how awesome entire streets are when everyone's working together. And that's really it. If you're in a street with lots of lights, your street becomes the talk of the town - and you get your driveways clogged with cars just as another local street does on a routine basis.

To that end, whatever you make - be it singing, plain, inflatables, people will generally like it if the lights light up. The downside to a fully flashing display is that I felt that I needed to turn it off after 10PM - at least switch it to a non-blinking display. It'd would be too distracting if it was blasting in your window or down the street.

What to do for 2022's display?

I get asked this one a lot. I'm still not sure what I plan on doing, but I'm sure it'll involve more focus around props. People really love the props that move and so I might even look into waterproofing up some stepper motors and giving that all a go. Not sure how that will pan out, but hey - check back here in September and I might have more of an idea.

If you're thinking about doing a display yourself though for the first time, I'd recommend you grab yourself some pen and paper and start drawing out a layout. Pixels will go on sale in the next month or two and paying for shipping by boat will be far cheaper than any airfares you might have to pay otherwise. I'll probably be ordering several thousand pixels soon(tm) even if I don't fully know what I'm going to do with them ... yet.

In the meantime, this will be the last post on the Christmas Lights display for 2021 but there are more 3D printing projects coming up. So much for this being a coding blog hey.


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