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Anybody playing with a DIY HUD?

plehrke

Well Known Member
Patron
With cheap "HUDs" available for cars these days, has anyone attempted to adapt one for use in their RV? Some are as cheap as $15 that has your smart phone laying on glareshield, some around $50 that take a data feed from your cars OBD2 port with pretty canned automotive displays, and some up around $2-300 that connect up using a wifi link (like the Hudly being used by GRT shown at OSH last week).

With all the tinker-ers, diy-ers, and gadget people in the RV community, I got to think someone has been playing around. I have a couple selected on Amazon I want to get to play with but thought maybe a quick post here may net me a few ideas.
 
Sort of. I have an iOS augmented reality app that simulates a K-14 gyroscopic gunsight. It's kind of cool, but really needs some optics to allow your eyes to focus at infinity. Havent found much that either has an sdk or would be reasonably hackable as yet.
 
Having seen the HUD that Greg at GRT is working on, I'm going to let him do the tinkering and fine tune it. Really awesome. I'm upgrading the panel in my 6A with GRT and that little puppy is definitely going to be a part of it.
 
Auto Huds

I've looked at them, but they are so specific to cars, they are pretty useless, and the sunlight is far harsher in an aircraft. It's a good idea and if anyone has any ideas, I hope they add them here.

It would be interesting to see if you can use a portable projector for lumens. I'm watching this thread. My next project is a good candidate.

RV-3 kit, but spar forward is totally custom/not Vans. Corvair power with a turbo-electric-hybrid-boost; I'm looking for 140hp up to 15,000'. I will completely redesign the cockpit like a glider. Highly reclined, center console, no panel. HUD would work very nicely leaving the center console just for switches.

-Bruce
 
Projectors...

Google 12v projectors... they're cheap and would totally work. Maybe use a teensy 3, raspberypi or a chromebit. If you run the chrome OS you could project Avare (https://apps4av.com/avare-overview). You need some kind of pointer device for that as it's obviously not touchscreen. It's open source, so you could build hotkeys on the dash too.

For the air/engine data, I made a dac board that uses an off the shelf arduino Pro Mini via USB. https://sportvfr.blogspot.com/

I still need to test it, but it's just assembling off the shelf, it will need some futzing, but there's no black magic.
 
Hi Bruce,

Not to hijack this thread, but I'm apparently late to your sportvfr party. I read through the blogspot posts, & I'm wondering if there has been more development since the last post in 2016. I can build just about any electronics related hardware, but I'm dead in the water with software/firmware. Do you have something closer to a 'cookbook' that shows how to get at least the engine monitor up and running? Ideally, I'd like to see something that will work with an android phone or tablet, to avoid mounting a CarPC in my RV-4's non-existent panel space.

Feel free to refer me to another thread, or PM me, to keep from diverting this one.

Thanks,

Charlie
 
What is this?

I want to get this thread back on track... I found this picture on google image search, but I couldn't get access to the site. Anyone know what it is?

20u1q38.jpg


Ok... so let's say we can make a semi-transparent display that shows nicely at night and daylight. What should really be on it?

Before I get started, I have dual G3X in my RV-4 now, it is very effective at displaying all information. So I may take a minimal approach to the HUD becauese I have a robust heads-down alternative.

That said; I don't want to waste this very important "eyes outside" space on things that don't matter. So it should be only what I want to see outside.

The most critical basics: (I'd want this in "simple mode")

- A positive horizon line for orientation whilst through obscured horizon
- AoA (when bellow 2x stall)
- "All Green" - No Master warning from ECAM

Less important (Other "stuff" which I'd like to play with to see if it adds value or just clutters)

- CDI
- COM Freq and Station
- TX signal
- Altitude
- Airspeed
- Heading
 
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The most critical basics: (I'd want this in "simple mode")

- A positive horizon line for orientation whilst through obscured horizon
- AoA (when bellow 2x stall)
- "All Green" - No Master warning from ECAM
I'm a really big fan of the "boresight"/waterline indicator and velocity vector display. Add an AOA bracket that's fixed relative to pitch, but drifts with the VV for wind, and you have an excellent tool that shows the relationship between AOA and flight condition better than anything else.

Several military aircraft use that system on the HUD for landing. Good explanation here: http://www.f-16.net/forum/viewtopic.php?t=14493

I've only used it in PC sims but it's incredibly intuitive, once you see it.


In general, though, I'm not interested in a HUD unless it is truly focused at infinity. I've used pseudo-HUDs in cars (both factory installed and portable) and they just don't do it. I'd rather just have a small box there with a real display.
 
I want to get this thread back on track... I found this picture on google image search, but I couldn't get access to the site. Anyone know what it is?

20u1q38.jpg


Ok... so let's say we can make a semi-transparent display that shows nicely at night and daylight. What should really be on it?

Before I get started, I have dual G3X in my RV-4 now, it is very effective at displaying all information. So I may take a minimal approach to the HUD becauese I have a robust heads-down alternative.

That said; I don't want to waste this very important "eyes outside" space on things that don't matter. So it should be only what I want to see outside.

The most critical basics: (I'd want this in "simple mode")

- A positive horizon line for orientation whilst through obscured horizon
- AoA (when bellow 2x stall)
- "All Green" - No Master warning from ECAM

Less important (Other "stuff" which I'd like to play with to see if it adds value or just clutters)

- CDI
- COM Freq and Station
- TX signal
- Altitude
- Airspeed
- Heading


It's Don McNamara's old "Smokey" you can ask him directly. :)
 
Thread drift... I want to know more about that throttle handle... :)

That comes from Thrustmaster FLCS system / PC gaming throttle controller . It looks like the stick grip is also part of the Thrustmaster system. I had one when I was a kid.

On the HUD front. A local Annapolis company is *working* on one, but I'm not sure what the status is:

https://epicoptix.com/epic-eagle/
 
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RV-8 N8RV "Smokey" by Don McNamara

http://rv-nation.blogspot.com/2013/01/best-rv8-military-cockpit-i-have-seen.html

It would appear he took a Thrustmaster FQRS, chopped it off the base and slapped it onto a standard throttle quadrant. It's pretty interesting, but at some point I'm not playing an organ, I'm flying a plane. Great he can start the engine from the stick, but he can't set prop or mixture without letting go. All the same, hat [switches] off to Don.

The product is discontinued, but you can still find them used.

http://www.thrustmaster.com/en_US/products/hotas-cougar
 
I would Google F-18 and F-16 HUD pictures, and delete stuff you don't think you need.The F-18 HUD was originally designed as the primary flight instrument, and certified as such. The F-16 was not. PFD displays ended up going with the scales/tapes for altitude and airspeed, vs the digital boxes the the F-18 used. I prefer the less cluttered digital AS and ALT for a HUD, but it is easy to blow through an altitude when climbing at 8 or 10K feet/min. The digits for altitude are a blur. For instrument flight the scales are better than digits.

I might try a cheap HUD myself.

Yeah interesting picture. I am guessing the red "pickle" button is a PTT, but I am wondering what he uses the "G-override" lever for on the lower portion of the stick. LOL
 
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34nli1k.png


So this is minimalist, The "pitch director" is something I made up. At large Alpha it's an AoA, in a climb it directs pitch for a climb airspeed (100kts or whatever), in cruise it uses a single bar to directs you to pitch for the next 500' increment in cruise and switches to AoA as that gets large. It is consistent that that the arrows tell you which way to push the stick.
 
Flt path marker

Don't try to reinvent the wheel. Look at your video games and see what was invented 50 years ago for the HUD. I have been flying with a HUD for over 45 years and they work.

If you have a FPM to present, use it. Don't try to make some kind of combination pitch indicator/AOA.

There is a good reason the symboligy used in the first fully integrated nav/weapons delivery system is still being used today. in both Military and civilian systems.

The symbols, their placement and function work.
 
Don't try to reinvent the wheel. Look at your video games and see what was invented 50 years ago for the HUD. I have been flying with a HUD for over 45 years and they work.

If you have a FPM to present, use it. Don't try to make some kind of combination pitch indicator/AOA.

There is a good reason the symboligy used in the first fully integrated nav/weapons delivery system is still being used today. in both Military and civilian systems.

The symbols, their placement and function work.

On target. I'm partial to the Viper HUD, but I just want to see any HUD right now!
 
Skipping the FPM, is skipping the best part of the HUD. It even gives you a really accurate, smooth AOA, without any air instruments. The difference between where the airplane is pointed, and where the FPM is, is your AOA, if you are straight and level.

I think I would used airline style scales for airspeed and altitude, vs the Vipers.
 
MGL - Dynon DIY HUD Development Project

Along with many other pilots I?ve always wanted a HUD in my plane and have explored many possibilities through the years. After reading the previously mentioned kitplanes Magazine Article on HUD's in experimental aircraft and how Grand Rapids Avionics is integrating a generic HUD with their EFIS I bought a similar HUD sold as a car HUD that will accept an HDMI video input and a small group of us have started our own experimental avionics HUD project. I?m convinced now having my own HUD is very close to happening.
The big thing here is I have a HUD projector that can be seen in daylight (14,000 nits), it?s not overly bright but it works in sunlight, it has good enough resolution (480x240), and is full color (not all colors work well on HUDs in daylight but the ones that do are there). I first tested the HUD using the straight VGA Video Out from both the MGL Odyssey and MGL iEFIS Explorer through their VGA output port and then into a VGA to HDMI converter and then into the HUD projector. At first only the VGA video from the Odyssey worked correctly but recent iEfis VGA SW updates have made it compatible also. But to optimize using the straight VGA Video out from the iEFIS requires a user MGL screen design that keeps as much Black background as possible with critical HUD data superimposed on this black background like you would want from a HUD, this worked but it makes your panel screen and the HUD both into HUD screens, not what you really want.

So we now have a small project team using a Raspberry PI microcomputer to read and process the MGL serial Blackbox data stream and then output this as a HUD formatted HDMI video signal into the HUD projector to create a custom HUD display designed for MGL Efis users (Odyssey and iEFIS). Since were community here on VANS forum were also writing our SW to be Dynon serial data compatible (MGL or Dynon data is selected in the configuration file read at startup).

The HUD?s were using so far for development are pretty cheap (around $300) and take a direct digital HDMI signal that appears to be good enough for experimental aircraft usage. The HUD can also display iPhone and Android phone video out (not of interest to us right now).
The Raspberry PI microcomputer costs about $26 to $35 and has a built in HDMI interface. Were writing the SW in the Python programming language on the PI. So far we can process and display on the HUD real-time attitude, airspeed, altitude, GndSpeed, Mag Heading, Gnd Track, and the Alt Baro Setting. Much additional data is being read but not yet displayed. Development continues at our part time pace. Were kind of using the F18/HUD display as base line for this early SW development. Were shooting to have 4 selectable HUD displays 1-Nav, 2-Appch, 3-Maneuvering, 4-Special Purpose (let your mind fill in what this could be). When completed the SW should be available for all MGL and Dynon users and will hopefully setup through its configuration file. It doesn?t send data to or try to control your EFIS so it will be a passive addition to your avionics.

Any serious Raspberry Pi developers who might be interested in joining our little GitHub group send me a PM. Some development pics are available on the MGL forum.

Kitplanes HUD Magazine article: http://www.kitplanes.com/issues/35_10/builder_spotlight/Heads-Up-GRT_22196-1.html

MGL Black Box Serial Data Feed Details (data available for HUD display).
http://kb.mglavionics.com/article/AA-00807/7/EFIS/MGL-Black-Box-Data-Feed.html

Check the Dynon and Skyview pilot manuals for the EFIS SERIAL DATA OUTPUT Format (available real-time data) for their RS232 port.
 
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Cecil - this sounds like a very exciting project.

I'm curious... so far some reviewers of the GRT solution grouse about the car HUD devices not being focused at infinity. Is this an aspect you are hoping to overcome with your development, or one of those things one has to make peace with in order to have an affordable HUD?

I have GRT avionics in our aircraft and would love to have a HUD. So far I'm not enamored with the GRT solution as the car HUD devices seem a bit "kludgey". Too many wires and adapters required to make everything run. I am liking GRT's idea of using a dedicated microcomputer (compute stick) to do the massaging of data from the EFIS.

One important feature for me is the ability to have the HUD image inverted so the projector can be mounted below the HUD combiner glass. I suspect this is a pretty simple software switch, but I don't write software code so may be out to lunch. Nevertheless, it's a feature which is pretty much mandatory if considering applications outside the world of RV's.
 
DIY HUD

The key to our project is that we are developing an open source HUD SW processor with an HDMI video output so it should be able to feed any HUD system with a HDMI input. One of our team does want the video flipped for an on the glare shield mount so that option will be in the cofiguration set up file.

Yes most car HUDs are not set up for an infinity projection, but my test unit (same as the GRT unit) in my bench out the window tests looks to be focused about at the prop and I think it’s acceptable.

The Epic Optix HUD I believe will take an HDMI video input (I’m checking now) and it’s focused at infinity so that commercial unit made directly for aviation would provide a more perfect projection, at a higher cost (about $1700 right now).

The MyGoFlight HUD unit appears from the pictures I’ve seen to use the same projection unit as the GRT HUDLY unit (their documentation doesn’t say its projected to infinity?) and their working toward an FAA certification (approx $20k installed?) so near infinity may be good enough for the FAA.
 
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If these guys will have me, I hope to add Garmin?s serial stream to the mix of selectable protocols the HUD processor can support.
 
Thanks for the clear, concise reply to my questions, Cecil. This sounds like an excellent project indeed! I'm a software dolt so I won't be volunteering, unless you want a high quality generator of bugs! LoL
 
FWIW, I have one of the new Hudly units gathering dust on my shelf. I really like the performance of it in the car, in daylight. Extremely readable, and even though it's not focused at infinity it feels seamless to glance at it.

I stopped using it in the car after about a week though, because the WiFi connection between my phone and the Hudly won't stay connected. Hudly says this isn't a problem with the Hudly, and they are "sort of" right. My phone is set to use WiFi when available to save on data charges, and doing so means it'll hop from known WiFi to known WiFi to find a signal that has internet access. We have city-wide WiFi here that has reasonable, but not perfect, coverage... When I drive into an area where I am covered, the phone switches to the local WiFi, and drops the Hudly connection. Not very useful if you're using the Hudly for driving directions.

Hudly's solution is to turn off WiFi roaming. Not a solution for me, sorry.

However, the Hudly unit itself would work well in the airplane if I had something to supply data to it. This talk of using a Raspberry Pi makes me wonder if we should be combining efforts with the Stratux team. My Stratux has GPS, AHRS, pressure ALT, and traffic and weather via ADS-B. And the Pi has HDMI out. Surely we could leverage all of that and have a combined device that gives useful heads-up info on the Hudly (wired via HDMI) without losing the traffic info already served over WiFi to our tablets/phones?
 
Rob - if you wanted to liquidate that Hudly I might be interested... i have GRT equipment so feeding the Hudly data is relatively easy for me.
 
Hudly HUD

I use the Hudly Classic in my plane and it works very well, except it is difficult to see the display in direct sunlight. I tried the newer Hudly Wireless and found that opaque screen made focus transitions very uncomfortable. Therefore, I have a new Hudly Wireless on the shelf gathering dust if anyone wants to try it.

Ron B
 
Rob - if you wanted to liquidate that Hudly I might be interested... i have GRT equipment so feeding the Hudly data is relatively easy for me.
Thanks for the offer... I'd actually prefer to keep it for now, and put it to use when the hardware is available to drive it... GRT is a consideration for a panel upgrade for me. I have used it in the airplane and am happy with how it works, it's just a matter of finding the right input for it now.
 
There may be another decent option out there now, which will also work with the GRT units, namely the Hudway. Like the Hudly Classic, it uses a projector and curved combiner screen, which gets around some of the drawbacks of the Hudly Wireless flat screen. Like the Wireless, however, it is a single compact unit that sits on the dash or glareshield unlike the Classic which needs to have the combiner and projector mounted separately on the windscreen. Seems like it may have the main advantages of each system while avoiding their drawbacks.

I emailed GRT to ask if they have tested it, and was told that Greg has tried it and that "it worked great in a test environment". Not sure what that means, exactly, but it sounds promising. Apparently somewhat limited in the devices it can work with, but may be a good option. If I ever finish installing my HX, I think it's the unit I would try myself.
 
There may be another decent option out there now, which will also work with the GRT units, namely the Hudway. Like the Hudly Classic, it uses a projector and curved combiner screen, which gets around some of the drawbacks of the Hudly Wireless flat screen. Like the Wireless, however, it is a single compact unit that sits on the dash or glareshield unlike the Classic which needs to have the combiner and projector mounted separately on the windscreen. Seems like it may have the main advantages of each system while avoiding their drawbacks.

I emailed GRT to ask if they have tested it, and was told that Greg has tried it and that "it worked great in a test environment". Not sure what that means, exactly, but it sounds promising. Apparently somewhat limited in the devices it can work with, but may be a good option. If I ever finish installing my HX, I think it's the unit I would try myself.

Do you have a link to this device? When I google it I get a phone based hud.....

Edit...

I found it I think. It’s called the Hudway Cast? To bad it does not seem to have a HDMI input.
 
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Current GitHub HUD projects

Snowflake, using the Stratux as a data source for our HUD project seems to be a very doable thing. While were starting off focusing on using current main EFIS systems as the primary data source over RS232 the Raspberry Pi has a wifi system built in so connecting into the Stratux as a serial data source can be done. Yes it would be possible to merge data sources from WiFi and RS 232.

The following HUD project we found on GitHub had one Stratux focused project.

https://github.com/JohnMarzulli/StratuxHud/blob/master/readme.md

Tron
 
Snowflake, using the Stratux as a data source for our HUD project seems to be a very doable thing. While were starting off focusing on using current main EFIS systems as the primary data source over RS232 the Raspberry Pi has a wifi system built in so connecting into the Stratux as a serial data source can be done. Yes it would be possible to merge data sources from WiFi and RS 232.
Just so I understand: Your project would be Pi-based as well, would connect over WiFi to a Stratux, and then *your* Pi would connect to the Hudly with HDMI? I like it. It would be great if the Stratux functionality could be rolled into your Pi as well, reducing the need to only one device, but even what you have in mind is good.

The following HUD project we found on GitHub had one Stratux focused project.

https://github.com/JohnMarzulli/StratuxHud/blob/master/readme.md
Thanks, i'll check that out!
 
Caution; a bit of thread drift...

I like the idea of an inexpensive HUD, but if it uses data from something like a Stratux, etc, has the Stratux sensor suite been upgraded to include actual air data yet? Or are the gyros, accelerometers, etc and the software good enough to not need the air data?

Charlie
 
TCO to add the Stratux GPS + AHRS HW to the BOM is about $35, retail (Amazon) and will fit inside the enclosure. I think that's a more viable solution than bringing in the wifi and code to support the Stratu[sx] or other gdl90 data stream. With the GPS and AHRS onboard the HUD could be portable and plug and play and not dependent on any other data sources.

Although the Stratux's microservice design could be used with this HUD to completely abstract out the data source or even support multiple sources with a failure protocol. It would prioritize: GPS Navigator > EFIS > (onboard/wifi GDL90)
 
Sorry; TCO?

I know some versions of the stratux have an AHRS, but I haven't seen pitot & static ports on one, though. Have I missed them?

Thanks,

Charlie
 
Sorry; TCO?

I know some versions of the stratux have an AHRS, but I haven't seen pitot & static ports on one, though. Have I missed them?

Thanks,

Charlie

TCO = total cost of ownership

No pitot static system on a Stratux that i know of. That info would need to come from the EFIS, if available.
 
I know some versions of the stratux have an AHRS, but I haven't seen pitot & static ports on one, though. Have I missed them?
I haven't seen a proper pitot/static hookup for a Stratux either, but I believe the AHRS board for the Stratux does have a barometric pressure sensor... So it's at least possible.

Still, the AHRS along with GPS speed and altitude would be great.
 
I use the Hudly Classic in my plane and it works very well, except it is difficult to see the display in direct sunlight. I tried the newer Hudly Wireless and found that opaque screen made focus transitions very uncomfortable. Therefore, I have a new Hudly Wireless on the shelf gathering dust if anyone wants to try it.

Ron B

Hello,
I have a new Hudly Classic HUD and before installing it on my RV-6 I tested it with an Android Stick Computer. Everything works fine but after 60 seconds the projector turns off. Could not find a solution in the settings, Hudly did not respond to my request on this problem and they no longer sell the Classic HUD. Have you encountered this kind of problem with the projector of your Hudly Classic? Thank you and happy new years les réglages, Hudly ne répond pas à ma demande sur ce problème et ils ne vendent plus le Classic HUD.
Avez vous rencontré ce genre de problème avec le projecteur de votre Hudly Classic ?
Thank you and Happy new year
Christian Motto
 
I use the Hudly Classic in my plane and it works very well, except it is difficult to see the display in direct sunlight. I tried the newer Hudly Wireless and found that opaque screen made focus transitions very uncomfortable. Therefore, I have a new Hudly Wireless on the shelf gathering dust if anyone wants to try it.

Ron B

Hello Ron77,
I received Hudly Classic from GRT last year, to use in my RV-6 with Sport EX EFIS. It's work, but,
My question, I have power lost after 1 minute using 12V, I tried another projector from Hudly, and after 1 minute the power is lost with a little noise (Click) .
Hudly do not answer to my question, and GRT Avionics have no answer.
Did you have such problem ?
Sorry for my bad english, I am in France.
Christian Motto
( RV-6 23853, and before RV-6A F-PVAC )
 
@Christian, I have a Hudly classic as well that i've used in my RV-6, I drove it using my Stratux for AHRS data. It worked just fine for me, but i've decided not to continue with it as it is too large a lump on the glareshield for my liking.
 
Hi Christian - I have also been flying the Hudly in my RV-8 since GRT first sent me one a few years back, and haven’t had the powering-off problem you’re reporting. I wonder if it is losing connectivity and then turning itself off because it doesn’t have a signal. If mine loses connectivity, it just displays its welcome message - but maybe there was a firmware change in later models that makes it go blank after it loses data input.

Just guessing here!

Paul
 
Ah! Yes, Paul's post reminded me. I used mine in the RV-6 with a direct connection (HDMI Cable) to the Stratux. When I decided that wasn't a practical solution, I put it in my car for a while using the original wireless connection. I found it almost unusable. We have city-wide WiFi here, and my phone will hop from wireless hotspot to hotspot as I drive. Coverage isn't 100%, but it's enough to ping for mail once in a while without using the Cell data.

If you're connected to the Hudly with WiFi, you have no internet connection... Which means your phone will want to keep looking for one as you move. When it finds one, it'll switch to it, breaking the connection to the Hudly, and the Hudly goes back to it's connection screen (mostly black, which may look like it's "off", or maybe as Paul says they've changed the way that works).

To fix this you need to find a way to change the wireless settings so it would maintain a WiFi connection and a Cell data connection at the same time.
 
@Christian, I have a Hudly classic as well that i've used in my RV-6, I drove it using my Stratux for AHRS data. It worked just fine for me, but i've decided not to continue with it as it is too large a lump on the glareshield for my liking.

Hello Rob and Paul, and thank you for your answers.
I use what GRT sold me but they didn't have the power cables so I fitted a mini USB cable on the projector and it works.
I am not using a phone but an Android Mini PC 'MK 809V_4K' sold by GRT.
Everything works but cut after 60 seconds.
If I try to connect the Android Mini PC receiving the PFD information from GRT's Sport EX EFIS to my television and not to the HUDLY Projector, it works perfectly and no power cut after 60 seconds.
So the problem is internal to the projector and we are looking ...
Thank you again, first flight planned for my RV-6 Nb 23853 (F-PVAC ° before summer 2021 normally, I will send photos.
 
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