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   FlyONSPEED Head Up Display Project
    *Featuring the most cost effective & Highest
      Quality Gen Aviation HUD Available Today*

             The Epic Optix EAGLE 2 HUD
                             Note:  Any HDMI or NTSC/PAL compatible HUD/VIDEO Display can be used.


      Why have a HUD in an Experimental Aircraft?

HUD enhances safety by providing critical flight information in the visual (Heads-Up Outside the Aircraft) pilot environment

•Typical aircraft HUD displays:  

  • Airspeed, Altitude, Attitude (pitch/roll), a Horizon Line, Heading, Vertical Velocity, Angle of Attack, and Slip/Skid indicator

•  Boresight/waterline symbol

•  Flight Path Vector (FPV, also called Velocity Vector)

•  G’s, QNH, Wind Dir/Speed, & OAT

•  Critical Traffic Data > Nearby ADSB Tgt Display Circle (TD Box InWork) 

•  Navigation (CDI/VDI),etc/& Comm Data for Departure, Cruise and Arrival phases of flight

•  Critical Aircraft and Engine Data

•  Our HUD functions now include a Fun "BFM" mode

The OnSpeed HUD Project provides "FREE" User Supported (Shareware) Raspberry Pi HUD Software hosted on GITHUB that supports the Following Experimental Aircraft Avionics Systems:

•Serial data from MGL, Garmin G3x, Dynon Skyview & D100 (GRT Next?)

•WIFI from Stratux, iLevil BOM, iLevil 3, uAvionix Echo/PING UAT, Dual XGPS190, Dynon ADSB wifi, etc.

•Users can use the software As Is or build custom EFIS or HUD screens


1.   Read this Web Page,  and watch the Videos and checkout the Web Links below

2.   Checkout the attached OnSpeed & Epic Optix HUD Briefings below. 

3.   Decide if you want to use OnSpeed Raspberry Pi CPU software or the Epic Optix GDU

4.   To use our Raspberry Pi CPU software create (If you don't have one already) a GitHub account (Free). 

5.   Log into

6.   Download instructions for setting up Rasp-PI (See Shopping List Below)

7.   Perform a “git pull” to download current HUD programs

8.   Select HUD program to use (test with sample HUD Data)

9.   Additional option is to have our team preprogram RaspiPi memory card for your EFIS (Details Below) $20.00

10. If ready to help advance shareware HUD program coordinate with Chris and myself.



HUD OnSpeed Project Discussion


  Our OnSpeed HUD project continues to make progress. We have several flying systems and continue to add new system interfaces.  All Software Interfaces work well (but not all EFIS systems publish the same serial data via RS232).  We currently recommend using the new Raspberry PI 5 micro-processor to support its improved Graphics processing throughput providing 30+ frames/second (FPS).  This FPS rate support multiple streams of real time aircraft wired and WIFI data.  The included picture is the EpicOptix being tested with MGL EFIS data.

  The system basic operation starts by connecting your EFIS or other integrated data source via a RS232 to TTL converter (115k Baud) and/or WIFI to a Raspberry PI 5 (4/8GB) micro-computer.  The Raspberry PI then processes this data using our OnSpeed HUD software and provides the graphics display with HDMI video output.  The Video drives your HUD or a 2nd cockpit display. We have been flight testing with the Epic0ptix HUD for almost two years now.  To accelerate our project EpicOptix has reduced the price of their HUD from $2,000 to $1,500 to help support getting HUD's into the General Aviation community.

  Epic Optix also sells their own proprietary GDU (Graphics Display Unit) as shown in their Oshkosh brief attached below.  This GDU has some advanced software development also using the Eagle 2 HUD but its display is not user changeable, and it currently will not display NAV information to include approach (Lateral/Vertical) guidance even though it can accept ARINC data from several IFR avionics systems.  OnSpeed hopes we can work with Epic Optix to expand their GDU functionality to include this information. 


  Additionally we have several “HUDLY Classic” HUD's which we can sell for $400 (if anybody wants one of these contact me) which I think also work well, but they do not focus at Infinity (actually about 4 to 6 feet) which is a definite limitation.  We have figured out how to feed the HUDLY projector with 12VDC directly bypassing most all the original and cumbersome HUDLY wiring that came with the system originally designed as a Car HUD.


  The inflight HUD picture below was taken in my RV8 using a special iPhone manual infinity focus mode.  And while it does show the HUD display it doesn't show the real HUD as seen by the pilot due to the difficulties in using an electronic camera and an electronic HUD projection that causes continuous horizontal lines to slowly move in a downward motion.  Same as seen by the miniature video camera mounted on the HUD.    None of this can been seen by the pilot.  The pilot see's a very bright (totally sunlight readable) perfectly focused to infinity HUD graphics picture fully across the combining glass, and displayed with all the color graphics as it was designed.  The selected colors are still subject to the background world as viewed through the HUD, so the HUD design must use Colors and Bold Fonts as needed to insure it can be seen in all expected environments.  Additionally the EpicOptix HUD has a fully dimmable Night Mode as you would want from an aircraft quality avionics system.


                                                HUD Project FlyOnSpeed 2023 OSHKOSH Forum Brief 

                                         HUD system Overview, Aircraft System Integration, and RV8 Install Details

                              HUD can be installed and integrated in most Experimental Aircraft



Pictures and links below first show the F18 E/F HUD Screen Symbology we used as the base line for our original HUD design.  Remember our software is built in modules so you can design, modify, or reproduce any type of HUD graphics you want, a B737-800, or F16, or C-130J, or Airbus, or anything.  By modules I mean for each data display (example Airspeed) that you add to (or modify) in your HUD design, you specify size, Font, color, screen location, etc as required by the Python programming language and build your HUD.  The data processing for your specific EFIS is baselined into the software, so as long as your EFIS can provide the data the software has a standard set of data type names that are used in each HUD design.

Brian (one of our original OnSpeed HUD project developers) created a video (several years ago now) using some of his early development F18 SW with actual G3x recorded RS232 flight data played back at 5x normal speed.  This is the Goal of a Create your Own HUD design.  The Black in the video graphic below is actually "CLEAR" in the HUD display projection.




















HUD "Pilot Inflight Selectable KEY" Functions - The 10 Key Function Pad below is mounted on my instrument panel just below the HUD under my Dash Board.  The 10 keys mimic a regular computer keyboards 0 to 9 numeric keys and control our OnSpeed 10 preprogrammed HUD functions.  A brief summary of these 10 functions are as follows. 

"1" DataStart key.  The "1" key starts the HUD data record function.  This function records all the processed data inputs (EFIS/ADSB-WIFI Treaffic/ CDI/VDI Analog) as set up in the HUD Configuration file to a USB memory stich plugged into one of the Raspberry Pi 4 USB ports for post mission download and replay. The "2" DataStop key stops this data record function.  When either key is pressed brief sequential Data Start/Stop & Log File Number will flash on the HUD screen at the key press.

"3" Traffic Circle, this function will show a dimmed 360 degree traffic circle around ownship (max range as set up in the configuration file) with tracked ADSB traffic locations and information, each key press will zoom in a specified distance, after the 3rd "3" key press this function will default back to off.  The "4" BuoyCurLoc key will drop a synthetic target Buoy at you current inflight position, the "5" Buoy+1NM key will drop a buoy at 1 NM if front of your inflight location, and the "6" BuoyClear key will clear these targets.  The "7" DebugCycle key is a function mode that will cycle through and display all the data being processed by the raspberry pi such as CPU data (example such as HUD display FPS (frames per second), aircraft data (pitch/roll/etc), GPS data, engine data, traffic data, etc., and would then cycle back to off (No debug data).  The "8" GunMode key is described below.  The "9" FltPath mode cycles the flight path marker from the default mode that shows both the Flight Path (Azimuth and Elevation) and a Caged Marker that that shows just the centerline Elevation flight path, when the "9" key is pressed the centerline Caged marker is removed and only the Flight Path marker is displayed.  Of note depending on aircraft flight path this marker is often outside of the HUD field of view.  The last "0" TDBox/CDI/VDI key is described below.  All these function keys are software reprogrammable and will change and evolve as the software matures.





HUD "Pilot Inflight Selectable "KeyPad" with Function Identifications



HUD BFM DogFight Mode - New "FUN" Function Feature!  BFM stands for Basic Fighter Maneuvers.

  Pictures below are Video screen shots from the linked BFM test video.  The picture on the left shows the BFM Gun Funnel Mode symbology tracking an Un-Ranged Practice Target.  The Gun Funnel Mode has 3 selectable Aircraft Wing Spans (25/30/35 feet) to help improve unranged target ballistics .  Picture on the right shows the LCOS (4th) mode using ADSB range between Own ship and a cooperative Targets ADSB datalink position.  The Green Arc inside the 50 MiliRadian tracking circle shows Target Range starting at 9k feet with the larger Green Tick mark at the 9 O:Clock position and rotates counterclockwise to show 6k feet range at the 6 O:Clock position and then 3k feet at the 3 O:Clock position and so on.  The Green + Plus symbol is the 2 Deg above aircraft waterline (boresight) simulated Gun aim point.  The cooperative Target N-Number and Target Range (in 100's of feet) is shown in the digital text information below the altitude.  If an ADSB closest target is available (inside 2 NM's) it will be shown in the digital data in all BFM modes.  Currently the Gun Funnel and LCOS displays are not fully Dynamic but will become fully dynamic in a matter of time. 

  The BFM video is some what blurry at times from the aircraft/engine vibration and camera mounting challenges, the vibration is significantly improved from the initial flight testing but will improve more as we continue to work the issues.  You can also see a little Prop Blur when my RV8 (in a turn) passes through the easterly morning Sun (~90 Degs), but the target and HUD graphics remain fully visible, other than flying into the sun the prop blur has been fully removed by using the ND 32 (Neutral Density) filter. 

  The BFM GunMode modes are selected by cycling the "8" GunMode Key (on the 10 key HUD Mode Selector).  Default is BFM off, first '8" key press brings up the Gun Funnel '25' foot Tgt wingspan display mode, the next "8" key press cycles to the 30 foot wingspan mode, next "8" key press cycles to the 35 foot mode, then the next "8" key press cycles to the LCOS (Ranged Target) mode.  The 5th "8" key press press cycles the "GunMode" back to the default BFM Off mode (no BFM display.  This mode is still under test.

See the below Video (from my RV8) at-->

New HUD CDI/VDI Mode - Using an Analog to Digital Chip wired into your NAV units 150 millivolt Analog Needle output the the HUD software can now process and display your CDI needle output (Same as your HSI Display) to show Nav course guidance, and when selected can also display Vertical course guidance (same as your VDI displays).  This mode is selected by cycling the Zero Key (on your 10 key HUD Mode Selector).  Default is CDI off, first '0" key press brings up the CDI needle, 2nd "0" key press adds the VDI Needle to the CDI Needle, 3rd key press cycles back to default CDI/VDI OFF mode (no display.  This mode will also likely see a TD Box function mode added that will put a Box on the HUD display around the nearest target location or an Azimuth location cue at the edge of the HUD to help the pilot with target visual identification help.  Its not known yet if the ADSB target position data rate can accurately support this function.  This mode is still under test.







Screen Shots from the CDI Mode software development 

Other HUD Videos;

A F-18 HUD Description from the DCS Simulator world

Next are Videos including discussion on how the F18 and F16 HUD's work and are different;

First look at the F18C HUD Screen Shot I attached and see what I have pointed out. The F18C has both a Fixed Flight Path Marker, (Centered to Vertical & +/- Horizon) and a True (Ghost) Flight Path Marker as you just observed in your latest HUD Video.


Watch the complete HUD F18C HUD Video on youtube to see what is displayed -->

 Now the same F18C Video + a Night Video with F18 pilot descriptions as to what you are watching

Now look at the Original F18 E/F HUD Design design and watch both the Flt Path Marker and the Ghost Velocity Vector.

You might Ask why are they not aligned (Flight Path Marker and Ghost Velocity Vector). Well its because the Angled Flight Deck Runway is off set from the ship so the Carrier is moving Left to Right as seen by the F18 Pilot. So the F18's True velocity vector has to point where the carrier will be when the F18 hits the deck. As I was trained by some Navy F18 Pilots during my F35 work true flight path (Ghost Velocity Vector) should start out about at the Bridge on final and will slowly merge to the Fixed Flight Path Marker at touchdown.


So the F18 HUD video is really cool.  But what does it mean to a GA Pilot? Were not likely to land on a moving runway,

First watch this F16 Extreme maneuvering HUD Video (Takeoff/Maneuvers/Landing) in a 5 min video.


You can see that the Flight Path Marker stays centered to the Attitude center line (+/- Degs) from the Horizon, but the entire Attitude shifts Left Right following the True Flight Path so the Flight Path Marker is actually shows the true Flight Path but only during moderate or less maneuvering when you can see it.


Then watch this standard military pattern and landing as seen through the F16 HUD video. Not very good quality.


Turkish F16 Landing HUD Video


You can watch the Flight Path Marker and attitude lines stay visible during the entire landing but the pilot has to compensate a little for a cross wind.


Our OnSpeed HUD video software supports all the same functionality but still needs work to align all the flight cues correctly with the outside world as seen through the HUD.


And as before if you are a SW developer and would like to join our GitHub HUD development project please contact Chris or me.



HUD Shopping List (My Recommendations)

So you want a HUD in your plane, what do you need to purchase??  Basic install requires our free HUD software (A ready to redy to run software copy is available below for download or you can load current and previous versions from our Free GitHub Account), HUD display, RS232 to TTL converter chip, and a Raspberry Pi 5 Computer.  Power requirements are 12VDC for the Epic Optix HUD, RS232 chip is 3VDC (supplied from the computer) USB-5VDC for the Pi computer.  To display a CDI/VDI from your NAV unit you will need an Analog to Digital converter chip (power also from the computer).  If you are using a Garmin ADSB system since its ADSB TIS-B WIFI protocol is now proprietary you will need an AVIONIX PING USB receiver (or something similar) for WIFI Traffic input into the HUD computer.  Then for a HUD camera you need the correct Camera that can accept a proper HUD lens and provide the correct video to the recorder.  You will need an "IR" filtered lens to correct for Sunlight camera saturation and one that Zooms correctly & focus to Infinity for the HUD graphics, and a set of ND (Neutral Density Filters) to reduce/eliminate propeller Blur.  I used a 3amp CB (or fuse) for the HUD display, the computer, USB power supply, and for Camera/DVR power.  The HUD has its own power switch, I then installed a Power switch for the Raspberry Pi (allows separate computer reboot if needed), and a separate power switch for the HUD camera and DVR.  All items below I have purchased, tested and used.  I have also purchased many additional items that did not work including cameras, lens, and video recorders.   

Free Raspi5 HUD Software Image Download and Instructions (2.17GB Zipped --> 8GB) (Demo Config File set for G3x & MGL but easily changed)

HUD Software (Option2); E-Mail me for a preloaded SD Memory Card - ($20) Specify EFIS Type

EpicOptix Eagle 2 HUD


Rasp Pi 5 Computer starter kit, case, 110v AC power, SD memory card, (8GB)

Rasp Pi 5 Computer barebones (no case) (4GB)

Rasp Pi 5 Computer Case with Fan and Heat Sinks

Rasp Pi 110VAC  Power Supply  (for Desktop Use)

pingUSB  Dual-Band ADS-B Traffic Receiver (Only Required when Ownship ADSB is a GARMIN WIFI Connection)

Micro HDMI to HDMI Cable (For Plane or desktop testing)

HDMI Splitter (Gnd Testing)

RS232 to TTL Conversion Module (with Data LED) Small and fits inside above bare case) (Beware of cheap Fraud Chips)

10 Key USB Mechanical Mini Keypad

ADS1115 16 Bit 4 Channel Analog to Digital Converter Module (Beware of cheap Fraud ADC Chips)
HUD Camera Foxeer T-Rex Micro 1500TVL Low Latency Super WDR FPV (HUD Camera is Optional)

Foxeer Micro FPV Camera Bracket (Recommend to get 2 or 3)

Extra Power Cable (Recommend to get 2)

25mm 15 Degree Angle IR Board Lens For Camera (Camera comes with Wide Angle Lens That does not work on the HUD)

HUD Camera DVR (HUD DVR is Optional)

Neutral Density Filters for Camera Lens (Required to eliminate Propeller Blur From Video)

12VDC to USB Power Converter

Or a simpler 12VDC to USB Power Converter unit to install



              View the EpicOptix 2022 Oshkosh HUD Briefing

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