top of page

The Energy Display Matures

Welcome Kacy and Paul!

One of the cool things about this project is that everyone working on it is a volunteer. We do this because we find it to be a neat challenge and we enjoy it. With all of the talent we've got, we've made some great progress for a low-budget, "no rush" ad hoc project. One area we've always been short in is proper data analysis. This is the critical part of flight test that verifies that we have, in fact, got the physics right. In the aviation professional world, the folks that do this best are highly trained flight test engineers. When I was in the USAF, there was a whole bunch of talented folks that could always compensate for a history major stick monkey like yours truly and keep me coloring between the lines. Recently, I put a shameless want ad on Van's Air Force to see if anyone in the VAF family might be interested in helping us out with this vital task. Well, lo and behold, a couple of super talented folks actually stepped up to the plate! Not only are they really good at what they do, they know enough small words and have the patience to effectively communicate with me, Blue 4. Huge. Kacy and Paul are building an RV-7 (dope), and I know I speak for the whole team when I say how happy we are to have the help. Welcome :)

The Energy Display Matures

We are busy doing analysis of overall angle of attack accuracy and performance as the software matures. We've got two big "to dos" at the moment: developing a working calibration wizard that will step the pilot through a simplified calibration procedure; and measuring beta with the on-board IMU (and developing an alpha correction algorithm). We also want to develop a dynamic AOA based maneuvering speed cue, as we think that has significant utility for improving the quality of the energy display.

Meanwhile, Vern Little has done some great work adapting the M5 Stack display. The M5 is an inexpensive (about $45) computer prototyping device. For us non-tech savvy folks it's a bit like an Arduino--an all-purpose device that has some processing capability with the addition of a neat little sunlight readable visual display with three function buttons.

While it's practical to use the M5 stack as it's supplied by the manufacturer, Vern has developed a custom power board (about $30) that accepts standard 12v DC power and back shell that makes it much more friendly for mounting in an airplane with a minimum number of wires and provides a standard AN screw and nut "hard point" to mount to. And a shout out to Rob Prior for assisting by designing some nifty, inexpensive printed mounts for the display. We'd estimate that all in with wiring, mounts, custom power board and the M5 stack itself, the energy display will be about 100 bones. It's not required--the heart of the ONSPEED hardware is the aural warning capability; but it can be a nice addition for folks that want the redundancy of a visual display (or just simply prefer visual information over audio). While we still think the ultimate visual display is a proper HUD, we've also learned how expensive that can be. We also think the energy display is the perfect "back seat" instrument--all of the energy information you need to fly the airplane if you are giving dual instruction or just flying from the trunk.

Fig 1. Standard M5 Stack Back, outside
Fig 2. Standard M5 Stack Back, inside

Fig 3. Vern's Custom Power Board, inside

Fig 4. Vern's Custom Power Board, outside
Fig 5. Display Components

Fig 6. Panel Display Mount Option

Fig 7. 3 1/8 Instrument Display Mount

Fig 8. Hand-crafted PVC Clip on Mount (e.g., RV-8 rear cockpit)

The current plan is to adapt an existing GoPro mount in the RV-4 to allow me to place the instrument right in front of my skull in a "head's up" position above the canopy rail (ala F-16, there is no canopy bow in the RV-4).

Fig 9. "Head's Up" RV-4 Imagineering

Fig 10. Standard GoPro Mount Inside the Canopy Skirt

Plug for Using the Forum and Guest Blogs

We are always happy to answer emails, texts etc.; but just wanted to put a plug in for using the forum technical discussion. Recently, our "solder team" completed a number of V3 boxes in the field. They not only built the hardware; but they helped us QC builder's instructions, parts lists, schematics and software loading/programming procedures. The results are published on our GitHub site. We have a few excellent email trains with lots of great information, including sharing surplus parts etc., but unfortunately that conversation isn't available for lurkers or folks that are interested in the sausage making process. The best place for that type of discussion is the Forum section of this site. Forum posts are a great way to go "giant voice" with information and lessons learned. So, the request is that if you have a technical question or information, please post it on the Forum. Our team members get text and email notifications when folks participate in the Forum, so the response from us will be just as fast as an email, etc.

In the same vein, we are uber happy to accept guest blogs from anyone, any time. You can email me directly at or with pictures and text, I'll get it posted for you. If you've built or experimented with any of our hardware or software (or have a cool related story), please share with the community. Our whole purpose is "self help," and the more, the merrier! That way we don't always have to listen to Vac, which my wife will attest isn't always a brilliant way to spend time...

211 views1 comment

Recent Posts

See All

1 Comment

Carlos Rodz
Carlos Rodz
Jun 15, 2020

The cool thing about this is that I can install one on the dash and if I lost audio I have this as backup PLUS the GIB will have all the info they need to land if needed without having to stretch their neck to see my instruments over my shoulder.

bottom of page