I took my prototype airspeed indicator on two wingsuit jumps yesterday and got good and bad results. This gives me direction for the future direction of the project. The good news is that the pitot tube placed at the wingtip produced what I think are valid results, and I will forge ahead.
My project involved me connecting several sensors via I2C and a GPS unit via serial input, all coordinated by an Arduino Nano. I did the coding, which made gooduse of existing librairies.
If I were to consider bringing such a product to the (admittedly small) skydiving retail marketplace, to whom would I bring the idea to for proper electronics vetting, and improvement of the idea. Where does one find such a person? I have not considered any circuit issues. I have the Arduino connected to a cell phone power bank, and the SD card stores the data as it should.
I do have the issue of outputting the speed for use by the wingsuit pilot; the LCD idea did not work. I am considering LED strip lighting as a means of indicating when the pilot is near or at the desired speed, as wel as an audible indicator.
Curious_John:
If I were to consider bringing such a product to the (admittedly small) skydiving retail marketplace, to whom would I bring the idea to for proper electronics vetting, and improvement of the idea. Where does one find such a person?
Do you mean that before going on sale your product would need to be approved by the Aviation Safety Authority in your country? If so that would be a very big undertaking - and very expensive, I suspect.
Hi Robin, no safety issues involved. I should have clarified, it's an airspeed indicator for wingsuiters. I'm an airline pilot in my regular job so I know about that stuff.
I'm more looking for guidance on what type of professional one approaches to further a design. Maybe it's as easy as contacting a professor/instructor at a technical college.
I think my idea has legs, but perhaps the cost would outweigh what I could sell it for. I'd just like to find out how to proceed.
I used the MS4525DO. I purchased a couple 5525's but I didn't have time to figure out the code, and I also didn't like the orienation of the connections (vertical, versus horizontal on the 4525).
Here are the Indicated Airspeed results, at 1 per second over a 2 and a half minute flight. I will be recording temperature and static air pressure on future flights in order to determine True Air Speed, but really, I am primarily interested in Indicated (Calibrated) Air Speed for performance reasons. The units are Knots (nautical miles per hour).
Curious_John:
I'm more looking for guidance on what type of professional one approaches to further a design. Maybe it's as easy as contacting a professor/instructor at a technical college.
If you are thinking of developing a commercial product then many Governments have agencies that provide advice for start-up businesses. If there is an agency like that where you live they may be able to point you in the right direction and probably won't charge, at least for initial advice.
Technical colleges are certainly another option. A student doing a senior project might be interested in helping with supervision from a professor.
If all you need is some advice about an electronic circuit then you may be able to get all you need from the internet in a suitable Forum.
Curious_John:
Hi Robin, no safety issues involved. I should have clarified, it's an airspeed indicator for wingsuiters. I'm an airline pilot in my regular job so I know about that stuff.
So if the airspeed indiucator provides complete nonsense thats not a problem ?
Umm, the airspeed sensor is actually quite accurate. I had bad data from a helmet mounted pitot tube, but the wingtip probe seems to align quite nicely with a GPS unit I was wearing. I'll know more when I do the next series of tests wher I will record static air pressure and air temperature, which will enable True Airspeed (TAS) calculation.
Indicated (IAS) airspeed that I am reading with the sensor and code, is basically the pressure that the wing feels, it's the same reading you'll see on an airplane's airspeed indicator.
For time, speed, and distance calculations, TAS is necessary. But for determing the speed at which an aircraft or wingsuiter will glide the furthest, IAS is the info needed.
It all depends on what country you are in. Most electronic devices need CE certifacition in Europe of FCC certification in the US. Other countries have their own regulatory bodies. Thesing should take about half a day inan authorised test lab the rate is normally about £400 per half day.
I do design work like for folks for hire. Not the certification part tho.
I'm working on an Angle of Attack indicator board, to be fed from a Dynon dual input Pitot to feed airpressure into, mount it on an inspection panel on my Cardinal's wing for testing and not interfere with any of my existing systems.
Here's what it looks like so far.
CrossRoads:
I do design work like for folks for hire. Not the certification part tho.
I'm working on an Angle of Attack indicator board, to be fed from a Dynon dual input Pitot to feed airpressure into, mount it on an inspection panel on my Cardinal's wing for testing and not interfere with any of my existing systems.
Here's what it looks like so far.
I had a Dynon D-10/10A in my RV-6A that I just sold. What you are doing looks to be what I am going to need done. I'm just messily soldering wires and leads and using hot glue guns and Gorilla tape to keep it all together. Once I get a little more visibility about precisely what the program specs are, might I contact you? No promises, I'm just a guy with time on my hands and a desire for a product. But I realize the YouTube videos alone won't put a professional product on the market.
BTW, the Cardinal is a nice airplane, from the few flights I had in one years ago, just not great fro skydiving exits..no strut!
Curious_John:
Umm, the airspeed sensor is actually quite accurate.
Whoa.. Hold on a moment ... Slam on the dive brakes ....
I don't think you can claim any more than that you have one device that has so far worked quite accurately while it has been in your tender care
If the data from the device is more valuable to a user than a photo of Mickey Mouse then the product needs to be proven to be very reliable in all sorts of adverse circumstances and in the hands of complete fools. Without that reliability it is just the equivalent of a toy in a Christmas Cracker.
And that's why i why I ill be taking it back down for a series of test flights in the new year as well as using it in my wingsuit competitions starting iwoth the championships in January. I have tested the 4525's differential psi readings verus a commerically available very precise digital manometer, and the 4525 is very accurate as well. Since my coding seems to be correct, (the psi reading is proof of that), then the next error would be my converion to knot from differential psi. That has been checked over and over and it seems correct.
The next error would be position error, created by the position of the pitot tube with it's toal pressure and static pressure ports. Because a wingsuiter can move his/her arms, this one is open to fluctuation in readings. But looking at the results, there are periods of time when I maintained the same speed, subject to rounding for 9 seconds, this tells me that the data seems consistent. Same with the acceleration and deceleration, it is smooth and not jumpy.
Time will tell, but the initial results are VERY promising. If I can make the podium in the championships in California in January, that would be a great testimonial and worth more than a photo of Mickey.
I was not trying to criticize what you have achieved. However there is a gap like the Grand Canyon between a prototype and a commercial product that can be used reliably by people who know nothing about the system and care less. Especially if you risk being sued by the dependents of someone who gets killed while using your product - even if the accident has nothing at all to do with your product.
No worries, I appreciate any and all feedback. Skydiving is a pursuit in which all participants sign numerous waivers at evry step along the way. An airspeed indicating system would be no different. You use it, you sign away any and all rights to sue. The market for such a device is very small and the users will be a very specialized group of people.
Besides, in a wingsuit, no one is going to die or get injured because of an incorrect indication. You are very cognizant of your speed. Well, most of us are (watch 2 minute video here: I flew my wingsuit into trees… and woke up in a hospital! – Topgunbase). The more likely problem might be the pitot tube creating a snag hazard with the parachute lines. But then, skydivers mount GoPro cameras all over their bodies creating snag hazards and no one, to my knowledge, as successfully sued GoPro for creating such a hazard with their product.
