Aircraft Angle of Attack Indicator

[rq3]

My first Picaxe project - a programmable angle of attack indicator with automatic LED brightness control.

Link to a video below ...

http://www.youtube.com/watch?v=x4cd2GfgDPI&feature=colike

 

[hippy]

Excellent project and a professionally put together product - I guess it has to be for use with aircraft !

Any chance of circuits or code which would help inspire other PICAXE users ?

 

[rq3]

Excellent project and a professionally put together product - I guess it has to be for use with aircraft !

Any chance of circuits or code which would help inspire other PICAXE users ?

Thanks hippy. I'm hesitant to post specifics for commercial reasons, but I'll be happy to answer specific questions if I can.

 

[techElder]

My question is ... why do you post to advertise your commercial product on a forum built mainly for sharing information, claim to have built it out of a PICAXE and yet provide nothing to share like others here have with their commercial products?

One answer might be obvious and would normally require moderation, but you seem to have escaped that fate. Others have not for much less egregious posts.

 

[westaust55]

My first Picaxe project - a programmable angle of attack indicator with automatic LED brightness control.

The "PICS" link on the website includes a link to a YouTube video of the device in action.

What happened to projects 1 and 2 prior to Christmas 2011?
http://www.picaxeforum.co.uk/showthread.php?20092-Generator-controller-code&p=190723#post190723

From the website:
The General Technics CYA-100 will survive, operate, or be destroyed under these conditions:

seems rather terminal considering most aspects indicate either "Not susceptible" or "no effect".

What part does the PICAXE play in the overall project?

I'm hesitant to post specifics for commercial reasons, but I'll be happy to answer specific questions if I can.

specific questions:
1 can we see the PICAXE program code
2. can we see a schematic diagram
3. which PICAXE chip is used
4. what is the make and model of the sensor used
5. what is the comms protocol.

Tentatively a good project but with only a link as given, I reiterate comments I have made in the past with respect to links to you-tube and similar.
A brag with no substance that might allow other students and hobbyists who are the mainstay of this forum to emulate the project.

The by-line for the PICAXE Forum Finished Projects section is:

Show off and share your completed project with the PICAXE community!

 

[hippy]

It's a reasonable concern that publishing details of a commercial product effectively open sources it, may lead to people building their own and taking away income.

In practice a commercial product is often far more than just knowing the how to. That one could build it oneself doesn't mean potential customers can or even want to. I doubt many aircraft owners would prefer a wooden stick, a pot and a playing card version to the commercial product here. Those that would are probably not potential purchasers anyway. The value is in the engineering, testing and proven design.

Where there may be some 'proprietary magic' in the code I don't think there'd be any objection to noting that, turning routines containing clever calculation and the like into empty sections of code just describing what it does rather giving the details. At least the framework is there for others to see.

For 'commercial copiers' where a product is more hardware than software it's unlikely that not having the code will hold them back, nor will having it give them any real advantage, especially if any really clever stuff is missing.

 

[techElder]

Otherwise, there's only one reason to post a link to a commercial product ... FREE ADVERTISING ON A POPULAR FORUM.

See how nice these folks are? Your link is still visible.

Sorry, it just gets my goat ...

 

[hippy]

I have taken the liberty of replacing the original link to the website in post #1 with a direct link to video.

 

[Paix]

Thanks Hippy, that made a lot more sense than the web page did, where it was far from obvious what we were looking at.

 

[rq3]

What happened to projects 1 and 2 prior to Christmas 2011?
http://www.picaxeforum.co.uk/showthread.php?20092-Generator-controller-code&p=190723#post190723

From the website:
The General Technics CYA-100 will survive, operate, or be destroyed under these conditions:

seems rather terminal considering most aspects indicate either "Not susceptible" or "no effect".

What part does the PICAXE play in the overall project?



specific questions:
1 can we see the PICAXE program code
2. can we see a schematic diagram
3. which PICAXE chip is used
4. what is the make and model of the sensor used
5. what is the comms protocol.

Tentatively a good project but with only a link as given, I reiterate comments I have made in the past with respect to links to you-tube and similar.
A brag with no substance that might allow other students and hobbyists who are the mainstay of this forum to emulate the project.

The by-line for the PICAXE Forum Finished Projects section is:

I guess my definition of "share" doesn't include "completely divulge".

In this case the Picaxe is responsible for:
1) sensor A/D conversion
2) Power on self test of display and its own memory status
3) programmable storage and processing of the sensor output
4) monitoring LED photodiode voltage, and using the result to automatically adjust the display brightness
5) drive the display

The tech specs include "will be destroyed" because carbon fiber and urethane are flammable.


Specific answers:
1) No
2) No, the schematic involves components (particularly as regards driving LEDs) that apparently even Microchip is not aware of
3) 20M2
4) Melexis 90316
5) Analog. The sensor and the picaxe share a common power supply. The sensor wire run can be as long as 80 feet in a very noisy environment. Using a common supply with A/D conversion keeps the picaxe response ratiometric in extreme environments.

 

[rq3]

Otherwise, there's only one reason to post a link to a commercial product ... FREE ADVERTISING ON A POPULAR FORUM.

See how nice these folks are? Your link is still visible.

Sorry, it just gets my goat ...

How...bizarre. Above and beyond TechEds' altruistic motives, I have always thought they are in this business to make money. If I were spamming grossly unrelated products on a forum SPONSORED BY THE RETAILER of an integrated circuit, I would agree with you. I have read all of the forum threads, and occasionally a post asks if there are commercial products which INCORPORATE TechEd Picaxes. There are, and mine is one.

Visiting my website gives some info on how well a Picaxe can survive in a fairly strenuous environment. In fact, recently there was a thread regarding the use of Picaxe in an orbiting satellite. I hope the information on my site gives the gentleman a bit of faith that his device may survive. If it doesn't, it provides him a means to contact me.

No one is forcing you to click on the "buy" link.

If a major aircraft manufacturer were to decide to incorporate my product in all of their planes, I would bend over backwards to promote them, as that would promote me, and THAT would promote TechEd.

But of course, there are always those who feel that "I don't like it, so you can't see it" is the order of the day.

 

[rq3]

I have taken the liberty of replacing the original link to the website in post #1 with a direct link to video.

hippy, that is one of the most diplomatic responses I have ever seen from a moderator since 1978. Seriously.

 

[srnet]

2) Power on self test of display and its own memory status

That caught my eye, how exactly does a PICAXE check its own 'memory status' ?

 

[rq3]

That caught my eye, how exactly does a PICAXE check its own 'memory status' ?

At power on, the picaxe checks for two items:
1) a pin pulled to ground (switch closure)
2) data (any data) in a memory location

If the pin is low, it erases the existing data, and then writes a new A/D word into memory when the switch is released.

If the pin is not low, the picaxe goes into LED test (strobes through all LEDs from minimum to maximum brightness) and then continues
with the rest of the code.

 

[nick12ab]

At power on, the picaxe checks for two items:
1) a pin pulled to ground (switch closure)
2) data (any data) in a memory location

If the pin is low, it erases the existing data

The PICAXE interpreter erases the memory for you on power-on so this is unnecessary. A better test would be to write some data in patterns (%10101010 then %010101010) and verify it.

TechEd

It's Rev-Ed.

 

[rq3]

The PICAXE interpreter erases the memory for you on power-on so this is unnecessary. A better test would be to write some data in patterns (%10101010 then %010101010) and verify it.



It's Rev-Ed.

I'm referring to "permanent" EEPROM data. I should have made that clear.

Thanks for the Rev-Ed correction!

 

[srnet]

So its some form of calibration routine ?

 

[rq3]

So its some form of calibration routine ?

Exactly. Every aircraft wing has particular angle of attack at which it will stall (stop providing lift). The angles are programmed into the picaxe by the end user for his unique requirements. After that, on power-up, the picaxe looks at the stored words and checks that their values are "reasonable", and also looks for activation of the programming switch.

 

[srnet]

Every aircraft wing has particular angle of attack at which it will stall (stop providing lift)

Sure, but stall speed varies with air density (temperature, altitude etc), so do you compensate for that or are the differences not significant ?

 

[rq3]

Sure, but stall speed varies with air density (temperature, altitude etc), so do you compensate for that or are the differences not significant ?

Stall SPEED varies. Stall angle of attack does not. This measures angle of attack.

 

[srnet]

I was forgetting the basic aerodynamics.

I do only fly model planes, but apart from different reynolds numbers, the principles are the same.

 

[rq3]

I was forgetting the basic aerodynamics.

I do only fly model planes, but apart from different reynolds numbers, the principles are the same.

You're a better man than me. I've never been able to fly an RC plane without burying it.

 

[DakLak]

It's a reasonable concern that publishing details of a commercial product effectively open sources it, may lead to people building their own and taking away income.

Where there may be some 'proprietary magic' in the code I don't think there'd be any objection to noting that, turning routines containing clever calculation and the like into empty sections of code just describing what it does rather giving the details. At least the framework is there for others to see.

For 'commercial copiers' where a product is more hardware than software it's unlikely that not having the code will hold them back, nor will having it give them any real advantage, especially if any really clever stuff is missing.

One of the services the company I work for is resurrecting discontinued PCBs, etc. Some industries, such as the elevator/lift industry, have products that work for years and whose manufacturers fade long before their equipment joins them. Theere is usually no copyright concerns through time or ceased ownership.

Where a replacement board is needed, it is essential a direct copy be made so as to retain the "type approval" for the elevator/lift.

This means copying. Some boards are encapsulated in expoxy or other goo, but they ar easy to copy.

Although located in VietNam, many of our assignments can be completed in-country. We have friendly financial arrangements with local X-ray operators who can easily produce prints of double sided boards. 4-layer are more difficult.

For really tough assignments we simply ship our stuff to China - a couple of days later we get Gerbers back, even for multi-layered boards.

'Analysing' integrated circuits is very similar.

You might have heard of Villeman (spelling?) kits. I know our Chinese 'resuscitator' can turn most of their PCBs with microprocessors around in a day and return them with a software listing alongside everything else.

Removing IC identification is pointless, the X-ray of the die for almost every chip is available and identification is computerised.

So your 'protection' is very low, for the cost of one of your units, a competitor can get a complete breakdown for an additional USD$100-200.

Strategies can be employed to obsfucate information but in the end it is futile.

Patents will protect you from commercial plagiarism so all you are doing is stopping enthusiastic hobbyists from learning.

 

[Paix]

{QUOTE] Stall SPEED varies. Stall angle of attack does not. This measures angle of attack.

@Rq3, I didn't actually know that, but I guess that I understand. As the angle of attack increases beyond the optimal angle for a given wing, the drag increases and the lift decreases until it's all drag and as the lift falls off the effects of positive gravity take over? << rhetorical, but only if I'm correct >>

@DakLlak, Strategies can be employed to obsfucate information but in the end it is futile. That sounds like a statement from The Borg from the StarTrek TV series. "Resistance is futile, all life forms will be assimilated into the collective". It does make hobby electronics seem very tame once the technologists start reverse engineering things with a will.

Your contribution to the thread is indeed an interesting insight into how circuit and device Resuscitation is handled in the real if sometimes alternative world.