A useful instrument to have

On a sunny day (Sun, 24 Sep 2017 18:49:34 GMT) it happened Steve Wilson wrote in :

Against a big adversery nothing is secret. In my hacker days I cracked TV smartcards with PIC what was it 16F84 or something.. It has code protection, but only so much. Of course since it has been made illegal I play by the rules... no longer do these things. The bigger guys just open the package and probe the chip. There was an Israeli company that was payed by Murdoch to crack the competitions TV Viaccess system and publised the C code on Usenet. History, 24 hours later I had that C code adapted running and working in Linux. A bit later I had it in FPGA as a brute force key cracker.

What was it alt.satellite.tv.crypt??? 17 years ago, group still exists..

NOTHING will remain secret.

Now for those US lauch codes 000000000000

Presumably that's to prevent over-current during a full-on stall. I would /imagine/ there's a range between that and normal operation where the protection doesn't prevent significantly increased torque.

But who knows what's in any individual drone.

FYI, I got my information from RC modellers, one of whom had a model ME-262 where the "jet" engines were electric motors running at 22krpm!

I presume you are aware of the IDSC at ETH Zurich videos; most eye (and ball (but not eyeball)) catching:

The usual solution is to add shrouds to the props. Here's my Walkera QR X350 (not Pro) clone, with the added shrouds: I spent the previous winter indoors flying this drone around the house. Before I added the shrouds, I would break a propeller every few days usually when I flew it into a wall. After adding the shrouds, I still tend to fly into walls, but the propellers don't break. Progress, I guess.

I'm not sure if that's true. My guess(tm) is that unshrouded, large diameter horizontal quadcopter propellers tend to approach people's eyes with the props perpendicular to the face. That gives it direct access to the victims eye, without any protection from the brow ridge or nose. However, RC model aircraft approach with the props parallel to face, where the odds of the props taking a piece out of the nose or forehead are better than hitting the eyes. The props are also much smaller for RC planes. There are 4 props on a drone and only one or two on an RC model airplane giving a higher probability of being hit by something spinning. Lastly, RC model airplane pilots are not nearly as insane as the typical drone pilot.

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Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

On a sunny day (Sun, 24 Sep 2017 20:27:57 +0100) it happened Tom Gardner wrote in :

Agreed.

Ah yes, those are awful speeds! These drone motors are not so fast.

I am absolutely amazed, had not seen those. Yes, with that ring sort of thing to make it catch the ball... is what I had in mind. I see they use overhead cameras, and a big computer..

Some years ago I did this, with servos, from a normal webcam with NTSC output:

As the setup sees a high brightness object (IR or white ball whatever) it steers the x, y servos immediately to point to it, so it is - and stays in the center of the image (no escape possible). With the drone I need no servos, and the camera is already in it. Since I already wrote that soft in a simple PIC (no big computer, no weight, no power) I think (plenty of code space left) I can get it to position a ring so it is under the falling ball. Makes playing ball easier ;-)

Hmmmm. From the link Jeff posted:

"Confused by Bright Shiny Objects? Infrared thermometers have good accuracy when measuring most objects, but shiny, reflective surfaces can be a challenge. You should be especially wary when measuring the temperature of shiny metal objects, but even reflections off of glossy paint can affect accuracy. Putting a piece of non-reflective tape (such as electrical tape) over the shiny surface or applying some flat paint gives you a target from which you can get a better measurement."

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I knew that!

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John Larkin         Highland Technology, Inc 

lunatic fringe electronics

That's common sense. Unfortunately common sense isn't common :(

True, but I don't think that affects the point about torque. Additionally, I doubt much torque is needed slice an eyeball.

Drone pilots aren't so much insane as thoughtless, ignorant, and not given a clue by long-time members of RC clubs.

Plus the drones are marketed as fun toys for the boys, and that sets expectations. Yes, I would like to see drone manufacturers/distributors/sellers in court to justify that marketing.

On Sunday, September 24, 2017 at 11:22:33 AM UTC-7, Tom Gardner wrote: ..._1448629861320.jpg

Not necessarily true with the sensorless brushless motors that are often used on drones or model aircraft.

They rely upon the back-emf induced in the windings for commutation - there isn't any until they are rotating so they may just twitch when starting util they have enough speed to give reliable position sensing.

kevin

I use one of these:

Anything that adds weight or cost is considered a bad thing. While shrouds add some safety, they also add weight. Ducted fans would be better, where the added lift compensates for the added weight. That's great if all you want is more flight time or carrying a bigger camera. However, I'm told that ducted fan quadcopters are as maneuverable as the average elephant, and are totally unsuitable for racing and acrobatics, unless the angle of each ducted fan is individually controllable:

Ok, you're right. I was just trying to point out that the probability of getting hurt by a propeller is much higher with a non-shrouded quadcopter than with an electric RC model airplane. Stall torque is the equivalent of starting torque as both are measured at zero rpm and a the highest motor current: "Since the motor is consuming the highest possible electrical power, it also outputs the highest possible mechanical power (Stall Torque) while stalling."

Also true. During college, I had a part time job helping to put price tags on lost or mangled body parts for insurance purposes. I think I'll pass on evaluating the relationship of torque to damage done.

It's like that with any new invention. The early adopters are usually quite safe and sane as they probably built their own toys and understand how they act. Later, the great unwashed masses arrive, and demonstrate evolution in action. I don't know of ANY machine that was demonstratively safe upon first introduction.

That could be done, but methinks first establishing minimal safety and design standards will provide the courts with guidelines for what might be considered an unsafe product. Also, you might find it difficult to sue a manufacturer in China.

It might also be useful to do a better job of design and programming: "Drone accidents mostly caused by technical problems, not operator error, research shows" My drone has gone out of control several times for various dumb reasons, which I suspect was caused by bad controller programming or difficulties handling undefined states.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

I probably asked this in the wrong forum, but I'm hoping security has improved over the years.

It is probably difficult to probe 512k of encrypted memory.

Brute force cracking would have little chance against a 64-bit password from Steve Gibson:

----------------------------------------------------------------------- Generating long, high-quality random passwords is not simple. So here is some totally random raw material, generated just for YOU, to start with.

Every time this page is displayed, our server generates a unique set of custom, high quality, cryptographic-strength password strings which are safe for you to use:

64 random hexadecimal characters (0-9 and A-F): C888DD4B79E8DE07EEE1F514C1E4C935B98EC97010F577A77F9E5EAD35150510 63 random printable ASCII characters: r\t6rE1%_o?czSf2uBFiHrCW2nK93v/Tvdc[

That ia not 64 bits. It is more like 64 * 8 = 512 bits, but the MSB is always zero. Still pretty good for our needs.

I don't care. They don't know where I am going to use the passwords, and they are all different for each site.

Gibson uses https, so as far as we know, nobody can snoop.

The NSA probably could log the passwords, but what is the point? They don't know if I modify them, which I do automatically, or where they are going to be used. All you need to do is change one bit, and it's a completely different password.

Generating random numbers is hard.

It has. For nuclear devices, it's called a PAL (Permissive Action Link): Currently, the maximum code length is 12 digits.

Transmitting the code is part of OPLAN 8010-12:

More to worry about:

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

A digit is 0 to 9, right?

2^(12*10) = 1.32922799578e+36

Should be OK. How do I put that in my PIC?

Insane. You don't know where the bomb will be detonated. What point is that?

sometimes, depends which MCU you pick.

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On a sunny day (Mon, 25 Sep 2017 01:36:20 GMT) it happened Steve Wilson wrote in :

On a sunny day (Sun, 24 Sep 2017 23:10:17 +0100) it happened Tom Gardner wrote in :

Some countries now require licensing, you need a drone 'flying license'. I guess in the old day with the first cars the problem was similar. Suing the manufactures is no solution. Training the people is. Accidents still happen.

When self driving card happen in quantity things may become worse again. AI has no human aspect of give and take, courtesy etc, in that context Musk is right, AI is very dangerous.

Yes, but some experimenters can concentrate too much on how things work, and don't seem to consider how things might fail.

There are people like that in the local hackspace :( I've quietly warned one that if I see his creation (~2' across, 4*30cm props) moving under its own power, I'll pick up a hammer and...

Just a little! Hence my including manufacturers and distributors.

I see little likelyhood of that happening here; it has long been legal to sell things that are illegal to use. I first came across that as a kid, w.r.t. airband radio receivers.

That /seems/ to have looked at accidents caused during relatively responsible operation. That I can believe.

More concerning to me is the grossly irresponsible behaviour, in the same vein as pointing lasers at aircraft, or shooting up passing streetcars. (The latter happened to me as an infant in Pittsburgh; I was showered with glass and my parents decided they didn't want to live in the USA).