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Posted by Jack Crossfire | Dec 23, 2013 @ 06:56 AM | 2,770 Views

A long coveted spruce bending jig begins operation.



It seemed to achieve the desired bend, but it took a whole day to soak & bend the wood. Bent it to 66' expecting it to settle at 45'. It won't retain its shape in wet weather.

While browsing Kickstarter projects, it became clear that most of them were selling self built kits to get a high volume low price. It would require some massive laser cutting. Preparing instructions & replacing all the parts users screw up would be a bitch.

Every day, there is a new idea, a new price point to calculate, a new design change, so it never is finished.
Posted by Jack Crossfire | Dec 21, 2013 @ 11:48 PM | 2,782 Views


A pair of ADXRS450 gyros arrived in the mail bag. Not sure what kind of IMU you're going to build with only 2 gyros, but these are the duck's guts, compared to Invensense.

The gyros you need for the ultimate flying machine are the ADXRS453. They're more expensive, but 700Hz is what physics requires for a quad copter. The ADXRS450 might be useful in a very expensive balancing robot or as a very expensive replacement for a magnetometer.

There are lots of things which might be more expensive than cheap parts, but not more expensive than all the items as a whole. It would certainly be more productive if instead of a variety of cheap parts, that money was concentrated in 1 expensive part. There are brushless gimbal motors, large drivetrains for a large rover, or just rent.
Posted by Jack Crossfire | Dec 20, 2013 @ 10:29 PM | 3,106 Views
Finally discovered more of the Macross universe. Always wished there was more Robotech material as a kid, but even the mighty Silicon Valley TV stations of the 1980's could barely play the syndicated episodes in order.

Kiwipedia revealed there were in fact several movies, from 1987 onward, starting with Do You Remember Love. Do You Remember Love was an alternate retelling of the Macross series. It was never overdubbed. The Japanese voices are more harsh & monochromatic. All the characters sound the same. The animation is a bit more sparkly but still sometimes reverts to still frames. The music is terrible.

It can get boring to repeat the same old plot device of the Zendraeti being horrified at the sight of heterosexuality, Rick & Min Mae being trapped in an unknown part of the ship, the endless Min Mae singing which was nothing more than a plot device but some Japanese writer thought would sell the movie.

It's interesting to compare how reality for the last 30 years followed the Zendraeti. Heterosexuality became the root of all evil for humans. Heaven forbid the fate of the human race depend on men kissing women.

There are some new scenes that would have been fascinating in the 1980's. They're alternate realities where different characters are captured on the enemy ship. Earth is the wasteland while the SDF-1 in space is the civilization. The male & female aliens are enemies with the male aliens siding with the humans.

Destiny intervened to keep Rick with Lisa Hayes a lot sooner in the movie, but she was a lot more feminine in the movie, while being a lot more strictly military in the TV show until the very end.

Minmay definitely became the Jar Jar of this show. At least the idea of singing a song that was 20,000 years old to defeat the enemy was original. They could have given it an alien quality that you would expect from a 20,000 year old song.



Before:


After:




Posted by Jack Crossfire | Dec 20, 2013 @ 06:23 PM | 3,027 Views


The description of Her is almost like a movie that I wished someone would make for many years, but not exactly. The ultimate movie is about a future where the saying "you have to be a friend before you can be a salesman" has been taken to the ultimate level.

Walmart has created sales robots for the purpose of marrying customers. They're better spouses than humans ever could be. People marry the sales robots & spend the rest of their lives with them, in return generating higher profits than Walmart ever dreamed of.

All human interaction has been replaced by computers designed to raise profits to the point of being better at being human than humans. The devil is in creating a conflict & a mcguffin required to theatricize it.

Perhaps a character could find something lacking in the status quo & want a real human, but be all alone. Maybe he falls in love with a real human & his task is to get her to look away from the robots. Maybe the conflict is between him & other people absorbed in a culture that decrees robots are superior & loving a human is insensitive & shallow. There's probably a decent conflict in Her, but no-one in this blog is going to pay the $20 to watch it in theaters.
Posted by Jack Crossfire | Dec 20, 2013 @ 01:57 AM | 3,025 Views
Having no money definitely stimulates the imagination.


As a kid, I only wanted what wouldn't exist for another 30 years: LED TV screens, 4 propeller electric helicopters, a watch which could play video. I rarely wanted anything that was already being produced.


Now I want an exercise coach robot. It autonomously rolls in front of you to pace you, make a timelapse movie & measure position more accurately than a phone, with a really high quality GPS module. It can carry a certain amount of supplies. Because it's not a human transporter, the cost is greatly reduced & it can roll for many miles with inexpensive batteries.

The challenge is autonomously staying in front of the athlete. No-one has ever tested the range of an unmanned electric rover. If an electric scooter with lead acid batteries can go 10 miles, something unmanned with lipos should go for 30 miles. For all the investment in pedometer wrist bands that don't work, why can't someone invest in a simple rover?
Posted by Jack Crossfire | Dec 19, 2013 @ 06:08 PM | 2,946 Views



Interesting to look at what big named, over hyped projects failed. It ain't the sea of instant $150,000 jackpots on the news.


Another RC controller based on the tilt sensing craze, pitched by guys with a legion of artists who were a little too zealous about an industrial design craze that never happened.


Then, there is something more similar to Marcy 1. 2 guys pledged $100 for a phone controlled copter & it failed.

...Continue Reading
Posted by Jack Crossfire | Dec 18, 2013 @ 11:11 PM | 2,962 Views



Marcy1 Phone Control (3 min 27 sec)



There it is. If there is a Kickstarter campaign, that's going to be the product. Flying with the phone is not as easy as the sticks, but it's cheap. Bluetooth initialization is still a buster. Flight time on a 450mAh, 7.4V battery is 9 minutes.


Interestingly, robugtix.com sells a controller made of a bare circuit board & Xbee.



To get that level of customization, they have to charge a bit more than the price of a standard toy controller.
Posted by Jack Crossfire | Dec 18, 2013 @ 02:58 AM | 2,393 Views
So making a 2 stick controller on a touch screen requires detecting 2 simultaneous touch points. The challenge with a stick controller is keeping a touch point corresponding to a stick applied to that stick, no matter where the touch point moves. If the touch point corresponding to the cyclic was applied to the throttle when it moved to the left side of the screen, it would be disastrous.


Basically, the Goog has tried at least 3 methods for handling multitouch in the Android API. There were ACTION_DOWN, ACTION_POINTER_2_DOWN, ACTION_POINTER_3_DOWN ... macros. Then they tried some really painful ACTION_POINTER_INDEX_SHIFT, ACTION_POINTER_ID_MASK macros which Eclipse says are now depreciated. There's no evidence of what the current, accepted way of doing it is.

The problem is the only way of knowing the current state of the touch screen is to trap a serial stream of MotionEvent events, then construct a table of all the touch spots on your own. There's no way to poll the touch screen or get the current state of the screen with a bunch of gets.

So you get a serial stream of MotionEvent events. The MotionEvent contains an x,y coordinate for every touch point, but there is only 1 action variable describing whether a single touch point in that list was pressed or released. For every press or release of a touch point, a new MotionEvent has to be received with the x,y coordinates for all the points & an action applying to 1 point.

If there is only 1 touch point,...Continue Reading
Posted by Jack Crossfire | Dec 17, 2013 @ 04:42 AM | 2,226 Views
Robotech intro in STEREO (1 min 34 sec)


Discovered selections of the soundtrack, but not all of it, were recorded in stereo. 1 stereo segment was the intro. In the 1995 CD, they combined stereo segments with mono segments in the same track to create the illusion that the entire track was stereo.


Unfortunately, there's no way to get the sound effects from the original intro. There are other goo tube videos with crappy sound effects & lousy clips where kids tried to enhance the intro.


...Continue Reading
Posted by Jack Crossfire | Dec 16, 2013 @ 05:16 AM | 2,648 Views


Best stencil job of them all. A joy to fly, but the spruce isn't retaining its bend.


...Continue Reading
Posted by Jack Crossfire | Dec 15, 2013 @ 03:11 AM | 3,124 Views
Flying monocopter with stick controller (7 min 29 sec)


Not as easy as a Blade MCX, but not as hard as a T-Rex 450. Quite a bit of power & control effectiveness. You can almost see a sport evolving out of it, with some pilots becoming very skilled. With virtually no wing loading, it wouldn't be very fun outside.
Posted by Jack Crossfire | Dec 13, 2013 @ 12:54 AM | 2,334 Views


This arrangement of boards had just enough space to fit the cover on. There's no easy place for a Lipo battery. Flying it with sticks revealed the latest monocopter design to be extremely buoyant. Horizontal oscillation abounds, with the extremely low head speed, but seems to be controllable with active damping. The head speed is so low, there's plenty of horizontal authority.


Flying with the compass in the controller was not as easy as thought. Your mind expects the azimuth to be relative to your eyes, not relative to the controller.
Posted by Jack Crossfire | Dec 12, 2013 @ 04:55 AM | 2,607 Views
After much battling with 2 PICs, 2 boards, & the SDCC toolchain, the 8 bit PICs with SDCC clearly don't have the horsepower to do any significant math. They can't do the tilt compensation for a compass. It may be a compiler limitation or a stack limitation. Fixed point, 4x4 matrix calculations on the PIC quickly resulted in random results.


The BANKSEL optimization in SDCC absolutely doesn't work, once you get over 256 bytes of RAM. Using the __naked keyword anywhere but the simplest program doesn't work.


The return address stack is only 31 levels, which might be exhausted in a complicated math function. So the idea was to use an el cheapo PIC to make a standalone stick controller with heading detection that would allow the azimuth on a monocopter to always point nose out.


Having a standalone stick controller is a drastically different experience than a touch screen or a stick controller tethered to a computer & a test article would be valuable in comparing the experiences.


Of course, the reason for the PIC was manely because it didn't seem a big enough problem to justify any more horsepower & it seemed mass producible. In reality, it absolutely is not cost effective to mass produce a stick controller in lieu of a phone interface & it doesn't have the publicity of a phone interface.


It can minimize the aircraft weight by using chip radios, but at the very least, the aircraft weight can be minimized with a bluetooth chip...Continue Reading
Posted by Jack Crossfire | Dec 04, 2013 @ 11:58 PM | 2,549 Views

The home made USB PIC programmer has been around for around 6 years. After all those PICs & all that time waiting for its extremely slow data rate of 600 bits/sec, it finally had a debugging session with an oscilloscope that exposed the problem. A single bit error & now it's up to 166kbits/sec. It's still very slow, but bearable.

166khz is almost as fast as an agnostic bit banging protocol over USB can go. Past strategies used a bootloader to speed it up, but it needed a lot of extra resistors & tended to erase the PIC on its own.

The official Pickit programmer was once $30. Now, it's $45. Any future paid project would definitely involve buying the official programmers instead of making them from scratch.
Posted by Jack Crossfire | Nov 30, 2013 @ 08:47 PM | 2,676 Views
a high speed, FPGA driven camera for flying Marcy 1

The monocopter remanes an interesting way to fly with the least amount of material. The ground based camera isn't very practical outside of a demo, since it can only hover in a single place. The FPGA version still requires highly controlled lighting. Hovering in a lit room is still more useful than hovering in a dark room.

A manually flown monocopter with a basic 3 channel stick controller may be extremely old fashioned, but the aerodynamics have gotten to the point where it could be a very exciting toy. Don't think any tablet interface is going to provide the same experience as old fashioned joysticks, although tablets provide a different experience.

If the user wants it to fly itself, it could be a rare enough occurrence to get by with a basic webcam that only works in the dark.




a balancing robot

It would be focused on autonomous mapping, using IR sensors or sonar. Another idea is using an articulated camera system to automatically make a 3D world. Making a 3D world like street view or a map is just more easily done with a human carrying around the sensor than with a robot. So maybe the focus could be on a map making sensor itself.

A balancing robot would make more sense if there was a day job coming that involved the ATmega328. Trade shows were not a viable way to fund startups, in the old days. We used to leave Las Vegas trade shows with 200 very promising leads, but they were more interested in...Continue Reading
Posted by Jack Crossfire | Nov 30, 2013 @ 07:19 PM | 2,499 Views
Running a startup on Haskell (50 min 23 sec)


There's a guy who makes you feel small. He's done a lot more in the same time you've been alive than you ever did. His formal education only went up to a BS in CS, yet he did everything from teaching a class at Stanford to starting a company, writing a book, & managing engineers.

Some items of note were he never mentioned working on something that wasn't in a formal environment, collaborating with other people who saw what he was doing. Where the rest of us might have hacked on a problem that no-one else was, alone in our bedrooms in college, he mentioned working with a bunch of other research students in the same room, on a fairly established problem.

Then, in professional life, he mentioned working on a small project outside of his day job, but it was with someone else & it was still related to his day job. He never did anything that wasn't a collaboration.

His book was a collaboration. Instead of lazily writing a wiki like most of us would, his 1st move was to approach O'Reilly to see if they would publish it formally. It's definitely a different way of thinking to make sure everything you do is done in a formal environment or part of a job, but it's probably reality if you want to make money.

He never mentioned any hardships with anything he did. The opportunities & money just effortlessly came. He mentioned working on obscure technologies as making resumes stand out, because it showed when...Continue Reading
Posted by Jack Crossfire | Nov 30, 2013 @ 03:20 PM | 2,229 Views
There are finally enough parts in the apartment to make a very small but decent balancing robot. If kickstarter existed 10 years ago, there would be a lot of balancing robot schemes instead of 3D printer schemes.


It's long been a desire to build one, but it never had a purpose. At most, it could do some kind of indoor mapping. 1 of the more functional balancing robots used an object tracking algorithm to navigate a course.


RS4 - Self balancing Raspberry Pi OpenCV image processing Robot Update 2 (1 min 1 sec)



It was a bit faster than the object tracking rovers I built because it used a raspberry pi for the machine vision & had a fully articulated camera. Trying to do that with a fixed camera, an STM32 capturing 6fps & offloading the object recognition over a wifi network was really slow.


Interestingly, he derived exactly the same algorithm for recognizing the objects that I used a year earlier. The key in both cases was to surround the object with a rectangle & use the rectangle to correct the perspective. Then, both of us calculated the difference between the object & a database of objects.


He later did some fudging to the blob detection. He appeared to shrink, then grow the blobs to eliminate noise.


At this point, detecting signs is pretty germane. Indoor mapping would be the next big thing. Telepresence using a video feed has never been practical because radio range has never been good enough.


1 fascination with balancing robots is that they can make money if a suitable application can be found. A conventional 4 wheeled robot is never going to make money. There is a market for a 4 wheeled chassis as an educational kit, but not a finished robot. Remote controlled cars are selling for $17 & change, these days, while Sparkfun is able to command $99 for a robot kit intended for education.
Posted by Jack Crossfire | Nov 29, 2013 @ 08:23 PM | 2,337 Views
Posted by Jack Crossfire | Nov 28, 2013 @ 01:27 AM | 2,952 Views
The early days of air travel, the vehicles & the crashes are an interesting read. It was as dangerous as it looked. There are no detailed descriptions of the accidents but engine failures seemed to abound. There were lots of water landings when engines failed. Water landings were usually fatal.

Gizmodo only covered Imperial Airways, which was real primitive. Your ride as an Imperial Airways passenger, on the very 1st flights in 1924 would have been this:




The De Havilland DH34. Early adopting was really early adopting in those days. The pilot sat outside. 1 engine was all you would ever need. The entire airline fleet amounted to 6 planes. If you were unlucky enough to be flying on Dec 24, 1924, you wouldn't have made it presumably because the 1 engine died shortly after takeoff, but there were no flight data recorders in those days.


In 1926, your ride was upgraded to the new & improved



Handley Page W.8. Those were real radiators with real antifreeze, exhaust manifolds, & oil pans hanging off the struts. At least it was easy to see if an oil line was broken, which they often were. It was quite large for a biplane. The pilot sat outside, behind the nose, all the better to reinforce if they were heading towards the ground.

...Continue Reading
Posted by Jack Crossfire | Nov 27, 2013 @ 10:36 PM | 2,725 Views