Nov 10
Things that fly are neat, and pretty useful. I really like neat so I’m building something that flies: a small-scale quadrotor unmanned aerial vehicle or UAV. It’s conceptually really basic, just a cross with four motors at the ends that provide lift and by changing the power to each motor allow you to control where in goes. Simple.
The hard part is figuring out how to control it. In fact its too complex to be controlled by a human operator alone. Thus the main problem is to write some smart software that either helps stabilize the quadrotor or flies it with no human input. There’s a whole engineering field devoted to solving issues involved in controlled highly dynamic systems: control theory, my new friend I’ll surely be getting very familiar, if not quite intimate, with.
But not just yet. Before the software comes the hardware needed to run it. And for something flying through the air you need sensors in every direction to tell you what’s going on in terms of your motion. A 3-axis linear accelerometer and a 3-axis gyrometer are what’s needed (and sufficient), as seen below in the schematic (Click for a closer look). Those plus a microcontroller, power supply and wireless module.
Next comes the board layout.
Oct 30
Halloween is tomorrow. Just in time I’ve completed a little project that I call Ping Pong Pumpkins. Simple idea: power an LED with a coin cell battery (ala LED Throwies) and put inside a decorated orange ping pong ball and you have a mobile electronic jack-o-lantern (an iPumpkin?).
It’s as unique as you make it and a fun, quick little way to decorate. Did I mention it’s portable? Have a happy Halloween.
Oct 29
327 feet tall, 2.6 million pounds of thrust, zero to Mach 1 in 39 seconds. The NASA Ares I-X test rocket, part of the Constellation program for the next generation of spacecraft. Launched 11:30AM ET yesterday morning.
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Oct 27
The experimental method is useful for figuring things out, but it is time consuming. Luckily many people like to share their results thus avoiding unnecessarily redoing lots of work. This is especially good when it saves my time (my time being very valuable). So I’m glad I found a recent exploration of powering LEDs just by connecting them to a small “coin” battery, which is not unheard of (see LED Throwie) but not the standard procedure in most circuits. Happily the findings are good news.
Normally when you don’t stick a resistor (something that stops too much current from flowing through a device) in series with a LED the LED starts to burn and short out: not good unless you like the smell of burning plastic. But small 3 volt batteries like those used in remote controls and so on have an internal resistance in them which prevents a death of flames for a LED attached to them. Additionally, with a white LED that needs about 3 volts to light up the basic circuit (LED + battery) will stay lit for over a week. That’s the key piece of info I required.
That’s precisely what I needed to know for my Ping Pong Pumpkins project which I will be treating the world to this Thursday in a make-your-own event. It would be some trick to have them not last through Halloween.
Oct 26
LEDs are cool, and so is Halloween. So why not combine them? Why not indeed. EMSL does so just in time with their large and very orange LED matrix.
Made using their very own circuit kit Peggy 2 that makes it easy make a custom matrix: just add LEDs and a little bit of solder.
I wonder if I could do something creative and fun using LEDs for Halloween? Stay tuned.
Oct 25
Cool animatronic hand, using 15 joints to create realistic motion. Created by the wonderfully job-titled “Imagineers” that work for Disney.
Oct 14
Above is a 5X photo of Olivine inclusions in gabbro taken by Bernardo Cesare. One of my favorites in Nikon’s Small World 2009 showcase of exceptional small-scale microscope-based photography. Alive, inorganic, tiny, and the really tiny. A revealing look at the lower end of the scale of things.
Sep 26
Go watch this video. Little robots are not supposed to be able to do that. That being jump over obstacles up to 60 times their size, up to 30 times, rendering fences, moats, and other methods of keeping killer robots at bay ineffective.
This particular robot is the Precision Urban Hopper created by Boston Dynamics and Sandia National Laboratories. It’s autonomous, being guided by GPS and is planned to be used in law enforcement, among other uses. So if you’re ever being chased by it I recommend you get some place that is unreachable by hops.
Sep 25
My iPod touch is not as robust as it should be. I found this out through first-hand experimentation, under conditions while not commonly encountered are none the less in the range of possible user environments. Specifically, I found myself in a dark, loud (> 100dB), closely packed, foamy environment for approximately 4.5 hours, with the iPod in my pocket, a common area to store it. The foam turned out to be an issue.
Upon waking up the next morning I wanted to check the time and reached for my iPod, as there’s an app for that. This is when the trouble started. I was unable to use the capacitive touchscreen to select the clock as it would not register my touches. Instead a flurry of phantom touches and motions were being triggered across the screen. It was like it had a mind of its own: this is what must be meant by the phrase “the ghost in the machine.” It was impossible to use in any meaningful fashion with apps launching, then closing at random.
Although the exterior of the device showed little foam residue I was forced to conclude based on the clear evidence in front of me that foam had made it’s way into the device and furthermore, and more significantly, that foam has capacitive properties, which might be a new scientific discovery (as far as I know).
I was surprised by the foam effect as I was sure as part of the rigorous testing stage of product development Apple would have tested the device out in a wide range of conditions to ensure it worked properly. Apparently they missed the foam test. Had they tested the device in foam this issue would have been discovered and a solution quickly found. For instance it could have been possible to either stop foam from entering the device in the first place or to filter out any foam-induced effects caused by adding a randomly changing value capacitor in between each and every piece of the circuit. Probably fairly straightforward I imagine.
I’ve contacted Apple and await a resolution, maybe a firmware update will fix it.
UPDATE: It has since gradually returned to normal, pre-foamage, operation. Foam does have a tendency to dissipate with time. I guess it was better designed than I initially gave it credit. My apologies Apple.
Aug 26
These structures found in the wilderness of Russia would be quite a surprise to come upon, of seemingly unknown purpose and the rusting metal forms a stark contrast with the forest evergreens that they find themselves living among. They have a strange beauty to them similar to other old and abandoned industrial sites, except with perhaps a darker, more malevolent feel. They’re just fantastic sci-fi-ish creations. But what are they and why were the built?
(photos by master-z-great)
They are the high voltage generators of the Experimental Grounds for High-Voltage Generation, an old Russian experimental outpost. They most resemble, but on a larger scale and more complex and varied design, the more standard Tesla coil which is usually is a tower topped with a large torus, or donut-shaped, metal surface which very long (proportional to the output voltage) lightning-like bolts emerge. With towers of this size you could expect some really long squirming threads of excited plasma, upwards of 100 feet or more.
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