Learn And Build A High Side Switch

As electronics engineer I have a mental collection of circuits that I’ve gathered over the years, much like a mechanic collects specialized tools as they work. All engineers do this and the tools in their tool boxes usually represent their project history and breadth.

A useful circuit to have in designer’s toolbox is the “high side switch”. Like it sounds, this is a circuit that switches the “high side” or positive voltage to a load.

We usually tend to switch things to ground as seen by outputs such as an Open Collector output, the reason being that ground usually is a known entity and is usually low impedance and is at a known voltage. But there are advantages to using a high-side switch in your circuits.

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Don’t Understand The Periodic Table? It’s Just A Quantum Truth Table

In the wee hours of the late 17th century, Isaac Newton could be found locked up in his laboratory prodding the secrets of nature. Giant plumes of green smoke poured from cauldrons of all shapes and sizes, while others hissed  and spat new and mysterious chemical concoctions, like miniature volcanoes erupting with knowledge from the unknown. Under the eerie glow of twinkling candle light, Newton would go on to write over a million words on the subject of alchemy. He had to do so in secret because the practice was frowned upon at that time.  In fact, it is now known that alchemy was the ‘science’ in which he was chiefly interested in. His fascination with turning lead into gold via the elusive philosopher’s stone is now evident. He had even turned down a professorship at Cambridge and instead opted for England’s Director of Mint, where he oversaw his nation’s gold repository.

Not much was known about the fundamental structure of matter in Newton’s time. The first version of the periodic table would not come along for more than a hundred and forty years after his death. With the modern atomic structure not surfacing for another 30 years after that. Today, we know that we can’t turn lead into gold without setting the world on fire. Alchemy is recognized as a pseudoscience, and we opt for modern chemistry to describe the interactions between the elements. Everyone walking out of high school knows what atoms and the periodic table are. They know what the sub-atomic particles and their associated electric charges are. In this article, we’re going to push beyond the basics. We’re going to look at atomic structure from a quantum mechanical view, which will give you a new understanding of why the periodic table looks the way it does. In fact, you can construct the entire periodic table using nothing but the quantum numbers.

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9th Grader Arrested, Searched For Building A Clock

A 14-year-old in Dallas, Texas has been arrested for bringing a clock to his school. [Ahmed Mohamed] could be any one of us. He’s a tinkerer, pulling apart scrap appliances and building projects from the parts. He was a member of the his middle school robotics team. The clock was built from a standard four digit seven segment display and a circuit board. [Ahmed] built the circuit inside a Vaultz hard pencil case like this one. He then did what every other experimenter, inventor, hacker, or maker before him has done: He showed off his creation.

Unfortunately for [Ahmed] one of his teachers immediately leapt to the conclusion that this electronic project was a “hoax bomb” of some sort. The police were called, [Ahmed] was pulled out of class and arrested. He was then brought to a detention center where he and his possessions were searched. [Ahmed] is now serving a three-day suspension from school. His clock is considered evidence to be used in a possible criminal case against him.

If this situation doesn’t get your blood boiling, then we don’t know what does. Not only is there a glaring racial issue here, but also an issue of allowing kids to bring their projects to school. We hope you’ll join us in expressing outrage at this whole debacle, as well as supporting [Ahmed] in any way you can. Let’s join together as a community to make sure a few small-minded individuals don’t break the spirit of this budding hardware hacker.

For anyone out there who would like to support [Ahmed]’s education even when his school won’t, [Anil Dash] is will be in contact with the family later today. We’re offering a gift card for the hackaday store and we would assume other contributions would also be welcome. -Ed.

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No User Serviceable Parts Inside? The Rise Of The Fix-It Culture

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[Source: 1950s Television]
My first job out of high school was in a TV shop. I was hired mainly for muscle; this was the early 1980s and we sold a lot of console TVs that always seemed to need to be delivered to the third floor of a walk up. But I also got to do repair work on TVs and stereos, and I loved it. Old TVs from the 60s and 70s would come in, with their pre-PCB construction and hand-wired chassis full of terminal strips and point to point wiring that must have been an absolute nightmare to manufacture. We’d replace dodgy caps, swap out tubes, clean the mechanical tuners, and sometimes put a new picture tube in  – always the diagnosis that customers dreaded the most, like being told they’d need a heart transplant. We kept those old sets alive, and our customers felt like they were protecting their investment in their magnificent Admiral or Magnavox console with the genuine – and very, very heavy – walnut cabinet.

I managed to learn a lot from my time as a TV repairman, and I got the bug for keeping things working well past the point which a reasonable person would recognize as the time to go shopping for a new one. Fixing stuff is where I really shine, and my house is full of epic (in my mind, at least) repairs that have saved the family tens of thousands of dollars over the years. Dishwasher making a funny noise? I’ll just pull it out to take a look. You say there’s a little shimmy in the front end when you brake? Pull the car into the garage and we’ll yank the wheels off. There’s basically nothing I won’t at least try to fix, and more often than not, I succeed.

I assumed that my fix-it bug made me part of a dying breed of cheapskates and skinflints, but it appears that I was wrong. The fix-it movement seems to be pretty healthy right now, fueled in part by the explosion in information that’s available to anyone with basic internet skills.

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Xerox PARC Exploding Chip

This Post Will Self Destruct In 10 Seconds

Ah yes, the classic Mission Impossible ultimate message security — after verification and playing the message, poof — it’s gone. You could design explosives into your electronics to have the same effect… or you can use Xerox PARC’s new chip, which features a self-destruct mode.

Wait, what? Yup — some engineer at Xerox decided to develop a chip that can literally self-destruct. It was developed for DARPA’s vanishing programmable resources project, and well, it sounds pretty promising for the future of high-security applications. Continue reading “This Post Will Self Destruct In 10 Seconds”

Why 100 Watt EBay LEDs Are Not Your Friends

LEDs are amazing things. As time marches on, they are being used in more and more lighting applications – everything from household bulbs to automotive headlights. But the push for smaller, cheaper, and brighter LEDs seems to have hit a snag for some of the less reputable manufactures.

Case in point, [bigclivedotcom] has been testing of some 100 Watt LEDs from eBay. When these LEDs work correctly, they put out a face-melting beam of light that you wouldn’t dare looking into (picture the scene from Raiders of the Lost Ark). They also have some unusual specs for an LED, like running on 30 Volts – and that’s a lot compared to the forward voltage of most LEDs at around 2.5 volts@20 mA.

So what gives? Well many of these high-wattage LEDs use a string of several LEDs in series. And as [bigclivedotcom] points out, this can be a real problem when a few of the LEDs begin to fail and act more like a low value resistor than a typical LED. In the videos after the break you can see [bigclivedotcom] test the LEDs to get a better look and what’s happening and why.

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Let Skynet Become Self-Aware!

Not so long ago, it was hard to fly. Forget actual manned aircraft and pilots licenses; even flying model aircraft required hours of practice, often under the tutelage of a master at a flying field. But along with that training came an education in the rules of safe flight, including flying at a designated airfield and watching out for obstacles.

We accidentally messed that up. We in the drone industry made aircraft super easy to fly — perhaps too easy to fly. Thanks to smart autopilots and GPS, you can open a box, download an app and press “take off”. The copter will dutifully rise into the air and wait there for further instructions — no skill required. And it will do this even if you happen to be in an NFL football stadium in the middle of a big game. Or near an airport. Or in the midst of a forest fire.

The problem is that along with taking training out of the process of flying a drone, we inadvertently also took out the education process of learning about safe and responsible flight. Sure, we drone manufacturers include all sorts of warning and advisories in our instructions manual (which people don’t read) and our apps (which they swipe past), and companies such as DJI and my own 3DR include basic “geofencing” restrictions to try to keep operators below 400 feet and within “visual line of sight”. But it’s not enough.

Every day there are more reports of drone operators getting past these restrictions and flying near jetliners, crashing into stadiums, and interfering with first responders. So far it hasn’t ended in tragedy, but the way things are going it eventually will. And in the meantime, it’s making drones increasingly controversial and even feared. I call this epidemic of (mostly inadvertent) bad behavior “mass jackassery”. As drones go mass market, the odds of people doing dumb things with them reach the singularity of certainty.

We’ve got to do something about this before governments do it for us, with restrictions that catch the many good uses of drones in the crossfire. The reality is that most drone operators who get in trouble aren’t malicious and may not even know that what they’re doing is irresponsible or even illegal. Who can blame them? It’s devilishly hard to understand the patchwork quilt of federal, state and local regulations and guidelines, which change by the day and even the hour based on “airspace deconfliction” rules and FAA alerts written for licensed pilots and air traffic control. Many drone owners don’t even know that such rules exist.

Drones Themselves Should Know Rules of Each Area

Fortunately, they don’t have to. Our drones can be even smarter — smart enough to know where they should and shouldn’t fly. Because modern drones are connected to phones, they’re also connected to the cloud. Every time you open their app, that app can check online to find appropriate rules for flight where you are, right then and there.

Here’s how it works. The app sends four data fields to a cloud service: Who (operator identifier), What (aircraft identifier), Where (GPS and altitude position) and When (either right now or a scheduled time in the case of autonomous missions). The cloud service then returns a “red light” (flight not allowed), a “green light” (flight allowed, with basic restrictions such as a 400 feet altitude ceiling), or “yellow light” (additional restrictions or warnings, which can be explained to the operator in context and at the point of use).

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Right now industry groups such as the Dronecode Foundation, the Small UAV Coalition (I help lead both of them, but this essay just reflects my own personal views) and individual manufacturers such as 3DR and DJI are working on these “safe flight” standards and APIs. Meanwhile, a number of companies such as Airmap and Skyward are building the cloud services to provide the up-to-date third-party data layer that any manufacturer can use. It will start with static no-fly zone data such as proximity to airports, US national parks and other banned airspace such as Washington DC. But it will quickly add dynamic data, too, such as forest fires, public events, and proximity to other aircraft.

(For more on this, you can read a white paper from one of the Dronecode working groups here and higher level description here.)

There’s Always a Catch

Of course, this system isn’t perfect. It’s only as good as the data it uses, which is still pretty patchy worldwide, and the ways that the manufacturers implement those restrictions. Some drone makers may choose to treat any area five miles from an airport as a hard ban and prohibit all flight in that zone, even at the cost of furious customers who had no idea they were five miles from an airport when they bought that toy at Wal-mart (nor do they think it should matter, since it’s just a “toy”). Other manufacturers may choose to make a more graduated restriction for the sake of user friendliness, adding a level of nuance that is not in the FAA regulation. They might ban, say, flight one mile from an airport, but only limit flight beyond that to something like 150ft of altitude (essentially backyard-level flying).

That’s a reasonable first step. But the ultimate safe flight system would go a lot further. It would essentially extend the international air traffic control system to millions of aircraft (there are already a million consumer drones in the air) flown by everything from children to Amazon. The only way to do that is to let the drones regulate themselves (yes, let Skynet become self-aware).

Peer-to-peer Air Traffic Control

There’s a precedent for such peer-to-peer air traffic control: WiFI. Back in the 1980s, the FCC released spectrum in the 2.4 Ghz band for unlicensed use. A decade later, the first 802.11 standards for Wifi were released, which was based on some principles that have application to drones, too.

  1. The airspace used is not otherwise occupied by commercial operators
  2. The potential for harm is low (in the case of WiFi, low transmission power. In the case of drones, low kinetic energy due to the weight restrictions of the “micro” category)
  3. The technology has the capability to self-”deconflict” the airspace by observing what else is using it and picking a channel/path that avoids collisions.

That “open spectrum” sandbox that the FCC created also created a massive new industry around WiFi. It put wireless in the hands of everyone and routed around the previous monopoly owners of the spectrum, cellphone carriers and media companies. The rest was history.

Quadcopter ThumbWe can do the same thing with drones. Let’s create an innovation “sandbox” with de minimus regulatory barriers for small UAVs flying within very constrained environments. The parameters of the sandbox could be almost anything, as long as they’re clear, but it should be kinetic energy and range based (a limit of 2kg and 20m/s at 100m altitude and 1,000m range within visual line of sight would be a good starting point).

As in the case of open spectrum, in relatively low risk applications, such as micro-drones, technology can be allowed to “self-deconflict the airspace” without the need for monopoly exclusions such as exclusive licences or regulatory permits. How? By letting the drones report their position using the same cellphone networks they used to get permission to fly in the first place. The FAA already has a standard for this, called ADS-B, which is based on transponders in each aircraft reporting their position. But those transponders are expensive and unnecessary for small drones, which already know their position and are connected to the cloud. Instead, they can use “virtual ADS-B” to report their position via their cell network connections, and that data can be injected into the same cloud data services they used to check if their flight was safe in the first place.

Once this works, we’ll have a revolution. What WiFi did the telecoms industry, autonomous, cloud-connected drones can do to the aerospace industry. We can occupy the skies, and do it safely. Technology can solve the problems it creates.


About the Author

judge-thumb-AndersonChris Anderson (@Chr1sa) is the CEO of 3D Robotics and founder of DIY Drones. From 2001 through 2012 he was the Editor in Chief of Wired Magazine. Before Wired he was with The Economist for seven years in London, Hong Kong and New York.

The author of the New York Times bestselling books The Long Tail and Free as well as the Makers: The New Industrial Revolution.

His background is in science, starting with studying physics and doing research at Los Alamos and culminating in six years at the two leading scientific journals, Nature and Science.

In his self-described misspent youth [Chris] was a bit player in the DC punk scene and amusingly, a band called REM. You can read more about that here.

Awards include: Editor of the Year by Ad Age (2005). Named to the “Time 100,” the newsmagazine’s list of the 100 most influential people in the world (2007). Loeb Award for Business Book of the Year (2007). Wired named Magazine of the Decade by AdWeek for his tenure (2009). Time Magazine’s Tech 40 — The Most Influential Minds In Technology (2013). Foreign Policy Magazine’s Top 100 Global Thinkers (2013).