Working For Elon Musk

August 31, 2016 by Steven Dufresne 163 Comments

One of my favorite types of science fiction character is found in the books of Ben Bova; a business mogul who through brilliance, hard work, and the force of personality drives mankind to a whole new level in areas such as commercializing space, colonizing the stars, battling governments, and thwarting competitors.

It is possible to name a few such characters in real life — influencing the electricity industry was George Westinghouse, automobiles was Henry Ford, and more recently Steve Jobs and Elon Musk. With Elon’s drive we may all finally be driving electric cars within 20 years and spreading out into space with his cheap rockets. Due to the latter he may be the closest yet to one of Bova’s characters.

So what’s it like to work for Elon Musk at Tesla or SpaceX? Most of us have read articles about him, and much that he’s written himself, as well as watched some of his many interviews and talks. But to get some idea of what it’s like to work for him I greatly enjoyed the insight from Ashlee Vance’s biography Elon Musk – Tesla, SpaceX, and the Quest for a Fantastic Future. To write it Vance had many interviews with Musk as well as those who work with him or have in the past. Through this we get a fascinating look at a contemporary mogul of engineering.

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Amazon Dash Button Finds Your Phone

August 31, 2016 by Elliot Williams 41 Comments

This scene replays quite often in our house: my wife has misplaced her cell phone so she asks me to call her. But where did I leave my cell phone? And the race is on! Who will find their phone first to call the other?

[Zapta] solves this problem with his Phone Finder. The system comes in two parts: a base station with WiFi that’s also connected to the house’s phone line, and an arbitrary number of Amazon Dash buttons that trigger dialing commands.

[Zapta] presses a Dash button, which connects over WiFi to the base station. The base station recognizes the MAC address of the button, looks up and dials the corresponding missing cell phone. This solves the need-a-phone-to-find-a-phone problem very neatly, and since Dash buttons are dirt cheap they can be scattered liberally around the house. They’re clearly marked “his” and “hers” suggesting a similar domestic dynamic.

If we were implementing the base station from scratch, we’d probably try to figure out how a single ESP8266 could do all of the heavy lifting, but browsing through [Zapta]’s GitHub and the included circuit diagram (PDF) demystifies the phone-line interface.

In the early days of cordless phones, we used to joke that a solution to losing them would be to attach a string and tie them to the wall. (Luddites!) We’re glad to see [Zapta] take this project in the opposite direction — using technological overkill to solve the unintended problems that arise from technological progress.

Tricking Duck Hunt To See A Modern LCD TV As CRT

August 30, 2016 by Jenny List 47 Comments

A must-have peripheral for games consoles of the 1980s and 1990s was the light gun. A lens and photo cell mounted in a gun-like plastic case, the console could calculate where on the screen it was pointing when its trigger was pressed by flashing the screen white and sensing the timing at which the on-screen flying spot triggered the photo cell.

Unfortunately light gun games hail from the era of CRT TVs, they do not work with modern LCDs as my colleague [Will Sweatman] eloquently illustrated late last year. Whereas a CRT displayed the dot on its screen in perfect synchronization with the console output, an LCD captures a whole frame, processes it and displays it in one go. All timing is lost, and the console can no longer sense position.

[Charlie] has attacked this problem with some more recent technology and a bit of lateral thinking, and has successfully brought light gun games back to life. He senses where the gun is pointing using a Wiimote with its sensor bar on top of the TV through a Raspberry Pi, and feeds the positional information to an Arduino. He then takes the video signal from the console and strips out its sync pulses which also go to the Arduino. Knowing both position and timing, the Arduino can then flash a white LED stuck to the end of the light gun barrel at the exact moment that part of the CRT would have been lit up, and as far as the game is concerned it has received the input it is expecting.

He explains the timing problem and his solution in the video below the break. He then shows us gameplay on a wide variety of consoles from the era using the device. More information and his code can be found on his GitHub repository.

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Review: Monoprice Maker Ultimate 3D Printer

August 30, 2016 by Brian Benchoff 116 Comments

A few months ago, a very inexpensive 3D printer appeared on Monoprice. My curiosity for this printer was worth more than $200, so I picked one of these machines up. The Monoprice MP Select Mini is an awesome 3D printer. It’s the perfect printer to buy for a 13-year-old who might be going through a ‘3D printing phase’. It’s a great printer to print a better printer on. This printer is a sign the 3D printing industry is not collapsing, despite Makerbot, and foreshadows the coming age of consumer 3D printers.

The MP Select Mini isn’t Monoprice’s only 3D printer; the printer I bought was merely the ‘good’ printer in the good-better-best lineup. Since my review of the MP Select Mini, Monoprice has introduced their top of the line, the Maker Ultimate 3D printer. Monoprice asked if I would like to take a look at this offering, and I’m more than happy to oblige.

After a week of burn-in, I can safely say you’re not wasting your money on this $700 3D printer. It’s not a starter printer — it’s one that will last you a long time. 2016 is the beginning of the age of consumer 3D printers, and the Monoprice Maker Ultimate is more than proof of this.

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Fixing The Ampere: Redefining The SI Unit

August 30, 2016 by Elliot Williams 105 Comments

We all know that it’s not the volts that kill you, it’s the amps. But exactly how many electrons per second are there in an amp? It turns out that nobody really knows. But according to a press release from the US National Institute of Standards and Technology (NIST), that’s all going to change in 2018.

The amp is a “metrological embarrassment” because it’s not defined in terms of any physical constants. Worse, it’s not even potentially measurable, being the “constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 meter apart in vacuum, would produce between these conductors a force equal to 2 x 10–7 newton per meter of length.” You can’t just order a spool of infinite length and negligible cross-section wire and have it express shipped.

So to quantify the exact number of electrons per second in an amp, the folks at NIST need an electron counter. This device turns out to be a super-cooled, quantum mechanical gate that closes itself once an electron has passed through. Repeatedly re-opening one of these at gigahertz still provides around a picoamp. Current (tee-hee) research is focused on making practical devices that push a bit more juice. Even then, it’s likely that they’ll need to gang 100 of these gates to get even a single microamp. But when they do, they’ll know how many electrons per second have passed through to a few tens of parts per billion. Not too shabby.

We had no idea that the amp was indirectly defined, but now that we do, we’re looking forward to a better standard. Thanks, NIST!

Thanks [CBGB123B] for the tip!

How Accurate Is Microstepping Really?

August 29, 2016 by Moritz Walter 162 Comments

Stepper motors divide a full rotation into hundreds of discrete steps, which makes them ideal to precisely control movements, be it in cars, robots, 3D printers or CNC machines. Most stepper motors you’ll encounter in DIY projects, 3D printers, and small CNC machines are bi-polar, 2-phase hybrid stepper motors, either with 200 or — in the high-res variant — with 400 steps per revolution. This results in a step angle of 1.8 °, respectively 0.9 °.

Can you increase the resolution of this stepper motor?

In a way, steps are the pixels of motion, and oftentimes, the given, physical resolution isn’t enough. Hard-switching a stepper motor’s coils in full-step mode (wave-drive) causes the motor to jump from one step position to the next, resulting in overshoot, torque ripple, and vibrations. Also, we want to increase the resolution of a stepper motor for more accurate positioning. Modern stepper motor drivers feature microstepping, a driving technique that squeezes arbitrary numbers of microsteps into every single full-step of a stepper motor, which noticeably reduces vibrations and (supposedly) increases the stepper motor’s resolution and accuracy.

On the one hand, microsteps are really steps that a stepper motor can physically execute, even under load. On the other hand, they usually don’t add to the stepper motor’s positioning accuracy. Microstepping is bound to cause confusion. This article is dedicated to clearing that up a bit and — since it’s a very driver dependent matter — I’ll also compare the microstepping capabilities of the commonly used A4988, DRV8825 and TB6560AHQ motor drivers.

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Hyperuniformity — A Hidden Order Found In The Greatest Set Of Eyes

August 29, 2016 by Will Sweatman 62 Comments

Of all the things evolution has stumbled across, the eye is one of the most remarkable. Acting as sort of a ‘biological electromagnetic transducer’, the eye converts incoming photons into electrical and chemical spikes, known as action potentials. These spikes then drive the brain of the host life form. Billions of years of natural selection has produced several types of eyes, with some better than others. It would be an honest mistake to think that the human eye is at the top of the food chain, as this is not the case. Mammals underwent a long stint scurrying around in dark caves and crevasses, causing our eyes to take a back seat to other more important functions, such as the development of a cortex.

There are color sensitive cones in all eyes. Mammals have three types of cones, which are…wait for it…Red, Blue and Green. Our red and green cones are relatively recent on the evolutionary timescale – appearing about 30 million years ago.

The way these cones are distributed around our eyes is not perfect. They’re scattered around in lumpy, uneven patterns, and thus give us an uneven light sampling of our world. Evolution simply has not had enough time to optimize our eyes.

There is another animal on this planet, however, that never went through “the dark ages” as mammals did. This animal has been soaring high above its predators for over 60 million years, allowing its eyes to reach the pinnacle of the natural selection process. A bald eagle can spot a mouse from over a mile away. Birds eyes have 5 types of light sensitive cones – red, blue and green like our own. But add in violet and a type of cone that can detect no light, or black. But it is the way these cones are distributed around the bird’s eye that is most fascinating, and the subject of today’s article.

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