With 3D printers now dropping to record low prices, more and more people are getting on the additive manufacturing bandwagon. As a long time believer in consumer-level desktop 3D printing, this is a very exciting time for me; the creativity coming out of places like Thingiverse or the 3D printing communities on Reddit is absolutely incredible. But the realist in me knows that despite what slick promotional material from the manufacturers may lead you to believe, these aren’t Star Trek-level replicators. What comes out of these machines is often riddled with imperfections (from small to soul crushing), and can require considerable cleanup work before they start to look like finished pieces.
If all you hope to get out of your 3D printer are some decent toy boats and some low-poly Pokemon, then have no fear. Even the most finicky of cheap printers can pump those out all day. But if you’re looking to build display pieces, cosplay props, or even prototypes that are worth showing to investors, you’ve got some work cut out for you.
With time, patience, and a few commercial products, you can accomplish the ultimate goal: turning a 3D printed object into something that doesn’t look like it was 3D printed. For the purposes of this demonstration I’ll be creating a replica of the mobile emitter used by the “Emergency Medical Hologram” in Star Trek: Voyager. I can neither confirm nor deny I selected this example due to the fact that I’m currently re-watching Voyager on Netflix. Let’s make it look good.
Maria Goeppert-Mayer was one of only two women to win the Nobel prize for physics thus far, the other being Marie Curie. And yet her name isn’t anywhere near as well known as Marie Curie’s. She also worked on the Manhattan Project and spent time during her long career with Enrico Fermi, Max Born, Edward Teller, and many other physics luminaries.
She was “other” in another way too. She followed her husband from university to university, and due to prevailing rules against hiring both husband and wife, often had to take a non-faculty position, sometimes even with no salary. Yet being the other, or plus-one, seemed to give her what every pure scientist desires, the freedom to explore. And explore she did, widely. She was always on the cutting edge, and all the time working with the leading luminaries of physics. For a scientist, her story reads like it’s too good to be true, which is what makes it so delightful to read about.
Information about this one is still tricking in, so take it with a grain of salt, but security company [Bkav] is claiming they have defeated the Face ID system featured in Apple’s iPhone X [Dead link, try the Internet Archive]. By combining 2D images and 3D scans of the owner’s face, [Bkav] has come up with a rather nightmarish creation that apparently fools the iPhone into believing it’s the actual owner. Few details have been released so far, but a YouTube video recently uploaded by the company does look fairly convincing.
For those who may not be keeping up with this sort of thing, Face ID is advertised as an improvement over previous face-matching identification systems (like the one baked into Android) by using two cameras and a projected IR pattern to perform a fast 3D scan of the face looking at the screen. Incidentally, this is very similar to how Microsoft’s Kinect works. While a 2D system can be fooled by a high quality photograph, a 3D based system would reject it as the face would have no depth.
[Bkav] is certainly not the first group to try and con Apple’s latest fondle-slab into letting them in. Wired went through a Herculean amount of effort in their attempt earlier in the month, only to get no farther than if they had just put a printed out picture of the victim in front of the camera. Details on how [Bkav] managed to succeed are fairly light, essentially boiling down to their claim that they are simply more knowledgeable about the finer points of face recognition than their competitors. Until more details are released, skepticism is probably warranted.
Still, even if their method is shown to be real and effective in the wild, it does have the rather large downside of requiring a 3D scan of the victim’s face. We’re not sure how an attacker is going to get a clean scan of someone without their consent or knowledge, but with the amount of information being collected and stored about the average consumer anymore, it’s perhaps not outside the realm of possibility in the coming years.
Where does your mind jump when you hear the mention of electroshock therapy? The use of electrical current to treat various medical conditions has a long and controversial history. Our fascination with the medical applications of electricity have produced everything from the most alarming of patent medicines to life-saving devices like pacemakers and the Automatic External Defibrillator.
The oldest reference I could find is the use of the torpedo fish to allegedly cure headaches, gout, and so on in 43 CE. Incidentally, Torpedo torpedo is an awesome species name.
Much more recently, there has been interest in transcranial direct current stimulation (tDCS). In essence, it’s a technique by which you pass an electrical current (typically about 2 milliamps) between strategically positioned electrodes on your head. The precise reason to do this is a bit unclear; different journal articles have suggested improvements in cognition, learning, and/or the potential treatment of various diseases.
I think most of us here spend a lot of time studying. The idea that a simple, noninvasive device can accelerate that is very attractive. We’ve covered a few people building their own such devices.
Unfortunately, what we want to be true is irrelevant. Superficially, this looks like a DARPA-funded panacea with no clearly established mechanism of action. Various commercial products are being sold that imply (but as usual, don’t directly state) that tDCS is useful for treating pretty much everything, with ample use of ‘testimonials’.
While tDCS can be prescribed by a physician in some countries to complement a stroke rehabilitation regime, for off-label purposes you may as well just go apply a fish to your face. Let’s dig into the literature and products that are out there and see if we can find the promise hiding amidst the hype.
The Open Source Underwater Glider has just been named the Grand Prize winner of the 2017 Hackaday Prize. As the top winner of the Hackaday Prize, the Open Source Underwater Glider will receive $50,000 USD completes the awarding of more than $250,000 in cash prizes during the last eight months of the Hackaday Prize.
More than one thousand entries answered the call to Build Something That Matters during the 2017 Hackaday Prize. Hardware creators around the globe competed in five challenges during the entry rounds: Build Your Concept, Internet of Useful Things, Wings-Wheels-an-Walkers, Assistive Technologies, and Anything Goes. Below you will find the top five finisher, and the winner of the Best Product award of $30,000.
Grand Prize Winner ($50,000 USD): The Open Source Underwater Glider is an AUV (Autonomous Underwater Vehicle) capable of long-term underwater exploration of submarine environments. Where most AUVs are limited in both power and range, the Open Source Underwater Glider does not use active propulsion such as thrusters or propellers. This submersible glides, extending the range and capabilities of whatever task it is performing.
The Open Source Underwater Glider is built from off-the-shelf hardware, allowing anyone to build their own copy of this very capable underwater drone. Extended missions of up to a week are possible, after which the Glider would return home autonomously.
Second Place ($20,000): The Connected Health project aims to bring vital sign monitoring to the masses with a simple, inexpensive unit built around commodity hardware. This monitoring system is connected to the Internet, which enables remote patient monitoring.
Third Place ($15,000): This Assistance System for Vein Detection uses off-the-shelf components and near-IR imaging to detect veins under the skin. This system uses a Raspberry Pi and camera module or a modified webcam and yet is just as reliable as professional solutions that cost dozens of times more than this team’s prototype.
Fourth Place ($10,000): The Adaptive Guitar is an electromechanical system designed to allow disabled musicians to play the guitar with one hand (and a foot). This system strums the strings of a guitar while the musician frets each string.
Fifth Place ($5,000): Tipo is effectively a Braille USB keyboard designed for smartphones. The advent of touchscreen-only phones has unfortunately left the visually impaired without a modern phone. Tipo allows for physical interaction with modern smartphones.
The winner of the Best Product is Tipo : Braille Smartphone Keypad. Tipo is the solution to the problem of the increasingly buttonless nature of modern smartphones. A phone that is only a touchscreen cannot be used by the visually impaired, and Tipo adds a Braille keypad to the back of any phone. It is effectively a USB keypad, designed for Braille input, that attaches to the back of any phone.
The Best Product competition ran concurrently with the five challenge rounds and asked entrants to go beyond prototype to envision the user’s needs, manufacturing, and all that goes into getting to market. By winning the Best Product competition, the creators of Tipo will refine their design, improve their mechanical build, start looking at injecton molding, and turn their 3D printed prototype into a real product that has the ability to change lives.
Congratulations to all who entered the Hackaday Prize. Taking time to apply your skill and experience to making the world better is a noble pursuit. It doesn’t end with the awarding of a prize. We have the ability to change lives by supporting one another, improving on great ideas, and sharing the calling to Build Something that Matters.
Linux can have a somewhat split personality. If you use it as a desktop OS, it has a lot of GUI tools, although sometimes you still need to access the command line. If you use it as a headless server, though, you probably ought to know your way around the command line pretty well. This is especially true if you don’t want to litter up your hard drive (and CPU) with X servers and other peculiarities of the graphical user interface.
Personally, I like the command line, but I am realistic enough to know that not everyone shares that feeling. I’ll also admit that for some tasks — especially those you don’t do very often — it is nice to have some helpful buttons and menus. There are several administration tools that you might be interested in using to handle administration tasks on your Linux machines. I’m going to look at two of them you might want to experiment with that both use a Web browser to provide their interface.
When men were men, and oscilloscopes were oscillographs.
Do you remember your first oscilloscope? Maybe we have entered the era in which younger readers think of a sleek model with an LCD screen, but for the slightly older among us the image that will come to mind is likely to be a CRT-based behemoth. Mine was a 2MHz bandwidth Cossor from the 1950s, wildly outdated by the 1980s, but it came to me at no cost. It proudly proclaims itself as a “Portable Oscillograph”, but requires its owner to be a weightlifter to move it. I still have it, as a relic and curio.
For most of us a new ‘scope is still a significant investment. Even affordable current models such as the extremely popular Rigol instruments are likely to cost several hundred dollars, but offer measurement functions undreamed of by those 1950s engineers who would have looked on the Cossor as an object of desire.
Oscilloscope buyers on a budget may not have the cash for a Rigol, a Hantek, or any of the other affordable ‘scopes. Someone starting on the road of electronic engineering can scout around for a cheap or free second-hand CRT model, but thanks to the ever advancing march of technology they also have another option. Modern microprocessors and microcontrollers have analogue-to-digital converters and processor cores that are fast enough to provide the functions of a simple oscilloscope, and to that end a variety of very cheap ‘scopes and ‘scope kits have come on the market. These invariably have a rather small LCD screen and a relatively low bandwidth, but since they can be had for almost pocket-money prices their shortcomings can be overlooked in the name of value. It’s been a matter of curiosity for some time then: are these instruments any good? For around £16 ($21) and the minor effort of an online order from China, we decided to find out.
If you look at most stockists of electronic kits these days, you are likely to find an oscilloscope kit in their range. These are volume produced in China, and the same design trends appear across different models. You can buy surface mount or through-hole, and most of them feature a bare board with maybe a piece of laser-cut Perspex standing in for a case. There are one or two models appearing that come with a case though, and it was one of these that we ordered. The JYE Tech DSO150 is a single-channel ‘scope with a 2.4″ 320×240 pixel colour LCD screen and a 200kHz bandwidth. Its specification is typical of the crop of similar kits, though its smart case sets it apart and made it an easy choice.
In the Box
We ordered one, and when it arrived, it was packed in a small cardboard carton that had suffered some crushing in transit, but had protected the internal contents well enough that no harm had been done. A layer of foam protected the LCD, and the case parts appeared rigid enough to protect the rest of the components. There was a bag of discretes, the case parts, two PCBs, a test lead with crocodile clips, and two pages of instructions.
When looking at a kit, it’s best to start with the instructions, because no matter the quality of the kit itself it is the quality of the instructions that make or break a kit. If you can’t build it then it doesn’t matter how good it might be, it’s effectively junk.
The DSO150 instructions are two sheets of high quality double-sided colour print, with the emphasis on pictures rather than words, The front page introduces the kit and gives a quick soldering guide, then the next two pages step through each stage of construction. The final page has basic instructions for use, specification, and a troubleshooting guide. Our kit had all surface-mount parts already fitted, if we’d known the kit could also be had with SMD parts to fit we’d have bought that version instead.
Inside the DSO100.
The instruction steps are long on images and short on text, but there are sometimes few cues as to where the component in question lies on the board. Sometimes some careful examination of board and picture is necessary to ensure correct placement. The first step though doesn’t involve any soldering, wire the main board up to a 9V supply, and watch the LCD boot into the oscilloscope software. There is support via a forum on the JYE Tech website, we presume you’d go there if it failed to boot out of the box. A 9V PSU isn’t included, you’ll need to find one with a 2.1mm centre positive plug. Fortunately a suitable candidate was in the box of wall warts here, formerly being used by a router.
The main board assembly is straightforward enough, being the assembly of larger through-hole parts such as switches and connectors. The analogue board has a brace of small through-hole resistors and ceramic capacitors to fit, of these the resistors were of the tiny variety which made distinguishing between some of their colour stripes a little difficult. Bring your multimeter to check. There is a BNC connector that requires significant heat on there too, so make sure you have a suitably beefy iron to hand. Finally there is a small board for the rotary encoder, then the front of the case can be assembled to the main board, the analogue board attached, and the ‘scope set up. Verify on-board voltages, attach the test clip to the calibration output and adjust the compensation capacitors for a square wave, and the rest of the case can be added to complete the unit.
Functionality
The DSO150 showing the upper end of its bandwidth.
In use, the DSO150 makes a simple and straightforward enough oscilloscope. The usual volts/division and timebase selection is easy enough, and the various trigger modes can quickly be selected. If you’ve used an oscilloscope before then you will have no problems getting started with it. But of course, the DSO150 isn’t just a simple oscilloscope, it’s a digital storage ‘scope. And with 1024 sampling points it can do the usual storage ‘scope thing of allowing the user to examine a stored waveform in great detail, scrolling back and forth through the stored points. Here the instruction sheet falls short, not mentioning that a double tap on the V/div or Sec/div buttons allows you to scroll.
Connecting the signal generator to our DSO150 allowed the exploration of its bandwidth. The claimed 200kHz is pretty spot-on, winding the signal generator far beyond that point showed a tail-off in displayed amplitude. Also the minimum 10µS per division limits the usefulness of a waveform display at these frequencies.
The DSO150 is supplied with a short test lead terminated in a pair of crocodile clips. This is somewhat less useful than the oscilloscope probes we’re used to, though happily it can also be used with a standard 1x/10x probe. Looking at the square wave on the test terminal through a standard probe reveals a sharp corner on the waveform, so there seems not to be any problems between the compensation on-board and that in the probe. It’s likely that either the DSO150 here will be used with a standard probe, or that the crocodile clip will swiftly be replaced with a probe of some kind.
Closing Thoughts
So then, the JYE Tech DSO150 oscilloscope kit. A nice little ‘scope within the limitations of the STM32F103C8 microcontroller that drives it. If you can put up with a 200kHz bandwidth and a 50V peak input voltage then it’s a useful pocket instrument. Its calibration will depend on the STM’s crystal and voltage reference, but as with the rest of its specification, when you consider its pocket-money price those become minor considerations. Add in that its software is open-source, and you have a very nice platform indeed. If we wanted to nitpick we’d ask for a battery compartment and a proper probe, but since both of those would put up the price we wouldn’t make too much noise about it. If you need a pocket ‘scope to supplement your bench scope when working on lower frequencies, or if you have a youngster in the family looking for their first ‘scope, buy one! Our review unit will definitely see some use rather than gathering dust.
If you look at most stockists of electronic kits these days, you are likely to find an oscilloscope kit in their range. These are volume produced in China, and the same design trends appear across different models. You can buy surface mount or through-hole, and most of them feature a bare board with maybe a piece of laser-cut Perspex standing in for a case. There are one or two models appearing that come with a case though, and it was one of these that we ordered. 
