Motorized Stage Finesses The Microscopic World

May 19, 2018 by 12 Comments

No matter how fine your fine motor skills may be, it’s really hard to manipulate anything on the stage of a microscope with any kind of accuracy. One jitter or caffeine-induced tremor means the feature of interest on the sample you’re looking at shoots off out of the field of view, and getting back to where you were is a tedious matter of trial and error.

Mechanical help on the microscope stage is nice, and electromechanical help is even better, but a DIY fully motorized microscope stage with complete motion control is the way to go for the serious microscopist on a budget. Granted, not too many people are in [fabiorinaldus]’ position of having a swell microscope like the Olympus IX50, and those that do probably work for an outfit that can afford all the bells and whistles. But this home-brew stage ticks off all the boxes on design and execution. The slide is moved across the stage in two dimensions with small NEMA-8 steppers and microstepping controllers connected to two linear drives that are almost completely 3D-printed. The final resolution on the drives is an insane 0.000027344 mm. An Arduino lives in the custom-built control box and a control pad with joystick, buttons, and an OLED display allow the stage to return to set positions of interest. It’s really quite a build.

We’ve featured a lot of microscope hacks before, most of them concerning the reflective inspection scopes we all seem to covet for SMD work. But that doesn’t mean we haven’t shown love for optical scopes before, and electron microscopes have popped up a time or two as well.

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One-key Keyboard Is Exercise In Sub-millimeter Design

May 19, 2018 by 15 Comments

As [Glen] describes it, the only real goal in his decision to design his single-key USB keyboard was to see how small he could build a functional keyboard using a Cherry MX key switch, and every fraction of a millimeter counted. Making a one-key USB keyboard is one thing, but making it from scratch complete with form-fitting enclosure that’s easy to assemble required careful design, and luckily for all of us, [Glen] has documented it wonderfully. (Incidentally, Cherry MX switches come in a variety of qualities and features, the different models being identified by their color. [Glen] is using a Cherry MX Blue, common in keyboards due to its tactile bump and audible click.)

[Glen] steps though the design challenges of making a device where seemingly every detail counts, and explains problems and solutions from beginning to end. A PIC16F1459, a USB micro-B connector, and three capacitors are all that’s needed to implement USB 2.0, but a few other components including LED were added to help things along. The enclosure took some extra care, because not only is it necessary to fit the board and the mounted components, but other design considerations needed to be addressed such as the depth and angle of the countersink for the screws, seating depth and clearance around the USB connector, and taking into account the height of the overmold on the USB cable itself so that the small device actually rests on the enclosure, and not on any part of the cable’s molding. To top it off, it was also necessary to adhere to the some design rules for minimum feature size and wall thicknesses for the enclosure itself, which was SLS 3D printed in nylon.

PCB, enclosure, software, and bill of materials (for single and triple-key versions of the keyboard) are all documented and available in the project’s GitHub repository. [Glen] also highlights the possibility of using a light pipe to redirect the embedded LED to somewhere else on the enclosure; which recalls his earlier work in using 3D printing to make custom LED bar graphs.

Parallel Programming For FPGAs

May 19, 2018 by 12 Comments

One of the best features of using FPGAs for a design is the inherent parallelism. Sure, you can write software to take advantage of multiple CPUs. But with an FPGA you can enjoy massive parallelism since all the pieces are just hardware. Every light switch in your house operates in parallel with the others. There’s a new edition of a book, titled Parallel Programming for FPGAs that explores that topic in depth and it is under the Creative Commons license. In particular, the book focuses on using Vivado HLS instead of the more traditional Verilog or VHDL.

HLS allows a designer to express a high-level algorithm in C, C++, or SystemC. Given a bit more information, HLS will convert that into an FPGA configuration. That doesn’t mean, though, that you can just cut and paste ordinary C code. HLS has several restrictions due to the fact that it is compiling to logic gates, not lines of code. Actually, it also generates Verilog or VHDL, but if you do it right, that should be transparent to you.

After the introduction, the book is more like a series of monographs on very specific topics, but the depth of each is very impressive. There’s plenty of DSP examples, of course. There’s also general math, so if you ever wondered how to compute a sine or cosine in an FPGA, read chapter 3.

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Nuclear Synchroscope Gets New Life

May 18, 2018 by 11 Comments

The Synchroscope is an interesting power plant instrument which doubles up as two devices in one. If the generator frequency is not matched with the grid frequency, the rotation direction of the synchroscope pointer indicates if the frequency (generator speed) needs to be increased or decreased. When it stops rotating, the pointer angle indicates the phase difference between the generator and the grid. When [badjer1] [Chris Muncy] got his hands on an old synchroscope which had seen better days at a nuclear power plant control room, he decided to use it as the enclosure for a long-pending plan to build a Nixie Tube project. The result — an Arduino Nixie Clock and Weather Station — is a retro-modern looking instrument which indicates time, temperature, pressure and humidity and the synchroscope pointer now indicates atmospheric pressure.

Rather than replicating existing designs, he decided to build his project from scratch, learning new techniques and tricks while improving his design as he progressed. [badjer1] is a Fortran old-timer, so kudos to him for taking a plunge into the Arduino ecosystem. Other than the funky enclosure, most of the electronics are assembled from off-the-shelf modules. The synchroscope was not large enough to accommodate the electronics, so [badjer1] had to split it into two halves, and add a clear acrylic box in the middle to house it all. He stuck in a few LEDs inside the enclosure for added visual effect. Probably his biggest challenge, other than the mechanical assembly, was making sure he got the cutouts for the Nixie tubes on the display panel right. One wrong move and he would have ended up with a piece of aluminum junk and a missing face panel.

Being new to Arduino, he was careful with breaking up his code into manageable chunks, and peppering it with lots of comments, for his own, and everyone else’s, benefit. The electronics and hardware assembly are also equally well detailed, should anyone else want to attempt to replicate his build. There is still room for improvement, especially with the sensor mounting, but for now, [badjer1] seems pretty happy with the result. Check out the demo video after the break.

Thanks for the tip, [Chris Muncy].

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Hybrid Bench Power Supply Can Also Hit The Road

May 18, 2018 by 4 Comments

Everyone needs a bench power supply, and rolling your own has almost become a rite of passage for hackers. For a long time, the platform of choice for such builds seemed to be the ATX power supply from a computer. While we certainly still see those builds, a lot of the action has switched to those cheap eBay programmable DC-DC converters, with their particolored digital displays.

This hybrid bench and portable power supply is a good example of what can be accomplished with these modules, and looks like it might turn out to be a handy tool. [Luke] centered his build around the DPS3003, a constant current and constant voltage buck converter that can take up to 40-VDC input and outputs up to 32 volts at 3 amps. In bench mode, the programmable module is fed from a mains-powered 24-volt switching supply. For portable work, an 18-volt battery from a Makita drill slips into a 3D-printed adapter on the top of the case. The printed part contains a commercial terminal [Luke] scored on eBay, but we’d bet the entire thing could be 3D printed. And no problem if you change power tool brands — just print another adapter.

Those little eBay power supply modules have proven to be an enabling technology, at least judging by the number of clever ways we’ve seen them used lately. From this combination bench PSU and soldering iron supply to a portable PSU perched atop a battery, these things are everywhere. Heck, you can even reflash the firmware and make them do your bidding.

[via Dangerous Prototypes]

Modular Blocks Help Fight Disease

May 18, 2018 by 3 Comments

When engineering a solution to a problem, an often-successful approach is to keep the design as simple as possible. Simple things are easier to produce, maintain, and use. Whether you’re building a robot, operating system, or automobile, this type of design can help in many different ways. Now, researchers at MIT’s Little Devices Lab have taken this philosophy to testing for various medical conditions, using a set of modular blocks.

Each block is designed for a specific purpose, and can be linked together with other blocks. For example, one block may be able to identify Zika virus, and another block could help determine blood sugar levels. By linking the blocks together, a healthcare worker can build a diagnosis system catered specifically for their needs. The price tag for these small, simple blocks is modest as well: about $0.015, or one and a half cents per block. They also don’t need to be refrigerated or handled specially, and some can be reused.

This is an impressive breakthrough that is poised to help not only low-income people around the world, but anyone with a need for quick, accurate medical diagnoses at a marginal cost. Keeping things simple and modular allows for all kinds of possibilities, as we recently covered in the world of robotics.

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Tiny Transmitter Brings Out The Spy Inside You

May 18, 2018 by 10 Comments

When it comes to surveillance, why let the government have all the fun? This tiny spy transmitter is just the thing you need to jumpstart your recreational espionage efforts.

We kid, of course — you’ll want to stay within the law of the land if you choose to build [TomTechTod]’s diminutive transmitter. Barely bigger than the 337 button cell that powers it, the scrap of PCB packs a fair number of surface mount components, most in 0201 packages. Even so, the transmitter is a simple design, with a two transistor audio stage amplifying the signal from the MEMS microphone and feeding an oscillator that uses a surface acoustic wave (SAW) resonator for stability. The bug is tuned for the 433-MHz low-power devices band, and from the video below, it appears to have decent range with the random wire antenna — maybe 50 meters. [TomTechTod] has all the build files posted, including Gerbers and a BOM with Digikey part numbers, so it should be easy to make one for your fieldcraft kit.

If you want to dive deeper into the world of electronic espionage, boy, have we got you covered. Here’s a primer on microphone bugs, a history of spy radios, or how backscatter was used to bug an embassy.

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