Sanding Seashells by the Seashore

We all maintain this balancing act between the cool things we want, the money we can spend, and our free time. When the pièce de résistance is a couple of orders of magnitude out of our budget, the only question is, “Do I want to spend the time to build my own?” [Nick Charlton] clearly answered “Yes,” and documented the process for his Nautilus speakers. The speaker design was inspired by Bowers & Wilkins and revised from a previous Thingiverse model which is credited.

The sound or acoustic modeling is not what we want to focus on since the original looks like something out of a sci-fi parody. We want to talk about the smart finishing touches that transform a couple of 3D printed shells into enviable centerpieces. The first, and most apparent is the surface. 3D prints from consumer FDM printers are prone to layer lines, and that aesthetic has ceased to be trendy. Textured paint will cover them nicely and requires minimal elbow grease. Besides sand and shells go together naturally. At first glance, the tripod legs holding these speakers seemed like a classy purchase from an upscale furniture store, but they are, in fact, stained wood and ground-down bolts. Nicely done.

The moral is to work smarter, take pictures, then drop us a line.

Old Game Development IDE Goes FPGA

If you have a thing for old game development — things like the Atari 2600 or similar period arcade games — you might already know about the 8bitworkshop IDE. There you can develop code in your browser for those platforms. In a recent blog post, the site announced you can now also do FPGA development in the IDE.

According to the site:

Most computers are fast enough to render a game at 60 Hz, which requires simulating Verilog at almost 5 million ticks per second.

To activate Verilog, you need to select the hamburger menu to the top left, select Platform, and then under Hardware, check Verilog. What makes this different from, say, EDA Playground, is that the output can be waveforms or the output to a virtual TV monitor. For example, here’s one of the examples:

The Verilog code is generating horizontal and vertical sync along with an RGB output and the results appear on the monitor to the right. There is a handle at the bottom of the screen. If you drag it up you will see the logic analyzer output. Drag it down and you’ll see the screen again. The examples include an 8-bit and 16-bit CPU, and example games that can even read the mouse.

Honestly, we don’t think anyone would suggest using Verilog to write in-browser games. That isn’t really the point here. However, if you are trying to learn Verilog, it is great fun to be able to produce something other than just abstract waveforms from simulation. The only downside is that to move to a real piece of hardware, you’d need to duplicate the interfaces provided by the IDE. That would not be very hard, and — of course — if you are just using it to learn you can try a different project for the real world.

If you need help getting going in Verilog, we have a series of boot camps that can help. Those tutorials use EDA Playground, but they’d probably work here, too. If you try them in the IDE, be sure to let us know your experience.

Refurbishing A Classic Electrostatic Speaker PSU

Sometimes a project takes longer than it should to land in the Hackaday in-tray, but when we read about it there’s such gold to be found that it’s worth sharing with you our readers despite its slight lack of freshness. So it is with [Andrew Back]’s refurbishment of his Quad electrostatic speaker system power supply, it may have been published back in August but the glimpse it gives us into these legendary audio components is fascinating.

The inner workings of an electrostatic loudspeaker
The inner workings of an electrostatic loudspeaker

An electrostatic speaker is in effect a capacitor with a very large surface area, of which one plate is a flexible membrane suspended between two pieces of acoustically transparent mesh that form the other plates. A very high DC bias voltage in the multiple kilovolts region is applied across the capacitor, and the audio is superimposed upon it at a peak-to-peak voltage of somewhere under a kilovolt through a step-up transformer from the audio amplifier. There are some refinements such as that the audio is fed as a push-pull signal to the opposing mesh plates and that there are bass and treble panels with different thickness membranes, but these speakers are otherwise surprisingly simple devices.

The problem with [Andrew]’s speakers became apparent when he took a high voltage probe to them, one speaker delivered 3 kV from its power supply while the other delivered only 1 kV. Each supply took the form of a mains transformer and a voltage multiplier board, so from there it became a case of replacing the aged diodes and capacitors with modern equivalents before applying an insulating layer for safety.

Electrostatic speakers are no stranger to Hackaday, we’ve taken an in-depth look at them in the past. You may also find some of our colleague [Steven Dufresne]’s writing on the matter to be of interest, on measuring high voltages, and his experience wrangling high voltage.

Get Your Tweets Without Looking

Head-mounted displays range from cumbersome to glass-hole-ish. Smart watches have their niche, but they still take your eyes away from whatever you are doing, like driving. Voice assistants can read to you, but they require a speaker that everyone else in the car has to listen to, or a headset that blocks out important sound. Ignoring incoming messages is out of the question so the answer may be to use a different sense than vision. A joint project between Facebook Inc. and the Massachusetts Institute of Technology have a solution which uses the somatosensory reception of your forearm.

A similar idea came across our desk years ago and seemed promising, but it is hard to sell something that is more difficult than the current technique, even if it is advantageous in the long run. In 2013, a wearer had his or her back covered in vibrator motors, and it acted like the haptic version of a spectrum analyzer. Now, the vibrators have been reduced in number to fit under a sleeve by utilizing patterns. It is being developed for people with hearing or vision impairment but what drivers aren’t impaired while looking at their phones?

Patterns are what really set this version apart. Rather than relaying a discrete note on a finger, or a range of values across the back, the 39 English phenomes are given a unique sequence of vibrations which is enough to encode any word. A phenome phoneme is the smallest distinct unit of speech. The video below shows how those phonemes are translated to haptic feedback. Hopefully, we can send tweets without using our hands or mouths to upgrade to complete telepathy.

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Clever Wedges That Will Increase Your PCB Assembly Yield

If there’s one thing that will bring down the yield of your PCB assembly, it’s your solder paste. Put too much on, and you’ll get bridged leads. If you don’t put enough on, that pad might not make good contact. [ScalarElectric] has an amazing trick that’s sure to astonish and astound. Just use wedges and you’ll get better yield with fine-pitched components.

The trick here is to define the cream/solder paste layer of each package as a wedge on each pad instead of the usual rectangle. This gives a few benefits, the largest being the increased gap between paste shapes. You’re also getting a reduction in the total amount of paste applied, and a subsequent improvement in yield. (Reportedly, we’d love to see some data on this.)

PCB design tools usually have a way to alter the size of the cream/solder paste layer of a design, and indeed one option is to simply shrink the size of the paste layer elements. The trick to the wedges is increasing the total distance between solderpaste blobs while keeping the total amount of solderpaste high. This technique can be used down to 0.5mm pitch parts, and everything works like a charm.

While this is a little outside of our wheelhouse here at Hackaday — it is, after all, a novel use of existing tools that is mostly applicable to electronic design and production. [Ed Note: Sarcasm.] You can check out a few pics of this technique in the slideshow below. If you test this technique out, be sure to let us know how it went!

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Experiment With Lumia, The Cheap and Easy Way

Light is a wonderful medium for art, and there’s all manner of ways to approach it. We’ve always been huge fans of all that blinks and glows, but there’s a whole wide world of other methods and techniques in the lighting arena. Lumia is one that does not always get a lot of mainstream attention, and so [Adam Raugh] has created this video, sharing both the history of the effect, and various ways to create it yourself. 

Lumia was once used to refer to a broad swathe of artistic lighting, but these days, more commonly refers to effects that create an aurora-like appearance, as one would see near the poles of our fine Earth. [Adam] first covers the history of the effect, as pioneered by Thomas Wilfred with the Clavilux in the early part of the 20th Century.

The video then covers the basics of creating lumia effects using DIY methods. The key is to combine slow rotation with an organically deformed refractive medium. [Adam]’s rig of choice is a basic laser projector, rotating at just 1/3 of a rotation per minute. This is then combined with a variety of homebrewed refractive media – torture tubes made from glass, acrylic sheets coated with muddled epoxy, and even a crumpled water bottle.

It’s an excellent primer on how to get started with lumia, and [Adam] covers a wide variety of tips and tricks as well as potential pitfalls to avoid.

We see plenty of great lighting projects around these parts – check out the Kinetic Chandelier. Video after the break.

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Game Boy Camera – Now In Color

The Game Boy Camera is a legendary piece of 90s gaming hardware, despite not being a game at all. It consisted of a low-resolution greyscale camera, fitted to a Game Boy cartridge, that you could use to photograph your friends, vandalise their pictures, then print them out on a thermal printer. It’s hardware that was fun because of its limitations, not despite them. However, [Matt] wondered if there was a way to use early photographic techniques to get color photos.

The technique is simple – get red, green, and blue filters, and take three photos – one using each filter. Then, combine the photos digitally to create the color image.  This necessitates an amusingly complex process to transfer the photos from Game Boy to PC, of course.

There are some limitations – due to the speed of the Game Boy Camera, it works best with static scenes, as it takes several seconds to shoot. Also, due to the low resolution, it’s best to choose subjects with broad swathes of color. Despite this, [Matt] managed to take some great images with a colorful yet vintage digital charm. There’s other ways to achieve this, of course – like bringing the power of neural networks to bear on your low-res Game Boy images. Video after the break.

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