Review: Ear Wax Cleaning Cameras As Cheap Microscopes, We Take A Closer Look

November 11, 2019 by Jenny List 50 Comments

Those of us who trawl the world of cheap imported goods will most often stay in our own comfortable zones as we search for new items to amaze and entertain us. We’ll have listings of electronic goods or tools, and so perhaps miss out on the scores of other wonders that can be ours for only a few dollars and a week or two’s wait for postage.

Who knew sticky ears were such big business!

Just occasionally though something will burst out of another of those zones and unexpectedly catch our eye, and we are sent down an entirely new avenue in the global online supermarket.

Thus it was that when a few weeks ago I was looking for an inspection camera I had a listing appear from the world of personal grooming products. It seems that aural hygiene is a big market, and among the many other products devoted to it is an entire category of ear wax removal tools equipped with cameras. These can get you up close and personal with your ear canal, presumably so you can have a satisfying scoop at any accumulated bodily goop. I have a ton of electronics-related uses for a cheap USB close-up camera so I bought one of these so I could — if you’ll excuse the expression — get a closer look.

Continue reading “Review: Ear Wax Cleaning Cameras As Cheap Microscopes, We Take A Closer Look” →

New Part Day: Alexa Connect Kit Now Available For Sale

November 11, 2019 by Maya Posch 8 Comments

People who were subscribed to updates on the Alexa Connect Kit (ACK) would recently have received an email informing that this kit is now available for sale. Last time we covered the ACK was back in September of 2018, the ‘release’ moniker meant ‘preview’ and there wasn’t any hardware one could actually purchase.

Over a year a later it seems that we can now finally get our grubby mitts on this kit that should enable us to make any of our projects Alexa-enabled. What this basically seems to mean is that one can spend close to 200 US dollars on an Arduino Zero and an Arduino shield-mounted WM-BN-MT-52 module from USI (though not listed on their site, but similar to the WM-BN-BM-22?) that integrates a 192 MHz Cortex-M MCU and a WiFi/Bluetooth module, as summarized on the Amazon Developer page for the ACK.

Continue reading “New Part Day: Alexa Connect Kit Now Available For Sale” →

Network Booting The Pi 4

November 11, 2019 by Jonathan Bennett 106 Comments

We’ve talked about PXE booting the Raspberry Pi 3B+, and then looked at the Raspberry Pi 4 as a desktop replacement. But there’s more! The Pi 4 sports a very useful new feature, the flashable bootloader. Just recently a beta version of that bootloader was released that supports PXE — booting up over the network — which has become a must-have for those of us who have had consistently bad experiences with root filesystems on SD cards.

What are the downsides, I hear you ask? You might see slower speeds going across the network compared to a high quality SD card, particularly with the Pi 4 and its improved SD card slot. PXE does require an Ethernet cable; WiFi is not enough, so you have that restriction to contend with. And finally, this isn’t a portable option — you are tethered to that network cable while running, and tethered to your network to boot at all.

On the other hand, if you’re doing a permanent or semi-permanent install of a Pi, PXE is absolutely a winner. There are few things worse than dragging a ladder out to access a Pi that’s cooked its SD card, not to mention the possibility that you firewalled yourself out of it. Need to start over with a fresh Raspbian image? Easy, just rebuild it on the PXE server and reboot the Pi remotely.

Convinced PXE is for you? Let’s get started! Continue reading “Network Booting The Pi 4” →

Mechanical Seven-Segment Display Mixes Art With Hacking

November 11, 2019 by Dan Maloney 28 Comments

We’re not sure what to call this one. Is it a circuit sculpture? Sort of, but it moves, so perhaps it’s a kinetic circuit sculpture. Creator [Tomohiro Tsuchita] calls it “something beautiful but totally useless,” which we find a tad harsh. But whatever you call it, we think this mechanical seven-segment display is really, really cool.

Before anyone gets to thinking that this is something like the other mechanical seven-segment displays we’ve seen lately, think again. This one is not addressable; it simply goes through the ten digits in order. So you won’t be building a clock from it, although we suppose the mechanism could be modified to allow that. Then again, looking at that drive train of laser-cut acrylic cams, maybe not. Each segment has its own cam with lobes or valleys for each segment. A cam follower lowers and raises the segments as the cams rotate on a common shaft. A full-rotation servo powers the display under the control of a Micro:bit; the microcontroller is overkill for now but will be used in version two, which will allow the speed to change in response to sensors.

Watching this display change at its stately pace is strangely soothing. We love the look of this, but then again, we’re partial to objets d’art-circuit. After all, we ran a circuit sculpture contest earlier in the year, and just wrapped up a Hack Chat dedicated to the subject.

Continue reading “Mechanical Seven-Segment Display Mixes Art With Hacking” →

LCD Panel Lamp Shade Makes For Eye-Catching Lighting

November 11, 2019 by Jenny List 14 Comments

At first sight, [Kyle]’s Elroy lamp is simply an attractive piece of modern-styled interior furnishing; its clean lines, wood grain, and contemporary patterning being an asset to the room. But when he pulls out his phone, things change. Because this lamp hides a secret: at its heart may be a standard LED bulb, but the shade conceals four LCD screens driven by an Nvidia Jetson. These can be controlled through a web app to display a variety of textures, completing the effect.

This is not however simply a set of laptop screens bolted to a lampshade. The screens started life in laptops sure enough, but have since had their reflective backing removed to create a transparent LCD panel. Then an appropriate diffuser had to be found, which after much experimentation became a composite including more than one textured paper. Finally the whole was enclosed in an attractive wooden lamp frame and became part of the furniture. We like it, both as an aesthetically pleasing lamp and as a genuine departure from the norm.

This isn’t the first eye-catching lampshade we’ve brought you, but it’s certainly raised the bar. You can see it in action in the video below the break.

Continue reading “LCD Panel Lamp Shade Makes For Eye-Catching Lighting” →

Time Sync Through Your VGA Connector

November 10, 2019 by Jenny List 16 Comments

While it might be in its twilight years, the venerable VGA video connector conceals a versatile interface that can still provide the experimenter with the opportunity for a variety of hacks. We’ve not seen anything quite like [flok]’s one, in which he uses the VGA interface to insert timing information from which an NTPd instance gets its reference.

If this seems counter-intuitive because a VGA interface is an analogue output rather than a digital input, then you are correct to smell a rat. And he comes clean in his first sentence, as he’s not using the VGA lines themselves but the I²C interface that is a feature of all but the most basic of VGA cards. This is the means by which a plug-and-play operating system can identify a monitor’s capabilities, but there’s little to stop it being used for other purposes. In this case an Arduino fed by a 1-pulse-per-second timing signal from a temperature compensated crystal oscillator provides the I²C peripheral which is polled by NTPd.

This project should be of interest to any tinkerer because of its invaluable information on identifying and using the I²C interface on a VGA socket. So if you’ve used your VGA card as an SDR you might find it interesting, but hurry or you could have missed the boat entirely.

VGA plug image: Swift.Hg [CC BY-SA 3.0]

DIY Electrolysis Tank: Removing Rust While You Sleep

November 10, 2019 by Danie Conradie 41 Comments

Anyone who’s done a bit of metalworking will know how quickly your stockpile will pick up a coating of rust with even just a bit of humidity. While welding requires only a bit of wire brushing at the joint areas, cleaning a large frame for paint is a completely different story. The projects [Make it Extreme] gets himself into tend to involve a lot of steel, so he built his own electrolysis tank for rust removal.

Electrolytic rust removal involves placing the piece of steel to be cleaned into an alkaline electrolyte solution (water and washing soda) with a sacrificial steel anode and connecting a low voltage DC supply over the two pieces. [Make it Extreme] started with an old plastic container, around which he built a very neat trolley frame. He obviously put some thought into how the tank will be cleaned, since it can be removed by unscrewing six bolts and removing the top part of the frame.

The high current, low voltage power supply that is required for the process was built using an old microwave transformer. The secondary coil is removed and replaced with coil of thick insulated wire, to convert it into a step down transformer. After the rewinding the transformer outputs about 13 VAC, which is then run through beefy bridge rectifier modules to get a DC current. A custom machined copper bolt terminal is mounted through the side of the tank to attach the sacrificial anode plate to the positive lead of the power supply, while the negative lead is clamped to the rusty steel to be cleaned.

[Make it Extreme]’s projects never get old, with everything from rideable tank tracks to rotary electric guns. Check out the video after the break to see the build and an impressive demo. Continue reading “DIY Electrolysis Tank: Removing Rust While You Sleep” →