classic hacks

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Sound-Triggered Eye Protection For The Forgetful Among US

February 8, 2019 by 21 Comments

Eyes are fragile things. They tend to fail under extreme heat, pressure, and are easily damaged by flying objects. Enterprising humans have developed a wide range of eye protection solutions, but most only work when the user remembers to put them on. [gocivici] had just such a problem, forgetting to put his safety glasses back on when working. Naturally, the solution was found through hacking.

The build starts with a regular baseball cap. [gocivici] fitted an Arduino nano, which is connected to a small microphone. The Arduino uses the microphone to determine the sound level in the room. Above a certain trigger level, the Arduino triggers a servo to move protective glasses into place in front of the wearer’s eyes, protecting them from flying shrapnel from whatever they may be working on.

It’s a fun build, that obviously still has the pitfall that you’re going to get hurt if you forget to wear your magic hat for the day. Another approach could be putting your multimeter display in your goggles so you never want to take them off in the first place. Video after the break.

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State Of The Art Big Mouth Alexa Bass

February 7, 2019 by 9 Comments

Hackers seem intent on making sure the world doesn’t forget that, for a brief shining moment, everyone thought Big Mouth Billy Bass was a pretty neat idea. Every so often we see a project that takes this classic piece of home decor and manages to shoehorn in some new features or capabilities, and with the rise of voice controlled home automation products from the likes of Amazon and Google, they’ve found a new ingredient du jour when preparing stuffed bass.

[Ben Eagan] has recently completed his entry into the Pantheon of animatronic fish projects, and while we’ll stop short of saying the world needed another Alexa-enabled fish on the wall, we’ve got to admit that he’s done a slick job of it. Rather than trying to convince Billy’s original electronics to play nice with others, he decided to just rip it all out and start from scratch. The end result is arguably one of the most capable Billy Bass updates we’ve come across, if you’re willing to consider flapping around on the wall an actual capability in the first place.

The build process is well detailed in the write-up, and [Ben] provides many pictures so the reader can easily follow along with the modification. The short version of the story is that he cuts out the original control board and wires the three motors up to an Arduino Motor Driver Shield, and when combined with the appropriate code, this gives him full control over Billy’s mouth and body movements. This saved him the trouble of figuring out how to interface with the original electronics, which is probably for the better since they looked rather crusty anyway.

From there, he just needed to give the fish something to get excited about. [Ben] decided to connect the 3.5 mm audio jack of an second generation Echo Dot to one of the analog pins of the Arduino, and wrote some code that can tell him if Amazon’s illuminated hockey puck is currently yammering on about something or not. He even added a LM386 audio amplifier module in there to help drive Billy’s original speaker, since that will now be the audio output of the Dot.

A decade ago we saw Billy reading out Tweets, and last year we presented a different take on adding an Alexa “brain” to everyone’s favorite battery powered fish. What will Billy be up to in 2029? We’re almost too scared to think about it. Continue reading “State Of The Art Big Mouth Alexa Bass” →

Piezoelectric Gyro Shows How They Rolled Back In The Day

February 7, 2019 by 4 Comments

There’s no doubting the wonders that micro-electromechanical systems (MEMS) technology have brought to the world. With MEMS chips, your phone can detect the slightest movement, turning it into a sensitive sensor platform that can almost anticipate what you’re going to do next. Actually, it’s kind of creepy when you think about it.

But before nano-scale MEMS inertial sensing came along, lots of products needed to know their ups from their downs, and many turned to products such as this vibrating piezoelectric gyroscope that [Kerry Wong] found in an old camcorder. The video below shows a teardown of the sensor, huge by MEMS standards but still a marvel of micro-engineering. The device is classified as a Coriolis vibratory gyroscope (CVG) which, as the name implies, uses the Coriolis effect to sense rotation. In this device, [Kerry] found that a long, narrow piezoelectric element spans the long axis of the sensor, suspended from what appears to be four flexible arms. [Kerry] probed the innards of the sensor while powered up and discovered a 22 kHz signal on the piezo element; this vibrates the bar in one plane so that when it rotates, it exerts a force on the support arms that can be detected. Indeed, [Kerry] hooked the output of the sensor to a wonderfully old-school VOM whose needle wiggled with the slightest movement of the sensor.

Sadly, MEMS made this kind of sensor obsolete, but we appreciate the look under the hood. And really, MEMS chips are using the same principle to detect motion, just on a much smaller scale. Want the MEMS basics? [Al] has you covered.

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Open Source LIDAR Lets You Get Down To The Nitty Gritty

February 6, 2019 by 11 Comments

If you’re unfamiliar with LIDAR, you might have noticed it sounds a bit like radar. That’s no accident – LIDAR is a backronym standing for “light detection and ranging”, the word having initially been created as a combination of “light” and “radar”. The average person is most likely to have come into contact with LIDAR at the business end of a police speed trap, but it doesn’t have to be that way. Unruly is the open source LIDAR project you’ve been waiting for all along.

Unlike a lot of starter projects, LIDAR isn’t something you get into with a couple of salvaged LEDs and an Arduino Uno. We’re talking about measuring the time it takes light to travel relatively short distances, so plenty of specialised components are required. There’s a pulsed laser diode, and a special hypersensitive avalanche photodiode that operates at up to 130 V. These are combined with precision lenses and filters to ensure operation at the maximum range possible. Given that light can travel 300,000 km in a second, to get any usable resolution, a microcontroller alone simply isn’t fast enough to cut it here. A specialized  time-to-digital converter (TDC) is used to time how long it takes the light pulse to return from a distant object. Unruly’s current usable resolution is somewhere in the ballpark of 10 mm – an impressive feat.

It’s a complicated project, requiring the utmost attention to detail to get any results at all. The team behind Unruly have done a great job of both designing and documenting the project. It’s great to see an open source LIDAR package in the wild, giving hackers more options than just the pre-baked commercial modules on the market. We can’t wait to see where the project goes next.

For more on LIDAR, check out last week’s Hackaday podcast – we cover Unruly, as well as a handful of other standout projects in the field.

Fail Of The Week: Electromigration Nearly Killed This Xerox Alto

February 3, 2019 by 51 Comments

The Living Computers museum in Seattle has a Xerox Alto, the machine famous for being the first to sport a mouse-based windowing graphical user interface. They received it in working condition and put it in their exhibit, but were dismayed when a year later it ceased to operate. Some detective work revealed that the power supply was failing to reach parts of the machine, and further investigation revealed an unlikely culprit. Electromigration had degraded the contacts between the supply pins and the backplane traces.

If electromigration is new to you, don’t feel ashamed, it was a new one to us too. It’s “the transport of material caused by the gradual movement of the ions in a conductor due to the momentum transfer between conducting electrons and diffusing metal atoms“, got it? Okay, that’s just a long way to say that passing a sufficiently high current through a conductor for a long time can physically move the metal of that conductor.

This one just doesn’t pop up very often. But in the case of the Alto, an under-specified power distribution system caused a lot of current to flow through too few solder joints. Those joints were left without enough metal to make a decent connection, so they failed.

The fix came with a set of sturdy busbars freshly soldered to the pins, but the interest in this piece comes more from the unusual phenomenon that caused it. That soldered joints can seemingly flow away defies belief. It’s still something most of us will never encounter, but like tales of ball lightning it’s one for the “Fancy that!” collection.

We’ve covered the Alto before, most notably [Ken Shirriff]’s work in restoring the Computer History Museum’s example.

Blacksmith Elevates The Craft With This Fabulous Strongbox

February 3, 2019 by 35 Comments

For most of human industrial history, the blacksmith was the indispensable artisan. He could fashion almost anything needed, from a simple hand tool to a mechanism as complex as a rifle. Starting with the most basic materials, a hot forge, and a few tools that he invariably made himself, the blacksmith was a marvel of fabrication.

If you have any doubt how refined the blacksmith’s craft can be, feast your eyes on [Seth Gould]’s masterpiece of metalwork. Simply called “Coffer”, [Seth] spent two years crafting the strongbox from iron, steel, and brass. The beautifully filmed video below shows snippets of the making, but we could easily watch a feature-length film detailing every aspect of the build. The box is modeled after the strongboxes built for the rich between the 17th and 19th centuries, which tended to favor complex locking mechanisms that provided a measure of security by obfuscation. At the end of the video below, [Seth] goes through the steps needed to unlock the chest, each of which is filled with satisfying clicks and clunks as the mechanism progresses toward unlocking. The final reveal is stunning, and shows how much can be accomplished with a forge, some files, and a whole lot of talent.

If you’ve never explored the blacksmith’s art before, now’s the time. You can even get started easily at home; [Bil Herd] will show you how.

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Microwave Parts Become Quick And Nasty Jacob’s Ladder

February 2, 2019 by 20 Comments

The Jacob’s Ladder is an electrical device named after a biblical “ladder to Heaven”, consisting of a pair of vertically oriented conductors that spread apart vertically. These conductors are charged with high voltage, which creates the repeatedly climbing arc we’ve all come to know and love from science fiction movies of yesteryear.

[LOOK MUM NO COMPUTER] was on a scavenger hunt for electronic junk, and came across a microwave in a skip that was begging to be hacked. After kicking around a few ideas, it was decided that the microwave would donate its high voltage transformer to create a Jacob’s ladder. The transformer is first bolted down to a piece of wood, and creates some sparks on the bench when shorted. The output is then wired to a pair of copper pipes to create the classic effect.

Unfortunately, the device isn’t self starting, requiring the electrodes to be temporarily short circuited to generate the initial arc. We suspect that increasing the voltage may help things somewhat, either with another transformer in series or with a voltage multiplier.

It goes without saying that high voltage projects do bring certain risks to life and limb that should not be overlooked. If you’ve still got a thirst for danger, check out this home built X-ray machine. Video after the break.

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