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1347 Articles

Hot Glue Makes These Segments Glow

January 13, 2019 by 14 Comments

It’s safe to say that hot-melt glue is a staple of the projects we see here at Hackaday. There won’t be many readers who don’t have a glue gun, and a blob of the sticky stuff will secure many a project. But it’s not so often we see it used as an integral component for a property other than its stickiness, so [DusteD]’s reaction timer project is interesting for having hot glue as a translucent light guide and diffuser for its LED seven-segment display.

The timer is simple enough, being driven by an Arduino board, while the display is pre-formed into the 3D-printed case. The hot glue fills the enclosures behind each segment, and after several experiments it was found that the best filling method was from behind against a piece of Kapton tape. The LEDs were wired into a common cathode array, and along with the arcade-style button and the Arduino the whole fitted neatly in the box. You can see the result in action in the video below the break.

Of course, this display is unusual for its use of hot glue, but not unique. We’ve seen a different take on a hot glue light pipe display before.

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Addressable 7-Segment Displays May Make Multiplexing A Thing Of The Past

January 12, 2019 by 52 Comments

[Sean Hodgins] has a knack for coming up with simple solutions that can make a big difference, but this is one of those “Why didn’t I think of that?” things: addressable seven-segment LED displays.

[Sean]’s design is basically a merging of everyone’s favorite Neopixel RGB LED driver with the ubiquitous seven-segment display. The WS2811 addressable RGB driver chip doesn’t necessarily have to drive three different color LEDs – it can drive three segments of the same display. With three of the chips on a single board, all seven segments plus the decimal point of a display can be controlled over a single data line. No more shift registers, no more multiplexing. And as a nice touch, individual displays can be ganged together with connectors on the back of each module. [Sean] has some code to support the display but is looking for someone to build a standalone library for it, so you might want to pitch in. Yes, he plans to sell the boards in his shop, but as with all his projects, this one is open source and everything you need to build your own is up on GitHub. The brief video below shows a few daisy-chained displays in action.

Like many of [Sean]’s designs, including this Arduino rapid design board, this is a simple way to get a tedious job done, and it wrings a lot of functionality from a single IO pin.

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Visual Airplane Tracker Runs On Pi

January 11, 2019 by No comments

As no doubt is the case with many readers, there is a Raspberry Pi running in the yard near where this is being written that tracks airplanes, listening into the ADS-B radio broadcasts that they send and uploading the data to a sharing service. This device lacks the blinky LEDs that hacking custom states it should have, though. This project from [xy72y5e] would be a great way to deal with that problem: they used a Unicorn hat to create a simple map of local airplanes. This shows the location and track of aircraft in the area on the 8 by 8 RGB LED matrix of the Unicorn Hat.

While the device here maps local planes from their radio fixes, the code that [xy72y5e] published works with the api of ADSBExchange, a site that shares flight data. This means that the map can be easily set to show air traffic at a different location to the device itself. And it wouldn’t be that difficult to alter this to show the locally detected planes, as [xy72y5e] has published the full Python code that creates the map. This would also go well with some of the other airplane tracking hacks that we’ve seen recently, such as the planespotter destination tracker or tracking airplanes by radar reflections…

[Via Reddit]

WiFi Remote Control Those Cheap LED Strips With An ESP8266 Passthrough

January 9, 2019 by 23 Comments

The explosion of cheap LED lighting products has given a never-ending array of opportunities for the resourceful hacker. A few dollars can secure strings of colourful illumination, but without further expenditure they lack the extra utility of electronic control. This is something that [Albert David has addressed] with his simple ESP8266-based WiFi switcher that he’s added to a string of USB-powered LEDs, and he’s neatly mounted the ESP-12 module it used atop a USB plug.

The circuitry is pretty straightforward, with only a couple of I/O lines being used. A transistor takes care of the heavy lifting, and the software comes courtesy of the Tasmota firmware for Sonoff (and similar) devices. We suspect with this economy of connection, the same task could be achieved even with the limited resources provided by the lesser ESP-01 module.

There was a time not so long ago when performing a task such as controlling a light over a wireless network involved significant cost, power, and complexity. In the nearly five years since we reported on the arrival of the ESP8266 we have progressed to the point at which that task is a simple project using commodity components, and that represents something of a miracle.

A Foggy Lightsaber Build

January 4, 2019 by 5 Comments

Lightsabers have enchanted audiences since their appearance in the very first Star Wars film in 1977. Unfortunately, George Lucas hasn’t shared the technology in the years since then with the broader public, so we’re left to subsist on pale imitations. This is just such a build.

The closest human analog to Jedi technology is the laser, and this build uses 8 of them in combination with two LEDs. They’re aimed to coincide at a fixed distance above the hilt. A CO2 bicycle inflater is then used to blow through an e-cigarette to create a fog. This makes the red lasers readily visible to the human eye.

This ersatz lightsaber does have its limitations – fast motion tends to scatter the fog, making it once again invisible, and it’s really at its best held in a vertical orientation. There’s also some divergence beyond the focused point. With that said, it does look somewhat impressive when held still, smouldering away.

Until we gain a better mastery of plasma physics, perhaps you can make do with this fire-based build? Video after the break.

[Thanks to qrp-gaijin for the tip!]

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Fail Of The Week: EPROMs, Rats’ Nests, Tanning Lamps, And Cardboard On Fire

January 2, 2019 by 87 Comments

It all started when I bought a late-1990s synthesizer that needed a firmware upgrade. One could simply pull the ROM chip, ship it off to Yamaha for a free replacement, and swap in the new one — in 2003. Lacking a time machine, a sensible option is to buy a pre-programmed aftermarket EPROM on eBay for $10, and if you just want a single pre-flashed EPROM that’s probably the right way to go. But I wanted an adventure.

Spoiler alert: I did manage to flash a few EPROMs and the RM1X is happily running OS 1.13 and pumping out the jams. That’s not the adventure. The adventure is trying to erase UV-erasable EPROMS.

And that’s how I ended up with a small cardboard fire and a scorched tanning lamp, and why I bought a $5 LED, and why I left EPROMs out in the sun for four days. And why, in the end, I gave up and ordered a $15 EPROM eraser from China. Along the way, I learned a ton about old-school UV-erasable EPROMs, and now I have a stack of obsolete silicon that’s looking for a new project like a hammer looks for a nail — just as soon as that UV eraser arrives in the mail.

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Infinity Cube Is Gorgeous Yet Simple

December 29, 2018 by 23 Comments

Typically when we hear the words “LED” and “Cube”, we think of small blinking devices on protoboard designed to flex one’s programming and soldering skills. However, while [Heliox]’s Cube Infini could be described as “a cube of LEDs”, it’s rather a different beast (video in French, subtitles available).

The cube starts with a 3D printed frame, designed in Fusion 360. The devil really is in the details — [Heliox] puts in nice touches, such as the artistic cube relief on the base, and the smart integrated cable management in the edges. The faces of the cube are plexiglass sheets, covered with a one-way reflective film that is applied in a similar manner to automotive window tint. For lighting, a high-density LED strip is fitted to the inside edges, chosen for maximum visual effect. It’s controlled by an IR remote and a cheap control module from Amazon.

While the build contains no particularly advanced tools, materials, or techniques, the final result is absolutely stunning. It’s a piece we’d love to have as a lamp in a stylish loungeroom or study. [Heliox] does a great job of explaining how the cube is designed and fits together, and it’s a testament to just what can be achieved with a little ingenuity and hard work.

Once you’re done here, check out this ping-pong based build.

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