Light The Way To Every Component

January 26, 2020 by Jenny List 47 Comments

How do you organize your stock of components and modules? If an unruly pile of anti-static bags and envelopes from China stuffed into a cardboard box sounds familiar, then you need help from [Dimitris Tassopoulos]. He’s organized his parts into drawers and created a database, then linked it via an ESP8266 and a string of addressable LEDs to light up the individual drawer in which any given component resides. It’s a genius idea, as you can see in action in the video below the break.

Behind the scenes is a web server sitting atop an SQL database, with a PHP front end. It’s running on a Banana Pi board, but it could just as easily be running on any other similar SBC. The ESP8266 has a REST API to which the webserver connects when a component is sought, and from that it knows which LED to light.

The LED strip is not the tape with which most readers will be familiar, but a string of the type we might be more used to as Christmas lights. These have a 100mm spacing between LEDs, allowing them to be easily positioned behind each drawer. The result is a very effective parts inventory system. We’re not entirely sure that it would entirely banish the tide of anti-static bags here, but we’re impressed nevertheless.

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Bask In The Glory Of This 336 LED Digit Display

January 18, 2020 by Tom Nardi 12 Comments

[Chris Combs] recently took the wraps off of an incredible art piece that he calls Road Ahead which uses 336 seven segment LED digits to create an absolutely gorgeous display. With a piece of smoked acrylic to slightly diffuse the orange glow of the LEDs, the end result has a distinctively retro look that we’d gladly spend all day staring at.

For those looking to dig a bit deeper, [Chris] has put together some very impressive documentation over on Hackaday.io that goes into plenty of detail on how he designed and built this beauty. From the design of the PCBs that carry all of the 0.3″ SMD displays to the custom software running on the Raspberry Pi 3 that powers it, there’s no technical stone left unturned.

According to the build log, this is the second version of the display. The first one was housed in a rather attractive wooden enclosure, but as [Chris] explains, that was precisely the problem. He wanted something that looked cold and unfeeling as the nearly 340 digits flashed away with potentially ominous intent. So he ditched the wooden case for a powder coated steel one that looks more like the front panel of a mainframe than something you’d pick up at the craft store.

Another interesting point explained in the write-up is how the Python software is designed to treat the hardware as a contiguous graphical display rather than just an array of independent digits. Grayscale images can be reproduced on the by using PWM to adjust the brightness of each segment’s corresponding “pixel”; though admittedly it takes a bit of imagination to see the intended image with a resolution this low.

This project reminds us of the incredible LED hexdump display we saw not that long ago, down to the PWM trickery for squeezing “graphics” out of these exceptionally non-graphical elements. With any luck, perhaps these are the opening shots in an arms race to see who can build the largest array of multi-segment LED displays.

A Strange Display Gives Up Its Secrets

January 16, 2020 by Jenny List 17 Comments

Providing a display for a project in 2020 is something of a done deal. Standard interfaces and off-the-shelf libraries for easily available and cheap modules mean that the hardest choice you’ll have to make about a display will probably relate to its colour. Three decades ago though this was not such a straightforward matter though, and having a display that was in any way complex would in varying proportion take a significant proportion of your processing time , and cost a fortune. [AnubisTTP] has an unusual display from that era, a four-digit LED dot matrix module, and the take of its reverse engineering makes for a fascinating read.

The LITEF 104267 was made in 1986, and is a hybrid circuit in a metal can with four clear windows , one positioned over each LED matrix. Inside are seven un-encapsulated chips alongside the LED matrices on a golf plated hybrid substrate. The chips themselves are not of a particularly high-density process, so some high-resolution photography was able to provide a good guess at their purpose. A set of shift registers drive the columns through buffers, while the rows are brought out to a set of parallel lines. Thus each column can be illuminated sequentially with data presented on the rows. It’s something that would have saved a designer of the day a few extra 74-series chips, though we are guessing at some significant cost.

This display may seem antiquated to us today, but it wasn’t the only option for 1980s designers. There’s one display driver from back then that’s very much still with us today.

A Replica From WarGames, But Not The One You Think

January 14, 2020 by Tom Nardi 23 Comments

Remember the WOPR from WarGames? The fictional supercomputer that went toe-to-toe with Matthew Broderick and his acoustic coupler was like a love letter to the blinkenlight mainframes of yesteryear, and every hacker of a certain age has secretly yearned for their own scaled down model of it. Well…that’s not what this project is.

The [Unexpected Maker] is as much a WarGames fan as any of us, but he was more interested in recreating the red alphanumeric displays that ticked along as the WOPR was trying to brute force missile launch codes. These displays, complete with their thoroughly 1980s “computer” sound effects, were used to ratchet up the tension by showing how close the supercomputer was to kicking off World War III.

Of course, most us don’t have a missile silo to install his recreated display in. So when it’s not running through one of the randomized launch code decoding sequences, the display doubles as an NTP synchronized clock. With the retro fourteen segment LEDs glowing behind the smoked acrylic front panel, we think the clock itself is pretty slick even without the movie references.

Beyond the aforementioned LEDs, [Unexpected Maker] is using a ESP32 development board of his own design called the TinyPICO. An associated audio “Shield” with an integrated buzzer provides the appropriate bleeps and bloops as the display goes through the motions. Everything is held inside of an understated 3D printed enclosure that would look great on the wall or a desk.

Once you’ve got your launch code busting LED clock going in the corner, and your illuimated DEFCON display mounted on the wall, you’ll be well on the way to completing the WarGames playset we’ve been dreaming of since 1983. The only way to lose is to not play the game! (Or something like that…)

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A Simple POV Globe Via APA102

January 10, 2020 by Lewin Day 30 Comments

POV builds come in all shapes and sizes, and typically rely on LEDs for their high light output and fast response time. With this in mind, [Great Scott] grabbed some LED strip off the shelf and set about whipping up a POV LED globe.

Being a spinning POV build, it’s necessary to consider how to get power to the rotating elements. [Great Scott] decided to go with a simple solution of putting a LiPo battery on the rotating assembly, which runs the LEDs and Arduino Nano at the heart of the operation. The LEDs in question are of the APA102 type, making them readily addressable and capable of a wide color gamut. It’s all spun by a simple brushed DC motor, running from a separate supply at the base of the platform.

It’s very much a hacker build, held together with duct tape and zipties. Despite this, it looks tidy when in operation, as all of the important hardware is hidden at the centre of the globe. There’s a bit of a vibration problem, but [Great Scott] reckons this can be fixed with some frame modifications.

We’d love to see the build run some more advanced operations, like a representation of the Earth, or some kind of sun clock. If you’re interested in learning more about POV displays, we’ve got the primer you need. Video after the break.

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Diurnal Reef Control Realistically Insolates Your Aquarium

January 3, 2020 by Gerrit Coetzee 14 Comments

[Phillip]’s project is not just great for learning new words, it also shows just how complex natural systems can be.

As we know from news around the word, reefs are delicate systems prone to damage from just about any imaginable threat. Escaped aquarium fish, sunscreen, and the wayward feet of well meaning tourists to name a few. So it’s no wonder that aquarium hobbyists sometimes go to incredible lengths to simulate the natural environments these creatures live in.

While [Phillip] is still tinkering with his designs for this project, we found the data he included really interesting. His goal is to be able to plug in any coordinate on the earth and have the lights replicate the location. That includes not just the sun, but also the light from the moon as many corals seem to only spawn during certain tides. Of course no LED is perfect so he’s even experimenting with putting light sensors under the water to provide a feedback loop to make it perfect.

We really like the ambition of this project and we hope he continues.

PoE Powers Christmas Lights, But Opens Up So Much More

December 31, 2019 by Jenny List 12 Comments

Addressable LEDs are a staple of homemade Christmas decorations in our community, as is microprocessor control of those LEDs. So at first sight [Glen Akins]’ LED decorated Christmas tree looks pretty enough, but isn’t particularly unusual. But after reading his write-up you’ll discover there’s far more to the project than meets the eye, and learn a lot about the technologies behind it that has relevance far beyond a festive light show.

The decoration is powered exclusively from power-over-Ethernet, with a PIC microcontroller translating Art-Net DMX-over-Ethernet packets into commands for the LED string. The control board is designed from the ground up and includes all the PoE circuitry, and the write-up gives a very thorough introduction to this power source that takes the reader way beyond regarding PoE as simply another off-the-shelf black box. Along the way we see all his code, as well as learn a few interesting tidbits such as the use of a pre-programmed EEPROM containing a unique MAC address.

So if your house has CAT5 wiring and you want an extra dimension to your festive splendour, you’ve officially got a whole year to build your own version. He’s featured here before, with his buzzer to break the Caps Lock habit.

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