Reverse Engineering Saves Trashed LED Panels

May 9, 2020 by Tom Nardi 8 Comments

While out riding his bike, [Hammond Pearce] came across a dumpster overflowing with large LED panels. Despite the fact that the model numbers didn’t reveal anything helpful after some online searching, he decided to pedal off with as many as he could safely carry. The COVID-19 lockdown left him with only a limited set of tools, be he still managed to crack the protocol used to control his e-waste score and document it for our reading pleasure.

Between the helpful labels on the PCB silkscreen and the advice of a friend that used to work on digital road signs, it didn’t take [Hammond] long to get a general idea of what the panels were looking for in terms of power and control. Especially once he noticed the MBI5024 shift registers dotting the board.

The next step was to take an ATmega328PB based development board and start throwing data at the panel’s input lines to see if he could elicit a response. With careful attention and some custom code, he eventually figured out that each byte of data sent down the line would control a 4 x 2 section of LEDs.

Once he had the basics down, the next step was to start expanding his code to handle things like shapes, text, and daisy-chained panels. After posting some of his work to Reddit, cyber-sleuths determined that the protocol appeared to be some variation of HUB75, which gave [Hammond] hints on what some of the other pins in the connector might be used for. He’s released all of his code online for anyone who might find it useful, but since he still doesn’t know who made these panels and why there’s really no telling how many of them are actually floating around out there.

Figuring out how to talk to an unknown or undocumented piece of hardware can be intimidating, but success stories like these are reminders of why it’s worth putting the effort in. As we’ve seen, the difference between trash and treasure is often a keen eye and a few lines of code.

These LED Shades Will Blind You With Science

May 8, 2020 by Tom Nardi 9 Comments

Unless you’re particularly fond of looking at the back of 88 individual WS2812B LEDs, these “RGB Goggles” from [Mukesh Sankhla] won’t offer you much of a view. But from an outsider’s perspective, the smartphone-controlled glasses certainly make a statement. Just don’t try to operate any heavy machinery while wearing them.

The build starts off with a pair of shades dark enough that the lights won’t be obvious until they’re powered up. [Mukesh] then carefully aligned the LEDs into a grid pattern on a piece of clear tape so they could be soldered together with the fewest number of jumper wires possible. Even if you’re not in the market for some technicolor eyewear, this clever arrangement of WS2812B modules could come in handy if you’re looking to make impromptu LED panels.

To control the LEDs, [Mukesh] is using an Arduino Nano and an HC-06 Bluetooth module that’s linked to an application running on an Android smartphone. The software, developed with the MIT App Inventor, allows the user to easily switch between various patterns and animations on the fly. With such an easy-to-use interface, the RGB Goggles don’t look far off from a commercial product; other than the whole not being able to actually see through the thing.

We’ve actually seen a number of custom glasses projects over the years, as it seems that a cheap pair of shades make an ideal platform for head-mounted hacks. We’ve even found what may be the ideal power source for them.

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Break Time Is Calling On The Rainbow Connection

May 4, 2020 by Kristina Panos 6 Comments

Like some of us, [Mister M] is prone to staying glued to his seat too long in this new era of working from home. And you know what they say about a body at desk — it tends to stay at desk until it absolutely must rise up to find food or use the restroom.

Thanks to this nifty new break time reminder, [Mister M] has a third call to answer that demands he get up. Every hour, the NeoPixel ring in this old dial-deficient phone fills up completely and switches over to an attention-getting rainbow animation. If [Mister M] stays seated, playtime is over. All the lights start flashing red, and the phone starts beeping incessantly until he walks across the room and either pushes the momentary button or lifts the handset to reset the timer.

We love that [Mister M] incorporated all of the phone’s original inputs and outputs into this project, because it’s such a cool old dog and bone. No need to drop a dime, just whistle at the break button to check out the build video.

This grille-faced phone was probably part of an intercom system. Incidentally, you can make an intercom system with two standard-style phones of this vintage.

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Go The Extra Mile For Your LED Driver

May 4, 2020 by Kerry Scharfglass 7 Comments

Addressable RGB LED strips may be all the rage, but that addressability can come at a cost. If instead of colors you expect to show shades of white you may the find less flickery, wider spectrum light from a string of single color LEDs and a nice supply desirable. Of course there are many ways to drive such a strip but this is Hackaday, not Aliexpressaday (though we may partake in the sweet nectar of e-commerce). [Niklas Fauth] must have really had an itch to scratch, because to get the smoothest fades for his single color LED strips, he built an entire software defined dual 50W switched-mode AC power supply from scratch. He calls it his “first advanced AC design” and we are suitably impressed.

Switched-mode power supplies are an extremely common way of converting arbitrary incoming AC or DC voltage into a DC source. A typical project might use a fully integrated solution in the form of a drop-in module or wall wart, or a slightly less integrated controller IC and passives. But [Niklas] went all the way and designed his from scratch. Providing control he has the ubiquitous ESP-32 to drive the control nodes of the supply and giving the added bonus of wireless connectivity (one’s blinkenlights must always be orchestrated). We can’t help but notice the PCBA also exposes RS485 and CAN transceivers which seem to be unused so far, perhaps for a future expansion into wired control?

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Viewing Countrywide Weather At A Glance

May 3, 2020 by Tom Nardi 5 Comments

For his latest project, weather display aficionado [Richard] has put together a handsome little device that shows the temperatures recorded at nine different airports located all over the British Isles. Of course the concept could be adapted to wherever it is that you call home, assuming there are enough Internet-connected weather stations in the area to fill out the map.

The electronics are fairly minimal, consisting of a NodeMCU ESP8266 development board, a few seven segment LED display modules, and a simple power supply knocked together on a scrap of perfboard. As you might expect, the code is rather straightforward as well. It just needs to pull down the temperatures from an online API and light up the displays. What makes this project special is the presentation.

As [Richard] shows in the video after the break, the key is a sheet of acrylic that’s been sanded so it diffuses the light of 42 LEDs that have been painstakingly installed in holes drilled around the edge of the sheet. Combined with a printed overlay sheet, this illuminates the map and its legend in low-light conditions. It’s a simple technique that not only looks fantastic, but makes the display easy to read day or night. Definitely a tip worth mentally filing away, as it has plenty of possible applications outside of this particular build.

With his projects, [Richard] has shown himself to be a master of unique and data-rich weather displays, and a great lover of the iconic seven segment LED display. While his particular brand of climate data overload might not be for everyone, you’ve got to admire his knack for visualizing data.

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Millennium Falcon Docking Bay Doubles As Table

April 22, 2020 by Tom Nardi 13 Comments

A glass table makes a perfect display case for showing off whatever’s important to you, but if you want keep the dust off of your treasures, closing up the sides is probably a wise move. It might not be a bad idea to put some lighting in there to make sure everything is easy to see. You might as well make the lights RGB and remote controlled, so you can fiddle with the look from across the room. Of course, you could go all in and just make the thing a diorama…

It’s not hard to imagine the line of thinking that convinced [Erv Plecter] he should turn a simple glass table into a docking bay for a model of the Millennium Falcon, and looking at the final results, we think it was the right move. With an incredible attention to detail, what started out a generic looking table and rather modest toy, have been combined into an interactive display that could woo even the staunchest of Trekkies.

If you’ve ever considered lighting a model, this project is an excellent example to follow. The Hasbro toy that [Erv] started with certainly wasn’t what you’d call studio quality; the little lighting it featured wasn’t even accurate to how the ship appears in the films. But with some reference material, fiber optic cables, and enough Arduinos to drive it all, the final lighting is truly a marvel. We’d say the engine is our favorite part, but those tiny lit panels in the cockpit are hard to beat.

While the Falcon is clearly the star of the show, the docking bay itself is certainly no afterthought. The back-lit panels, with their inscrutable Imperial design aesthetic, look fantastic. The addition of small details like crates and barrels, plus the glossy black PVC sheet used for the floor, really brings the whole scene to life. It’s almost a shame that the ship itself is so big, as a smaller model would have left more room to toss in a few Stormtroopers and droids out on patrol.

This isn’t the first time we’ve seen somebody augment a “toy” grade model with additional lighting effects. While the scale miniature aficionados in the audience might turn their nose up at some of the artistic liberties taken on these low fidelity models, we think any normal person would be blown away if they saw them in person.

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RGB Kitchen Uses Pots To Stir Up Color

April 17, 2020 by Kristina Panos 3 Comments

Anyone who has done anything with RGB LEDs knows that their ability to display pretty much any color is somehow both the best and worst thing about them. How do you get it right? How do you make your results repeatable? [Thomas] has the answer. He dug around in the ol’ parts cupboard, found a few pots, and got to work making this stay-home stew of a project — an on-demand RGB LED color mixer.

Three cleverly color-coded potentiometers and an Arduino let [Thomas] step through 0-255 to mix various values of red, blue, and green. The shade that gets made is displayed live on a set of 10 individual NeoPixels that are laid out under a frosty diffusing panel. Each of the RGB values are also shown on an 16×2 LCD.

This is one of those projects that hits a sweet spot of being simple, useful, and fun. It’s even nice-looking and compact. What more could you want from a project cobbled together from ingredients on hand? [Thomas] is even giving away the code recipe.

Once you dial in your ideal colors, why not make a gesture-controlled lamp?