Minimalist LED Lamp Is Circular Beauty Incarnate

September 4, 2023 by Lewin Day 8 Comments

Lamps used to be things built to provide light with specific purpose, whether as reading lamps, desk lamps, or bedside table lamps. Now we just build them for the vibes, as with this minimalist LED lamp from [andrei.erdei].

The build uses a 3D-printed frame printed in opaque grey, with a diffuser element printed in a more translucent white. This is key to allowing the LED to nicely glow through the lamp without ugly distracting hotspots spoiling the effect. The lamp mounts 36 WS2812B LEDs in strip form. These are controlled from an Arduino Nano running the FastLED library for lightweight and easy control of the addressable LEDs. Smooth rainbow animations are made easy by the use of the HSV color space, which is more suitable for this job than the RGB color space you may otherwise be more familiar with.

[andrei.erdei] does a great job of explaining the build, including the assembly, electronics, and code aspects. The latter could serve as a particularly good resource if you’re just starting out on your own builds in the blinky, glowable space. Video after the break.

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Why Are We Only Just Now Hearing About LED Beaded Curtains

August 31, 2023 by Lewin Day 20 Comments

Beaded curtains are a pretty banal piece of home decor, unlikely to excite most interior design enthusiasts. Throw on some addressable LEDs, though, and you’ve got something eye-catching at the very least, as [Becky] demonstrates.

Joining the LED strands at the bottom made running the wiring easy but made walking through the blinds hard.

The project started with an existing beaded curtain as a base. A series of addressable LED strands were then carefully sewn to the beads using knots tied in plain sewing thread. The strands were configured as a single strand as far as the data lines were concerned, to make animation easy. Power was supplied to both ends of the strand to ensure nice and even brightness across the strands.

The brains of the system is a PixelBlaze controller, which makes it easy to wirelessly control the behavior of the strings. It’s the perfect tool for quickly whipping up fancy animations and pretty effects without hand-assembling a bunch of code yourself.

There was only a few problems with the project. [Becky] found a pretty passable LED beaded curtain from China midway through the project, which reduced her enthusiasm to finish the build. There were also issues walking through the curtain due to the wiring scheme she chose, where the bottom of one strand was connected to its neighbor.

Regardless, it’s a fun blinky build that brings some color to an otherwise drab doorway. It’s hard to complain about that! Video after the break.

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Wireless Data Connections Through Light

August 25, 2023 by Bryan Cockfield 38 Comments

When wired networking or data connections can’t be made, for reasons of distance or practicality, various wireless protocols are available to us. Wi-Fi is among the most common, at least as far as networking personal computers is concerned, but other methods such as LoRa or Zigbee are available when data rates are low and distances great. All of these methods share one thing in common, though: their use of radio waves to send data. Using other parts of the electromagnetic spectrum is not out of the question, though, and [mircemk] demonstrates using light as the medium instead of radio.

Although this isn’t a new technology (“Li-Fi” was first introduced in 2011) it’s not one that we see often. It does have a few benefits though, including high rates of data transmission. In this system, [mircemk] is using an LED to send the information and a solar cell as the receiver. The LED is connected to a simple analog modulator circuit, which takes an audio signal as its input and sends the data to the light. The solar cell sends its data, with the help of a capacitor, straight to the aux input on a radio which is used to convert the signal back to audio.

Some of the other perks of a system like this are seen here as well. The audio is clear even as the light source and solar cell are separated at a fairly significant distance, perhaps ten meters or so. This might not seem like a lot compared to Wi-Fi, but another perk shown is that this method can be used within existing lighting systems since the modulation is not detectable by the human eye. Outside of a home or office setting, systems like these can also be used to send data much greater distances as well, as long as the LED is replaced with a laser.

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Hackaday Prize 2023: Jumperless, The Jumperless Jumperboard

August 25, 2023 by Dave Rowntree 9 Comments

Jumperless is a jumperless breadboard with multicolored LED visualization of signals in real-time. Sounds like magic? This beautifully executed entry to the 2023 Hackaday Prize by [Kevin Santo Cappuccio] uses a boatload of CH446Q analog switch ICs to perform the interconnect between the Raspberry Pi Pico header and the jumper board (or breadboard if you prefer.)

This will add some significant resistance, but for low currents and digital logic levels, this should not be a major concern. Additionally, there are two DAC channels and four ADC channels to help break out of the digital world, which could make for some very interesting non-trivial applications.

The visualization of the Pico header signals is solved neatly with a tiny wishbone-shaped PCB that is reverse-mounted to the back of the main board to illuminate upwards. The masking of the labels is done by using copper to mask off the individual signals and solder mask to draw in the legends. This PCB-level hacking is simply wonderful to see. The PCBs are designed with KiCAD, the design files for which you can find here. It appears however that [Kevin] needed to have the spring clips for the jumper board custom-made, so you’d need to contact them if you needed to get some for a build.

On the software side of things, [Kevin] currently recommends using Wokwi, to run the Arduino stack applications and to perform the signal routing to the virtual jumper board. You can follow how it works internally here. A Python-based bridge application runs on the host computer, which takes care of programming the interconnects as they are constructed, which looking at the demo in the embedded video, appears to ‘just work.’

One word of caution though — the bridge app uses Python requests and Beautiful Soup to scrape the Wowki project page, which could potentially make it vulnerable to getting out-of-sync with updates, so hopefully [Kevin] will keep track of this and keep them in sync.

Need some breadboarding tips? We got you covered. Talking of bread, here’s an 8-bit TTL breadboard-based CPU in a breadbin.

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Hackaday Prize 2023: Ubo Project: Building For Builders

August 24, 2023 by Dave Rowntree 6 Comments

The Ubo Pod by [Mehrdad Majzoobi] is a very highly polished extension pack and enclosure for the Raspberry Pi 4, which shows you how far you can go to turn a bare PCB into something that rivals the hardware offerings from Google and others. Gadgets like the Sonos speakers and Amazon or Google’s covert listening devices (aka Echo, Alexa, or whatever they’re branded as) are fun to play with. Still, the difficulty of hacking custom applications into them and god-forbid adding one’s own extension hardware, makes them fairly closed ecosystems. Add in the concerns of privacy and data security; they look less and less attractive the closer you look. Luckily the Raspberry Pi and its friends have improved the accessibility to the point where it’s positively easy to create whatever you want with whatever hardware you need, and to that end we think [Mehrdad] has done a splendid job.

The custom top PCB sits below the wooden top surface, hosting a central LCD display with push buttons located around it. Also sitting atop are some IR transmitters and receivers as well as RGB LEDs for the ring lighting. This top PCB acts as a RPi hat, and plugs into an RPi4 below, which then attaches to a side board via some PCB-mounted connectors, matching up with the USB and audio connectors. This board seems to act purely as an interconnect and form-factor adaptor allowing interfaces to be presented more conveniently without needing wires. This makes for a very clean construction. Extensive use of resin printing is shown, with lots of nice details of how to solve problems such as LED diffusion and bleeding. Overall, a very slick and well-executed project, that is giving us a few ideas for our own projects.

This type of project is commonplace on these fair pages, like this DIY smart speaker for example. With the supply of pi being still a little difficult to deal with, could you roll your own or get an alternative? What about just using your old mobile phone?

Angry Robot Face Is Less Than Friendly

August 17, 2023 by Lewin Day 10 Comments

Sometimes you just need to create a creepy robot head and give it an intimidating personality. [Jens] has done just that, and ably so, with his latest eerie creation.

The robot face is introduced to us with a soundtrack befitting Stranger Things, or maybe Luke Million. The build was inspired by The Doorman, a creepy art piece with animatronic eyes. [Jens’] build started with a 3D model of a 3D mask, with the eyes and mouth modified to have rectangular cutouts for LED displays. The displays are run by a Raspberry Pi Pico, which generates a variety of eye and mouth animations. It uses a camera for face tracking, so the robot’s evil eyes seem to follow the viewer as they move around. In good form, the face has a simple switch—from good to evil, happy to angry. Or, as [Jens] designates the modes: “Fren” and “Not Fren.”

[Jens] does a great job explaining the build, and his acting at the end of the video is absolutely worth a chuckle. Given Halloween is around the corner, why not build five to eight of these, and hide them in your roommate’s bedroom?

Video after the break.
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PentaBlinky – When One LED Is Not Blinky Enough

August 10, 2023 by Dave Rowntree 4 Comments

[michimartini] over on Hackaday.io loves playing with multivibrator circuits, and has come across a simple example of a ring oscillator. This is a discrete transistor RC-delay design utilizing five identical stages, each of which has a transistor that deals with charging and discharging the timing capacitor, passing along the inverted signal to its nearest neighbor. The second transistor isn’t strictly needed and is only there to invert the signal in order to drive the LED. When the low pulse passes by the LED lights, without it you’d see all the LEDs lit bar one, which doesn’t look as good.

Compare this with an astable multivibrator to understand how it works

Essentially this circuit is just the classic astable multivibrator circuit that has been split in half and replicated so that the low pulse propagates through more stages than just the two, but thinking about it as a single stage doesn’t work so well until you draw in a couple of neighbors to help visualize the behavior better.

[michimartini] does lament that the circuit starts up in a chaotic fashion and needs a quick short applying to one transistor element in order to get it to settle into a steady rhythm. Actually, that initial behaviour could be interesting in itself, especially as the timing changes with voltage and temperature.

Anyway, we like the visual effect and the curvy organic traces. It would make a neat pin badge. Since we’re thinking about blinkies, here are couple of somewhat minimalist attempts, the world’s smallest blinky, and an even smaller one. Now, who doesn’t love this stuff?

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