An IR Blaster Project, In A Nutshell

September 28, 2026 by Bryan Cockfield 30 Comments

The speed that computers have gotten smaller is a bit mind-bending. Most of us now walk around with computers in our pockets that would have rivaled the supercomputers from a few decades ago. And, although it seems like the speed at which things are getting smaller and faster has slowed a bit compared to the rapid pace of the 90s and 00s, some truly minuscule computers are accessible nowadays. So much so that it’s possible to do useful computing inside a walnut shell.

The first step in this build is to crack into a walnut. Most have a natural seam that separates two hemispheres, so splitting it open, enjoying a small snack, and then adding some small neodymium magnets on the inside of that seam to close up the shell is not too difficult. From there, some LEDs were installed at various points in the shell, with an ESP32-C3 installed in the middle to control everything and oriented so that its USB port is still accessible.

Although putting a small microcontroller in a nutshell might seem like a novelty, [JSK-koubou] is actually using the LEDs to perform a useful task. The walnut sits in his living room and connects to a home automation system through the ESP32, and when it receives a command it uses the LEDs to send infrared signals to non-connected devices. Hiding projects in unexpected places is a fun pastime, like this Meshtastic node hidden in a landscape light.

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Eye-D Badge Catches Your Attention

September 17, 2026 by Zoe Skyforest 5 Comments

Head out to your next corporate conference, and you’ll probably be handed a little paper badge in a plastic holder so people can learn what to call you (or whether they should talk to you at all). It serves a function, but it’s a little soulless. [Aahan Sharma]’s Eye-D badge is a touch more interesting.

At the heart of the build is an ESP32-C6 microcontroller. It’s a capable part, with clock speed configurable up to 160 MHz, and wireless connectivity baked in. It’s hooked up to an 8 x 16 matrix of WS2812B addressable RGB LEDs, creating a color 128-pixel display. [Aahan] took advantage of the onboard Bluetooth Low Energy connection of the ESP32 to enable the display to be readily controlled by a smartphone, tablet, or laptop.

It can be configured to display a name, social handle, or custom message as desired. Beyond that, it can display animations, like an eye scanning around the room, Nyan Cat, or fire or Matrix-like effects just for the fun of it. There’s also a Draw Mode that lets one create their own pixel art on the display, too. [Aahan] wanted the build to feel like a serious conference badge, rather than a random electronic trinket, so whipped up a custom enclosure. The LEDs, microcontroller, and a battery, are all wrapped up in a tidy 3D printed housing with a ring for easily hanging the badge from clothes, lanyard, bag, or similar.

If you’re running your own little conference and have the budget for something cool, you might like to build a run of these. Or, you could explore some of the more advanced badge designs that are out there.

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Building An Energy-Harvesting Business Card

August 31, 2026 by Zoe Skyforest 12 Comments

The hope is always that a good business card will leave a good impression. For those in the electronics field, they also serve as an opportunity to showcase creative design skills. [Wilson Harper] demonstrates that ably with a rather nifty energy-harvesting build.

The card is based around a thin PCB in the typical business card size. It’s populated by 21 Charlieplexed LEDs, a small microcontroller, and some supporting components. Now, this is normally where you might expect the device to be powered by a small coin cell, maybe deftly integrated into the PCB thickness itself to make the card less cumbersome. But no—[Wilson] went a different route. The thing is that in 2026, most of us are carrying phones with NFC readers built in. Thus, the card was built to harvest this source of energy with a PCB trace antenna, designed with the aid of STM’s antenna inductance tools and an LLM script lobbed into KiCad. All one needs to do is to pop the card on the back of a phone and the LEDs animate joyfully.

Design files are on Github for the curious. You might also like to check out some of the fancy business cards we’ve featured in the past. Of course, if you’re working on just such a project yourself, you’re more than welcome to send it in to the tipsline!

Architectural LED Install Shows How To Do It With Style

August 2, 2026 by Zoe Skyforest 6 Comments

Anyone can string up some LED string lights in a space with mixed results. However, if you want to create a lighting environment that’s classy and stylish, it takes a little more finesse. [ipad.bendavid] has a great example of this, with a rather tidy architectural LED installation.

The final look is quite clean and evenly lit, without requiring the use of any diffuser material.

The electronic side of things is relatively straightforward. There’s an ESP32 running the show, commanding the colors for 928 individually-addressable WS2812 RGB LEDs. It uses the WebSocket API for real time control, integrates with Home Assistant, and even offers audio reactive lighting modes with the aid of an INMP441 I2S audio input module. A hefty 5 V, 60 A power supply ensures the LEDs are never short of juice. There was also careful attention paid to power distribution to avoid any dim spots or other issues.

Where it gets really cool, though, is the attention paid to the construction of the installation. The LED strips are installed in concentric square frames, which block light in specific areas to create a nice square pattern, with the LEDs facing the wall they’re installed on rather than projecting out to the viewer. This hides the strips themselves and eliminated the need for diffusers which can be a pain to get right.

Overall, the build is a pleasing one that plays with light and darkness and looks rather stylish in a way so many LED installs don’t. If you’re cooking up your own neat glowable projects, you know we’d love to see them on the tipsline.

A Complex Way To Push A Button

July 31, 2026 by Bryan Cockfield 17 Comments

We’ve likely all looked at a simple problem in our lives and thought that it would be an easy fix, only to realize that the project is enormously more complicated than we first realized. Whether that’s starting a home improvement project, doing a quick repair to a bicycle or car, or trying to install an obscure piece of software on a Linux machine, the amount of time we budget for these tasks often ends up woefully underestimated. [Oscar]’s night light needs to have its brightness set every night, and it seems easy enough to get a microcontroller to automate that, right?

Well, upon opening the small device, the first issue is that there is no labeling on any of the parts, so simply adding a jumper on to existing microcontroller pins without damaging anything wouldn’t easily be possible. Adding a secondary microcontroller is the next logical step, but the power supply in the night light is extremely underpowered so using even the smallest Raspberry Pi or off-the-shelf Arduino was out of the question too. [Oscar] instead chose an ATtiny85, which solves the power requirement issue, but these are a bit more of a challenge to program without a USB device. From there, it needs a transistor wired in to the circuit to actually push the button for him, plus a few support resistors, so [Oscar] actually had a PCB custom-built to hold all of these components.

Even after all of that, the space within the night light enclosure made installing the PCB a challenge, but in the end he has a device which, when his home automation system powers on the plug for the nightlight, automatically boots up and pushes the switch the required number of times and then puts itself to sleep. We’d call that a success even after the colossal effort getting this inexpensive, small light working the way he wanted. There are some other low-powered solutions for problems like these too, as long as being battery-powered isn’t a dealbreaker.

A Light-Up Map Of Monaco

July 2, 2026 by Zoe Skyforest 4 Comments

If you want to get around Monaco, a map — digital or otherwise — is probably the best way to navigate. But if you just want to appreciate the city’s form in a more artistic way, you might enjoy [Terence Grover’s] latest project—a backlit topographic map of the unique principality.

The touch mode allows one to draw patterns across the map.

The project started with a QGIS mesh of Monaco, with the data fed through the Open-Meteo elevation API, which takes into account building heights. This was used as the basis for the heights of 179 pieces of 20 mm x 20 mm acrylic. These were assembled into a laser cut steel base, and were sanded on all sides but the base in order to allow them to diffuse light more effectively.

Strips of CS8812 LEDs are used to light the plastic towers, driven by a pair of Adafruit Feather RP2040 Scorpio boards. They’re fed pixel data from a Raspberry Pi 5, which runs a Flask panel accessed over an iPad. This allows control over the LED map display, showing things like civic data, highlighted events, and weather. There’s even a touch-sensitive mode that lets one paint fun patterns across the representation of the city.

We love a good artistic map, particularly when they’re full of LEDs and represent useful information.

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An RGB Keyboard For Your Hackaday Communicator Badge

June 4, 2026 by Jenny List 1 Comment

The most recent Hackaday event badge has been the Communicator, a handheld wireless terminal with a rather nice QWERTY keyboard. It’s good enough as delivered, but [makeTVee] has gone one better and made his Communicator keyboard into a fully RGB light-up experience.

The feat is achieved with the help of a new front panel holding some very thin side-emitting addressable LEDs. The keys are custom-printed, and there’s a TPU mat to hold them all together. The LEDs are driven from one of the device’s GPIOs.

We saw this badge in real life at the recent Hackaday Europe conference in Lecco, Italy. It really is as good as it looks in the video below, the care and attention which has gone into the build is extremely impressive.The original badge used a silicone cast set of keys, and we’d say if you are making a device with a keyboard then these might make a very good option.

If you’re not familiar with the Communicator, it’s worth having a look at the launch announcement.

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