Author: Tyler August

277 Articles

Determine Fundamental Constants With LEDs And A Multimeter

May 17, 2025 by 14 Comments

There are (probably) less than two dozen fundemental constants that define the physics of our universe. Determining the value of them might seem like the sort of thing for large, well funded University labs, but many can be determined to reasonable accuracy on the benchtop, as [Marb’s Lab] proves with this experiment to find the value of Planck’s Constant.

[Marv’s Lab] setup is on a nice PCB that uses a rotary switch to select between 5 LEDs of different wavelengths, with banana plugs for the multi-meter so he can perform a linear regression on the relation between energy and frequency to find the constant. He’s also thoughtfully put connectors in place for current measurement, so the volt-current relationship of the LEDs can be characterized in a second experiment. Overall, this is a piece of kit that would not be out of place in any high school or undergraduate physics lab. Continue reading “Determine Fundamental Constants With LEDs And A Multimeter” →

This Extra-Large, Two-Stage Fume Extractor Really Sucks

May 17, 2025 by 10 Comments

Solder fumes are not nice on the lungs; nor are fumes from superglue, epoxy, or a whole mess of other things we often find ourselves using on the bench. Some people might be able to go the fume hood route to toss that all outside, but for the rest of us, there’s fume extractors. [Raph] has produced an extra-large, carbon-filtering, two-stage fume extractor that by all accounts really sucks — it is effective at hoovering up solder fumes up to 10″ from its inlet.

Photo of fume extractor
Note the 18V tool battery in the base. That’ll go for a bit.

Even better, [Raph] built a battery box for an 18 V cordless tool battery, and broke out banana plugs so this doubles as a variable power supply via a cheap LM2596 based DC-DC converter. It also serves as a speed controller for the fans, which makes us wonder if you can adjust the PSU output and the fan speed independently…

Maximum suckage is achieved through careful baffle design. Check out the blog to see the trial-and-error process at work. Of course, having a 200 mm axial fan and 140 mm blower fan front and rear is going to move some air no matter what. Which is required to get air flow through the 38 mm thick activated carbon filter that should scrub all nasties quite nicely. We aren’t filtration experts but we can agree with [Raph]’s estimate that it will last “a while”.

If you want to roll your own, all of the STEP files are on GitHub, and [Raph]’s blog has an excellent step-by-step build guide. We’ve seen other hacks from [Raph] before, from his dovetailed modular breadboard to the machine that shaped his bed and automation for his camper van.

Hack Aims For Polaroid, Hits Game Boy Camera Sweet Spot

May 16, 2025 by 9 Comments

There’s just some joy in an instant camera. They were never quality cameras, even in the glory days of Polaroid, but somehow the format has survived while the likes of Kodachrome have faded away. [Mellow_Labs] decided he wanted the instacam experience without the Polaroid pricing, so he made his own in the video embedded after the break.

He says “Polaroid’ but we see Game Boy.

At its core, it’s a simple project: an ESP32-CAM for the image (these were never great cameras, remember, so ESP32 is fine– and do you really get to call it an instant camera if you have to wait for a Raspberry Pi to boot up?) and a serial thermal printer for the “instant photo”part. This admittedly limits the project to black and white, and pretty low res, but B/W is artistic and Lo-Fi is hip, so this probably gives the [Mellow Labs] camera street cred with the kids, somehow. Honestly, this reminds us more of the old Gameboy Camera and its printer than anything made by Polaroid, and we are here for it.

The build video goes through the challenges [Mellow Labs] found interfacing the serial printer to the ESP32–which went surprisingly well for what looks like mostly vibe coding, though we’re not sure how much time he spent fixing the vibe code off camera–as well as a the adventure of providing a case that includes the most absurdly beefy battery we’ve ever seen on a camera. Check out the full video below.

Instant cameras are no stranger to Hackaday: this one used e-ink; this one uses film, but is made of gingerbread. In 2022 we wondered if we’d ever shake the Polaroid picture, and the answer appears to be “no” so far.

Thanks to [Mellow] for tooting his own horn by submitting this project to the tip line. We love to see what our readers get up to, so please– toot away!

Continue reading “Hack Aims For Polaroid, Hits Game Boy Camera Sweet Spot” →

LED Layer Makes Plywood Glow

May 14, 2025 by 4 Comments

Plywood is an interesting material: made up of many layers of thin wood plys, it can be built up into elegantly curved shapes. Do you need to limit it to just wood, though? [Zach of All Trades] has proved you do not, when he embedded a light guide, LEDs, microcontrollers and touch sensors into a quarter inch (about six millimeter) plywood layup in the video embedded below.

He’s using custom flexible PCBs, each hosting upto 3 LEDs and the low-cost PY32 microcontroller. The PY32 drives the RGB LEDs and handles capacitive touch sensing within the layup. In the video, he goes through his failed prototypes and what he learned: use epoxy, not wood glue, and while clear PET might be nice and bendy, acrylic is going to hold together better and cuts easier with a CO2 laser. Continue reading “LED Layer Makes Plywood Glow” →

2025 Pet Hacks Contest: Automatic Treat Dispenser Makes Kitty Work For It

May 14, 2025 by 10 Comments

Treat dispensers are old hat around here, but what if kitty doesn’t need the extra calories — and actually needs to drop some pounds? [MethodicalMaker] decided to link the treat dispenser to a cat wheel, and reward kitty for healthy behaviors. The dispenser can be programmed to make the cat run long enough to burn the calories of its treat. Over time, kitty can be trained to run longer between treats to really melt off the pounds.

The wheel itself is an off the shelf model called “One Fast Cat”; apparently these are quite cheap second hand as most cats don’t really see the point in exercise. [MethodicalMaker] glued evenly-spaced magnets along the rim in order to track the rotation with a hall effect sensor.  A microcontroller is watching said sensor, and is programmed to release the treats after counting off a set number of revolutions. Control over the running distance and manual treat extrusion is via web portal, but the networking code had difficulty on the Arduino R4 [MethodicalMaker] started with, so he switched to an ESP32 to get it working.

The real interesting part of this project is the physical design of the treat dispenser: it uses a double-auger setup to precisely control treat release. The first auger lives inside a hopper that holds a great many treats, but it tended to over-dispense so [MethodicalMaker] methodically made a second auger that sits beneath the hopper. The handful of treats extruded by the first auger are dispensed individually by the second auger, aided by a photosensor inside the exit chute to count treats. This also lets the machine signal when it needs refilling. For precise control, continuous servos are used to drive the augers. Aside from the electronics, everything is 3D printed; the STLs are on Printables, and the code is on GitHub.

If you don’t have a cat wheel, DIY is an option. If you don’t have a cat, we’ve also highlighted dog treat dispensers. If you don’t have either, check with your local animal shelter; we bet good money there are oodles ready to adopt in your town, and then you’ll have an excuse to enter one of your projects into our ongoing Pet Hacks Contest.

Continue reading “2025 Pet Hacks Contest: Automatic Treat Dispenser Makes Kitty Work For It” →

A Brain Transplant For A Philips Smart Lamp

May 14, 2025 by 25 Comments

As the saying goes, modern problems require modern solutions. When the modern problem is that your smart light is being hijacked by the neighbors, [Wejn]’s modern solution is to reverse engineer and replace the mainboard.

The light in question is a Phillips Hue Ambiance, and [Wejn]’s excellently-documented six part series takes us through the process of creating a replacement light driver. It’s a good read, including reverse-engineering the PWM functions to get the lights to dim exactly like stock, and a dive into the Zigbee protocol so his rebuild light could still talk to the Philips Hue hub. The firmware [Wejn] wrote for the ESP32C6 he chose to use for this project is on GitHub, with the PCB in a second repo.

We want to applaud [Wejn] for his excellent documentation and open-sourcing (the firmware and PCB are under GPL v3). Not only do we get enough information to replicate this project perfectly if we so choose, but by writing out his design process, [Wejn] gives everyone reading a good head start in doing something similar with other hardware. Even if you’re scratching your head wondering why a light switch isn’t good enough anjymore, you have to appreciate what [Wejn] is offering the community.

We’ve covered domestic brain transplants in the past — which is easier in this sort of light than the close confines of a smart bulb. If you’re still wondering why not just use a light switch, perhaps you’d rather hack the light to run doom instead.

Before you go, can we just take a moment to appreciate how bizarre the world has become that we have a DOOM-capable computer to run fancy light fixture? If you’re using what might have been a decent workstation in days of yore to perform a painfully mundane task, let us know on the tips line.

Print PLA In PLA With A Giant Molecular Model Kit

May 12, 2025 by 1 Comment

It isn’t too often we post a hack that’s just a pure 3D print with no other components, but for this Giant Molecular Model kit by [3D Printy], we’ll make an exception. After all, even if you print with PLA every day, how often do you get to play with its molecular bonds? (If you want to see that molecule, check out the video after the break.)

There are multiple sizes of bonds to represent bond lengths, and two styles: flexible and firm. Flexible bonds are great for multiple covalent bonds, like carbon-carbon bonds in organic molecules. The bonds clip to caps that screw in to the atoms; alternately a bond-cap can screw the atoms together directly. A plethora of atoms is available, in valence values from one to four. The two-bond atom has 180 and 120-degree variations for greater accuracy.  In terms of the chemistry this kit could represent, you’re only limited by your imagination and how long you are willing to spend printing atoms and bonds.

[3D Printy] was kind enough to release the whole lot as CC0 Public Domain, so we might be seeing these at craft fairs, as there’s nothing to keep you from selling the prints. Honestly, we can only hope; from an educational standpoint, this is a much better use of plastic than endless flexy dragons.

If you’d prefer your chemistry toys help you do chemistry, try this fidget spinner centrifuge. Perhaps you’d rather be teaching electronics instead?

Continue reading “Print PLA In PLA With A Giant Molecular Model Kit” →