A DIY coffee roaster with part callouts.

Follow The Red Ball Wobble Disk Roaster To Coffee Excellence

May 3, 2024 by Kristina Panos 6 Comments

If you’ve never considered roasting your own coffee at home, you may be surprised to learn that it can be done in a few minutes with a regular popcorn popper and not much else. After all, you only really need two things to roast coffee: heat, and constant agitation to distribute that heat evenly. While the popcorn popper provides both, it’s easy to end up with semi-uneven roasts, probably because the beans are mostly just spinning around and not being tossed as well as they could be. Eventually, one might want a more advanced machine, and that’s where something like [Larry Cotton]’s latest wobble disk roaster can step in.

For starters, this machine roasts more beans than the average popcorn popper in a single throw — the maximum is 350g, or just over three-quarters of a full pound, which is way more than the average popcorn machine will hold. It essentially consists of a heat gun pointed upwards at a sieve full of green coffee beans that are being constantly pushed around by a motorized wobbling disk. As the heat blows, the large metal disk does figure eights through the beans, keeping the heat nice and even. So where does the red ball come in? It’s at the bottom, keeping the flying bean skins (chaff) from entering the heat gun’s fan motor.

Toward the end of the short video after the break, you’ll see a diagram showing all the parts of this roaster. If that’s not enough for you, here’s a build guide for a previous wobble disk roaster (PDF) that should be quite helpful in building either version.

If you want to see some of Larry’s previous machines, we’ve got ’em. And then you can let Hackaday Editor-in-Chief [Elliot Williams] tell you all about roasting at home.

Continue reading “Follow The Red Ball Wobble Disk Roaster To Coffee Excellence” →

Hackaday Podcast Episode 269: 3D Printed Flexure Whegs, El Cheapo Bullet Time, And A DIY Cell Phone Sniffer

May 3, 2024 by Kristina Panos 1 Comment

This week, it was Kristina’s turn in the hot seat with Editor-in-Chief Elliot Williams. First up in the news — the results are in for the 2024 Home Sweet Home Automation contest! First and second place went to some really gnarly, well-documented hacks, and third went to the cutest pill-dispensing robot you’ll probably see before you hit the retirement home. Which was your favorite? Let us know in the comments.

A collection of multimeter probe extenders from Radio Shack. — Kristina’s lil’ wallet of extender probes, courtesy of Radio Shack.

Then it’s on to What’s That Sound. Kristina failed once again, but you will probably fare differently. Can you get it? Can you figure it out? Can you guess what’s making that sound? If you can, and your number comes up, you get a special Hackaday Podcast t-shirt.

Then it’s on to the hacks, beginning with a DIY cell phone sniffer and a pen that changed the world. Then we talk bullet time on a budget, the beautiful marriage of 3D printing and LEGO, and, oh yes, flexure whegs. Finally, we get the lowdown on extender probes, and posit why it’s hard to set up time zones on the Moon, relatively speaking.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Download and savor at your leisure.

Continue reading “Hackaday Podcast Episode 269: 3D Printed Flexure Whegs, El Cheapo Bullet Time, And A DIY Cell Phone Sniffer” →

A small gauge showing power generated by a house's solar panels.

Cute Solar Power Gauge Brightens The Day

May 2, 2024 by Kristina Panos 4 Comments

What’s the first thing you want after installing solar? All the sunshine you can get, of course. Especially if you did it in the wintertime. And what would be more fun than monitoring your power generation, especially leading up to the equinox, or start of spring? Probably not much, especially if you built a cute solar power gauge like [Ben] did to keep him from obsessively checking his phone.

At the heart of this build is the affordable Seeed Xiao ESP32C3, which controls an equally cost-effective automotive stepper via an L293D H-bridge driver. Then it was just a matter of hooking it into Home Assistant. As power is generated by the solar system, the cute little sun on the gauge rises and shows the kilowattage gained.

Unfortunately there’s no real data sheet for the stepper, so [Ben] opted to use the 5 V from the USB that’s powering the ESP32. However, it seems like this might not be enough power because the gauge appears to drift a bit. To fix this, [Ben] runs the stepper_init script twice a day, which cranks the dials all the way forward then all the way backward before settling on the last known value.

Are you interested in solar? Here’s how you can build a small power system.

A cyberdeck/portable PC sits on a deck rail in the sun.

T3rminal Cyberdeck Has Looks To Die For

May 1, 2024 by Kristina Panos 7 Comments

One of the greatest things about the hacker ecosystem is that whole standing-on-the-shoulders-of-giants thing. Somebody makes something and shares it, and then someone else takes that thing and remixes it, sometimes making it objectively better. For their T3rminal cyberdeck, [calebholloway08] was inspired by a number of projects and came up with something that looks simply fantastic.

Whether you want to call this beauty a cyberdeck or a mobile PC, the guts are what you might expect — a Raspberry Pi 4, an affordable mini keyboard, and a touch screen. But this one took some doing, as in [calebholloway08] had to do a little bit of surgery on the Pi 4, the PiSugar S plus power supply platform, and the display. But you shouldn’t let that stop you from standing on the shoulders of giants, as [calebholloway08] provides (or guides you towards) clear instructions for all three mods.

One thing [calebhollway08] would have done differently was to use something other than a 18650 battery for power, like a 21700. The question is, what will you do differently?

Maybe this is a little too small for you. If so, check out this EMP-protected cyberdeck.

Most of a three-key macro pad featuring a 3D-printed, LEGO-compatible plate.

3D-Printed Macro Pad Plate Is LEGO-Compatible

April 30, 2024 by Kristina Panos 2 Comments

We love LEGO, we love keyboards, and when the two join forces, we’re usually looking at a versatile peripheral that’s practically indestructible. Such seems to be the case with [joshmarinacci]’s LEGO-compatible 3D-printed plate for a three-key macro pad. For a first foray into scratch-built keyboard construction, we think this is pretty great.

The idea here is threefold: the plate holds the switches in place, negates the need for a PCB, and makes it possible to build the case completely out of LEGO. In fact, [joshmarinacci]’s plan for the keycaps even includes LEGO — they are going to 3D print little adapters that fit the key switch’s stem on one side, and the underside of a 2×2 plate on the other.

Although [joshmarinacci]’s plan is to design a PCB for the next version, there is plenty to be said for combining the plate and the PCB by printing guides for the wires, which we’ve seen before. We’ve also seen LEGO used to create a keyboard stand that fits just right.

Via KBD

A render of a BiC Cristal ballpoint pen showing the innards.

This Is How A Pen Changed The World

April 29, 2024 by Kristina Panos 75 Comments

Look around you. Chances are, there’s a BiC Cristal ballpoint pen among your odds and ends. Since 1950, it has far outsold the Rubik’s Cube and even the iPhone, and yet, it’s one of the most unsung and overlooked pieces of technology ever invented. And weirdly, it hasn’t had the honor of trademark erosion like Xerox or Kleenex. When you ‘flick a Bic’, you’re using a lighter.

It’s probably hard to imagine writing with a feather and a bottle of ink, but that’s what writing was limited to for hundreds of years. When fountain pens first came along, they were revolutionary, albeit expensive and leaky. In 1900, the world literacy rate stood around 20%, and exorbitantly-priced, unreliable utensils weren’t helping.

In 1888, American inventor John Loud created the first ballpoint pen. It worked well on leather and wood and the like, but absolutely shredded paper, making it almost useless.

One problem was that while the ball worked better than a nib, it had to be an absolutely perfect fit, or ink would either get stuck or leak out everywhere. Then along came László Bíró, who turned instead to the ink to solve the problems of the ballpoint.

Continue reading “This Is How A Pen Changed The World” →

An RGB LED clock that resembles a color blindness test.

RGB LED HexaClock Doesn’t Actually Light Up The Night

April 27, 2024 by Kristina Panos 11 Comments

Who says a clock can’t be both useful and beautiful? That seems to be the big idea behind the lovely little HexaClock from [Bulduper]. And boy, is it both.

Probably the most important part of this well-illuminated clock is the light sensor, which allows it to adjust the brightness automatically. If you’re not into that, well, there’s a really nice web app that’ll let you program the dickens out of it.

The brains of this thing is an ESP8266 on a custom PCB which controls the 127 individually addressable RGB LEDs. The clock may look large, but the big printed parts just fit on the bed of a Prusa i3. [Bulduper] used ABS because the LED strip and the PCB might get a little warm; they didn’t want to risk using PLA and having it turn into a Salvador Dali clock (although that could be cool).

Speaking of heat, make sure to use 18 AWG or thicker wires as [Bulduper] advises. LEDs may be efficient, but this clock uses lots of them! If you want to build one of these to bathe your wall in useful light, everything you need is available on GitHub. Watch HexaClock do its thing in the brief demo and walk-through video after the break.

If this is a little too bright for your tastes, check out this synesthesia clock.

Continue reading “RGB LED HexaClock Doesn’t Actually Light Up The Night” →