A business card-sized love detector in a 3D-printed package.

2024 Business Card Challenge: Who Do You Love?

June 10, 2024 by Kristina Panos 5 Comments

When you hand your new acquaintance one of your cards, there’s a chance you might feel an instant connection. But what if you could know almost instantly whether they felt the same way? With the Dr. Love card, you can erase all doubt.

As you may have guessed, the card uses Galvanic Skin Response. That’s the fancy term for the fact that your skin’s electrical properties change when you sweat, making it easier for electricity to pass through it. There are two sensors, one on each short end of the card where you would both naturally touch it upon exchange. Except this time, if you want to test the waters, you’ll have to wait 10-15 seconds while Dr. Love assesses your chemistry.

The doctor in this case is an RP2040-LCD-0.96, which is what it sounds like — a Raspberry Pi Pico with a small LCD attached. For the sensors, [Un Kyu Lee] simply used 8mm-wide strips of nickel. If you want to build your own, be sure to check out the build guide and watch the video after the break for a demonstration of Dr. Love in action.

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8-Tracks Are Back? They Are In My House

June 10, 2024 by Kristina Panos 55 Comments

What was the worst thing about the 70s? Some might say the oil crisis, inflation, or even disco. Others might tell you it was 8-track tapes, no matter what was on them. I’ve heard that the side of the road was littered with dead 8-tracks. But for a while, they were the only practical way to have music in the car that didn’t come from the AM/FM radio.

If you know me at all, you know that I can’t live without music. I’m always trying to expand my collection by any means necessary, and that includes any format I can play at home. Until recently, that list included vinyl, cassettes, mini-discs, and CDs. I had an 8-track player about 20 years ago — a portable Toyo that stopped working or something. Since then, I’ve wanted another one so I can collect tapes again. Only this time around, I’m trying to do it right by cleaning and restoring them instead of just shoving them in the player willy-nilly.

Update: I Found a Player

A small 8-track player and equally small speakers, plus a stack of VHS tapes. — I have since cleaned it.

A couple of weeks ago, I was at an estate sale and I found a little stereo component player and speakers. There was no receiver in sight. I tested the player with the speakers and bought them for $15 total because it was 75% off day and they were overpriced originally. While I was still at the sale, I hooked it up to the little speakers and made sure it played and changed programs.

Well, I got it home and it no longer made sound or changed programs. I thought about the play head inside and how dirty it must be, based on the smoker residue on the front plate of the player. Sure enough, I blackened a few Q-tips and it started playing sweet tunes again. This is when I figured out it wouldn’t change programs anymore.

I found I couldn’t get very far into the player, but I was able to squirt some contact cleaner into the program selector switch. After many more desperate button presses, it finally started changing programs again. Hooray!

I feel I got lucky. If you want to read about an 8-track player teardown, check out Jenny List’s awesome article. Continue reading “8-Tracks Are Back? They Are In My House” →

A stack of PCB business cards that can play Snake on an 8x8 LED matrix.

2024 Business Card Challenge: Snakes On A Business Card

June 2, 2024 by Kristina Panos No comments

Once [Lambert the Maker] saw the Arduboy, he knew the thing was ripe for remixing into a business card with an 8×8 LED matrix instead of an OLED screen. [Lambert] already has a PCB business card for work, but it looks like it doesn’t do anything. So this Snake-playing card is for their personal information.

The brains of this operation is an STM32F0, which required a bit of finesse when it came to programming the LEDs. According to the datasheet, the max current through a given GPIO pin is 30 mA. The LEDs are running at 20 mA through the limiting resistor, so the code only turns on one LED at a time and makes sure the previous one is off first. The whole screen is updated every 125 ms, and persistence of vision takes care of making the animation look right.

In the short videos after the break, you’ll see a preview followed by brief videos on versions one and two. The prototype was built in 2020, when the board house only offered green PCBs with their assembly service. Fast forward to 2024, when the board house is now offering colors other than green.

Version two is actually thinner than a credit card, and features tiny buttons instead of cap-sense pads for input. [Lambert] also added a floating ADC pin that acts as a random number generator, placing the apple in a new location every time the game is powered on.

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A small internet radio in 3D-printed case with a knob and an OLED screen.

GlobeTune Will Widen Your Musical Horizons

June 1, 2024 by Kristina Panos 12 Comments

Are you tired of the same old music, but can’t afford any new tunes, even if they’re on dead formats? Boy, do we know that feeling. Here’s what you do: build yourself a GlobeTune music player, and you’ll never want for new music again.

The idea is simple, really. Just turn what we assume is a nice, clicky knob, and after a bit of static (which is a great touch!), you get a new, random radio station from somewhere around the globe. [Alexis D.] originally built this as a way to listen to and discover new music while disconnecting from the digital world, and we think it’s a great idea.

[Alexis D.] has production in mind, so after a Raspberry Pi Zero W prototype, they set about redesigning it around the ESP32. The current status seems to be hardware complete, software forthcoming. [Alexis D.] says that a crowdfunding campaign is in the works, but that the project will be open-sourced once in an acceptable state. So stay tuned!

Speaking of dead-ish formats, here’s an Internet radio in a cassette form factor.

Hackaday Podcast Episode 273: A Tube Snoot, Dynamic Button Blobs, And Tokamaks Aren’t Whack

May 31, 2024 by Kristina Panos 8 Comments

This week, it was Kristina’s turn in the hot seat with Editor-in-Chief Elliot Williams. First up in the news: Germany’s solar and wind power generation have resulted in excess energy, which some people think is bad. In Hackaday news, the entries in the 2024 Business Card Challenge are really stacking up.

Then it’s on to What’s That Sound, which Kristina provided this week and managed to stump Elliot. 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 an improved spectrometer that wasn’t easy, and a rotary phone kitchen timer that kind of was. We’ll talk about badges turned invitations, reinventing rotary switches, and dynamic button blobs. Finally, we get the lowdown on the state of nuclear fusion, and posit why chatting online isn’t what it used to be.

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 273: A Tube Snoot, Dynamic Button Blobs, And Tokamaks Aren’t Whack” →

A PCB business card with a built-in 4x4 tic-tac-toe game on the back.

2024 Business Card Contest: A Game For Two

May 30, 2024 by Kristina Panos 2 Comments

If you want to make a good first impression on someone, it seems like the longer you can keep them talking, the better. After all, if they want to keep talking, that’s a pretty good sign that even if you don’t become business partners, you might end up friends. What better way to make an acquaintance than over a friendly game of tic-tac-toe?

This one will probably take them by surprise, being a 4×4 matrix rather than the usual 3×3, but that just makes it more interesting. The front of the card has all the usual details, and the back is a field of LEDs and micro switches. Instead of using X and O, [Edison Science Corner] is using colors — green for player one, and red for player two. Since playing requires the taking of turns, the microcontroller lights up green and red with alternating single-button presses.

Speaking of, the brains of this operation is an ATMega328P-AU programmed with Arduino. If you’d like to make your own tic-tac-toe business card, the schematic, BOM, and code are all available. Be sure to check out the build and demo video after the break.

Continue reading “2024 Business Card Contest: A Game For Two” →

Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The Auto Harp Typewriter

May 28, 2024 by Kristina Panos 6 Comments

An extremely large split keyboard with giant knobs, and pedals underneath the desk. — Image by [crazymittens-r] via reddit

Where do I even begin with this one? Let’s start with the reasoning behind this giant beast’s existence, and that is medical necessity. [crazymittens-r] needed something that would let them keep working, and after many hours and many versions, this is the current iteration of their ArcBoard, which looks like it could control a spaceship.

You can read all about this version on GitHub, but here’s the gist — you’re looking at a split keyboard with dual macro pads, rotary encoders, and a built-in trackball. And oh yeah, there are pedals, too. Those are a whole other thing.

In this revision, [crazymittens-4] said no to hand-wiring and instead went with custom flexible PCBs. The encoders now have push-button LED screens, and overall, there are “more LEDs than QMK can handle”. There’s even a secret keyboard within the keyboard! I can’t express how much I want to put my hands on this thing.

Continue reading “Keebin’ With Kristina: The One With The Auto Harp Typewriter” →