2024 Business Card Challenge: CardTunes Bluetooth Speaker

July 20, 2024 by Donald Papp 8 Comments

A business card form factor can be quite limiting, but that didn’t stop [Schwimmflugel] from creating CardTunes, an ESP32-based Bluetooth audio speaker that tried something innovative to deliver the output.

What’s very interesting about this design is the speaker itself. [Schwimmflugel] aimed to create a speaker out of two coils made from flexible circuit board material, driving them with opposite polarities to create a thin speaker without the need for a permanent magnet.

The concept is sound, but in practice, performance was poor. One could identify the song being played, but only if holding the speaker up to one’s ear. The output was improved considerably with the addition of a small permanent magnet behind the card, but of course this compromised the original vision.

Even though the concept of making a speaker from two flexible PCB panel coils had only mixed success, we love seeing this kind of effort and there’s a lot to learn from the results. Not to mention that it’s frankly fantastic to even have a Bluetooth speaker on a business card in the first place.

The 2024 Business Card Challenge is over, but judging by all the incredible entries we received, we’re thinking it probably won’t be too long before we come up with another sized-constrained challenge.

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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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Micro Jeep Model Kit Is Both Business Card And Portfolio

March 7, 2024 by Donald Papp 13 Comments

When finding work in product design and prototyping, two things are important to have at hand: a business card, and a sample of one’s work. If one can combine those, even better. Make it unique and eye-catching, and you’re really onto something. That seems to have been the idea behind [agepbiz]’s 1:64 scale micro Jeep model kit that serves as an “overcomplicated” business card.

Complete with box and labels in a shrink-wrapped package.

At its heart, the kit is a little print-in-place model kit that looks a lot like larger injection-molded model kits. Completing it is a custom-made box with custom labels, and it’s even shrink-wrapped. The whole thing fits easily in the palm of a hand.

There’s a lot of different tools effectively used to make the whole thing. The model card itself is 3D printed in multiple filament colors, and the box is constructed from carefully glued cardstock. The labels are custom printed, and a craft cutter (which has multiple uses for a hobbyist) takes care of all the precise cutting. It’s an awfully slick presentation, and the contents do not disappoint.

Get a closer look in the video, embedded just below. And if you like what you see, you’re in luck because we’ve seen [agepbiz]’s work before in this mini jet fighter, complete with blister pack.

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Minimal Tic Tac Toe Business Card

September 24, 2022 by Stephen Ogier 38 Comments

The PCB business card has long been a way for the aspiring electronics engineer to set themself apart from their peers. Handing out a card that is also a two player game is a great way to secure a couple minutes of a recruiter’s time, so [Ryan Chan] designed a business card that, in addition to his contact information, also has a complete Tic-Tac-Toe game built in.

[Ryan] decided that an OLED display was too expensive for something to hand out and an LED matrix too thick, so he decided to keep it simple and use an array of 18 LEDs—9 in each of two colors laid out in a familiar 3×3 grid. An ATmega328p running the Arduino bootloader serves as the brains of the operation. To achieve a truly minimal design [Ryan] uses a single SMD pushbutton for control: a short press moves your selection, a longer press finalizes your move, and a several-second press switches the game to a single-player mode, complete with AI.

If you’d like to design a Tic-Tac-Toe business card for yourself, [Ryan] was kind enough to upload the schematics and code for his card. If you’re still pondering what kind of PCB business card best represents you, it’s worth checking out cards with an updatable ePaper display or a tiny Tetris game.

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A Linux Business Card You Can Build

July 14, 2022 by Al Williams 22 Comments

It is a sign of the times that one of [Dmitry’s] design criteria for his new Linux on a business card is to use parts you can actually find during the current component shortage. The resulting board uses a ATSAMD21 chip and emulates a MIPS machine in order to boot Linux.

We like that in addition to the build details, [Dmitry] outlines a lot of the reasons for his decisions. There’s also a a fair amount of detail about how the whole system actually works. For example, by using a 0.8 mm PCB, the board can accept a USB-C cable with no additional connector. There is also a great explanation of the MIPS MMU and don’t forget that MIPS begat RISC-V, so many of the MIPS core details will apply to RISC-V as well (but not the MMU). You’ll also find some critiques of the ATSAMD21’s DMA system. It seems to save chip real estate, the DMA system stores configuration data in user memory which it has to load and unload every time you switch channels.

By the end of the post you get the feeling this may be [Dimitry]’s last ATSAMD21 project. But we have to admit, it seems to have come out great. This isn’t the first business card Linux build we’ve seen. This one sure reminded us of a MIDI controller card we once saw.

Laser-Cut Solder Masks From Business Cards

April 9, 2021 by Bryan Cockfield 22 Comments

There are plenty of ways to make printed circuit boards at home but for some features it’s still best to go to a board shop. Those features continue to decrease in number, but not a lot of people can build things such as a four-layer board at home. Adding a solder mask might be one of those features for some, but if you happen to have a laser cutter and a few business cards sitting around then this process is within reach of the home builder too.

[Jeremy Cook] is lucky enough to have a laser cutter around, and he had an idea to use it to help improve his surface mount soldering process. By cutting the solder mask layer into a business card with the laser cutter, it can be held on top of a PCB and then used as a stencil to add the solder paste more easily than could otherwise be done. It dramatically decreases the amount of time spent on this part of the process, especially when multiple boards are involved since the stencil can be used multiple times.

While a laser cutter certainly isn’t a strict requirement, it certainly does help over something like an X-acto knife. [Jeremy] also notes that this process is sometimes done with transparency film or even Kapton, which we have seen a few times before as well.

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Blister Pack With Jet Fighter Toy Is A Business Card

March 5, 2020 by Jenny List 20 Comments

In the world of business cards, it seems that for some people a white rectangle of card just doesn’t cut it any more. A card isn’t simply a means to display your contact details, instead it can be a way to show off your work and demonstrate to the world your capabilities. For [agepbiz] those are the skills of a 3D design specialist, so what better way to proceed than by distributing a 3D-printed example of his work? How to render that into a business card? Put it in a retail-style blister pack, of course. Take a look at the video below the break.

It’s an interesting process to follow, because there are certainly readers who will have toyed with the idea of selling their work, and this makes an attractive way to display a small assembly while still keeping it safe from damage. The toy – a small 3D-printed jet fighter with working swing wings that’s a masterpiece in itself – is laid on a backing card and a custom blister is glued over it. The manufacture of the printed backing card with a CNC card cutter is shown, followed by that of the blister with a custom SLA-printed mould being used to vacuum-form a sheet of clear plastic. Surprisingly the whole is assembled with just a glue stick, we’d have expected something with a bit more grab. The result is a professional-looking blister packed product of the type you wouldn’t bat an eyelid over if you saw it in a shop, and one of those things that it’s very useful to have some insight into how one might be made..

It’s possible this card might be a little bulky to slip in your wallet, but it’s hardly the only novelty card we’ve brought you over the years. Some of our most recent favourites run Linux or play Tetris.

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