A curious custom that survives from the pre-computer era is that of the business card. If you walk the halls at a trade event you’ll come a way with a stack of these, each bearing the contact details of someone you’ve encountered, and each in a world of social media and online contact destined to languish in some dusty corner of your desk. In the 21st century, when electronic contacts harvested by a mobile phone have the sticking power, how can a piece of card with its roots in a bygone era hope to compete?
It’s a question [Anthony Kouttron] has addressed in the design of his thoroughly modern business card, and along the way he’s treated us to an interesting narrative on how to make the card both useful beyond mere contact details as well as delivering that electronic contact. The resulting card has an array of rulers and footprints as an electronic designer’s aid, as well as an NFC antenna and chip that lights an LED and delivers his website address when scanned. There are some small compromises such as PCB pads under the NFC antenna, but as he explains in the video below, they aren’t enough to stop it working. He’s put his work in a GitHub repository, should you wish to do something similar.
[Corey Harding] designed his business card as a USB-connectable demonstration of his skill. If potential manager inserts the card in a USB drive, open a text editor, then touches the copper pad on the PCB, [Corey]’s contact info pops up in the text box.
In addition to working as a business card, the PCB also works as a Tiny 85 development board, with a prototyping area for adding sensors and other components, and with additional capabilities broken out: you can add an LED, and there’s also room for a 1K resistor, a reset button, or break out the USB’s 5V for other uses. There’s an AVR ISP breakout for reflashing the chip.
Coolly, [Corey] intended for the card to be an Open Source resource for other people to make their own cards, and he’s providing the Fritzing files for the PCB. Fritzing is a great program for beginning and experienced hardware hackers to lay out quick and dirty circuits, make wiring diagrams, and even export PCB designs for fabrication. You can download [Corey]’s files from his GitHub repository.
[Sjaak], in electronic hobbyist tradition, started to design a PCB business card. However, he quickly became disillusioned with the coloring options made available by the standard PCB manufacturing process. While most learn to work with a limited color palette, [Sjaak] had another idea. PCB decals for full-color control.
As [Sjaak] realized early in his PCB journey, the downside of all PCB business cards (and PCBs in general) is the limited number of colors you can use which are dictated by the layers you have to work with: FR4, soldermask, silkscreen and bare copper. Some people get crafty, creating new color combinations by stacking layers for hues, but even that technique doesn’t come close to a full palette.
The commercial off-the-shelf out of the box solution [Sjaak] found was decal slide paper. For those of you not prone to candle making or car decorating, decals are printable plastic film that can be used to decorate ceramics, glass or other smooth surfaces. Both clear and white versions can be found in most hobby stores. Once obtained, an inkjet or laser printer can print directly onto the photo paper-like material, lending the decals an infinite range of colors.
[Sjaak] bought clear film and designed his PCB with black soldermask and white silkscreen. Once the PCBs had come in, [Sjaak] got to work applying the decals with a transfer method by placing one into water, waiting a bit until the decal lets loose and then are carefully applied to a PCB. [Sjaak] reports that the process is a bit trickery because the film is very thin and is easily crinkled. But, difficulties overcome, the PCB then needs to dry for twenty-four hours. From there, it’s into the oven for 10 minutes at 248 degrees Fahrenheit (120 degrees Celsius) followed by an optional clear coating. Although the process is a bit involved, judging from his pictures we think the results are worth it, producing something that would stand out; which, in the end, is the goal of a PCB business card.
Having seen a number of PCB business cards [Will] decided to go against the more popular choice of a micro-controller based design and show some character with a logic based finite state machine. [Will] uses a single 7-segment display to scroll through the letters of his name with a state machine that outputs the desired combination of 1’s and 0’s to the LED display each time the tactile button is pushed.
[Will] uses a 4-bit counter made up of D Flip-Flops for the clock signal as a conditional input to 6 of the 4-input AND gates. He doesn’t go into the painful details of displaying each character through the process (thankfully) but he does mention that he uses the Quine-McCluskey technique for reduction instead of Boolean algebra. Since his name is 11 characters long and the 4-bit binary counter goes from 0000 to 1111 leaving 5 more pushes of the button before rolling the count back to 0000, during which time the display is left blank. [Will] kindly includes the eagle and Gerber files for your downloading pleasure over at his blog if you’re interested in getting a little deeper into the design.
[Joe Colosimo] is putting on a show with his PCB business card project. The idea isn’t new, but his goal is to keep it simple and undercut the cost of all other PCB cards he’s seen. This is the third generation of the board design, and he’s just waiting on some solder mask solution before he tries running it through the reflow oven.
The first two prototypes used some through-hole parts. Notably, the battery was to be positioned in a circular cut-out and held in place by a metal strap and some bare wires. But he couldn’t quite get it to work right so this design will transition to a surface-mount strap for one side, and the large circular pad for the other. At each corner of the board there is a footprint for an LED. He tried milling holes in the board to edge-light the substrate. Now he just mounts the LED upside down to give the board a blue glow. The LEDs are driven by an ATtiny10 microcontroller which takes input from the touch sensor array at the bottom right.
He etched a QR code on the board which seems to work better than the milled QR experiments we saw back in April. The link at the top point’s to [Joe’s] main page on the card. Don’t forget to follow the links at the bottom which cover each part of the development more in-depth.
Hacker [12344321A] has built a clever open-source pen plotter having a frame made from odd-shaped PCB panels (Chinese). It holds an ordinary drafting pen and draws on a small writing platform 8 x 8 cm square. This is barely enough space to draw a business card, depending on which country you’re from. The motion appears to be provided by DVD stepper motor head positioning assemblies, and the controller is an ESP32-based GRBL 3-axis board. User control is via WiFi and the plotter can be seen in operation being driven from the user’s smartphone (see video on the project page above).
This looks like it would be an inexpensive build, and seems sturdy enough despite being literally held together by solder and paper clips. But be forewarned, the project is documented on an open-source hardware sharing site sponsored by EasyEDA called OSHWHub — the Chinese equivalent of their similar English-language OSHWLab. Hence all the notes are in Chinese, although Google translate can help here. [12344321A] provides all the engineering design files under GPL 3.0 license.
Thanks to [J. Peterson] for finding this project and bringing it to our attention via the tip line.
The festive season is often as good a reason as any to get out the tools and whip up a fun little project. [Simon] wanted a little tchotchke to give out for the holidays, so they whipped up a Christmas tree PCB that’s actually Arduino-compatible.
It’s a forward-looking project, complete with USB-C connector, future-proofing it for some time until yet another connector standard comes along. When plugged in, like many similar projects, it blinks some APA102 LEDs in a festive way. The PCB joins in on the fun, with white silkscreen baubles augmented by golden ones created by gaps in the soldermask.
An ATTiny167 is the brains of the operation, using the Micronucleus bootloader in a similar configuration to the DigiSpark Pro development board. It relies on a bit-banged low-speed USB interface for programming, but the functionality is largely transparent to the end user. It can readily be programmed from within the Arduino IDE.
It’s not an advanced project by any means, but is a cute giveaway piece which can make a good impression in much the same way as a fancy PCB business card. It could also serve as an easy tool for introducing new makers to working with addressable LEDs. Meanwhile, if you’ve been cooking up your own holiday projects in the lab, don’t hesitate to drop us a line!