Two sides of a business-card shaped device are shown. On the left, it’s clear that the device is about half a centimeter thick, with a large scroll wheel visible in the center. The device cover is 3D-printed in black plastic, and has cutouts to mark where three buttons ar. On the right, the underside of the device is visible. It is a black PCB, with white text giving contact information.

Building A Macro Pad Into A Business Card

August 31, 2025 by Aaron Beckendorf 10 Comments

A business card is a convenient way to share your contact information, but it’s unfortunately prone to being thrown away or forgotten. PCB business cards try to get around this problem, but while impressive, most won’t keep the recipient engaged for a very long time. [Cole Olsen]’s macro pad business card, on the other hand, might actually get regular use.

The card has three buttons and a rotary encoder as controls, with an RGB LED to indicate the card’s current mode. It can perform three sets of functions: general productivity, serving as a presentation remote, and controlling music. The scroll wheel is the main control, and can switch through windows, desktops, and tabs, page through slides, and control music volume.

The card itself is made out of a PCB, the exposed side of which contains [Cole]’s contact information, and the other side of which is covered by a 3D-printed case. As thick as it is, this might be stretching the definition of “card” a bit, but as a mechanical engineer, [Cole] did want to demonstrate some mechanical design. A nice!nano wireless keyboard development board running ZMK firmware reads the sensors and sends commands. Conveniently for a presentation remote, the card is powered by a rechargeable battery and can work wirelessly (as a side benefit, if a recipient were minded to get rid of this card, the lithium-polymer battery would probably substantially delay disposal).

[Cole] writes that he was inspired by many of the other impressive business cards we’ve covered. Some of the macro pads we’ve seen have been marvels of miniaturization in their own right.

An Engineer’s Emergency Business Card

December 2, 2013 by James Hobson 46 Comments

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We’ve seen lots of circuit board business cards before, but none quite like this. [Saar] calls it the Engineer’s Emergency Business Card.

Since he actually makes a living from making circuit boards, it made sense for him to make a truly functional card. But unlike some of the fancier cards we’ve seen, you can’t plug it into your computer, or even open a beer with it! In fact, all it does is light up when a voltage is applied across the main pins.

But wait — why are all the components in through holes? Well, according to [Saar], that’s because it’s designed to be the electrical engineers emergency kit!

When all hope is lost, the MacGuyver engineer could snap out one of the components and save the day. Recall the countless times you desperately needed a 1 KOhm resistor to fix an amplifier at a party, only to see the girl you were trying to impress slip away with an OCaml programmer? Never again with this little kit. You even have 2 cm of solder in there to make sure the connection’s electrically solid!

We love it. Whether or not anyone will ever successfully use it in an emergency situation such as [Saar’s] hypothetical one is another question altogether. But we do have to give him creativity points for it, the artistic traces look awesome!