Blinky Business Card Plays Snake And Connect Four

January 16, 2023 by Anool Mahidharia 6 Comments

There’s no better way to introduce yourself than handing over a blinky PCB business card and challenging the recipient to a game of Connect Four. And if [Dennis Kaandorp] turns up early for a meeting, he can keep himself busy playing the ever popular game of Snake on his PCB business card.

Quite wisely, [Dennis] kept his design simple, and avoided the temptation of feature creep. His requirements were to create a minimalist, credit card sized design, with his contact details printed on the silk legend, and some blinky LED’s.

The tallest component on such a design is usually the battery holder, and he could not find one that was low-profile and cheap. Drawing inspiration from The Art of Blinky Business Cards, he used the 0.8 mm thin PCB itself as the battery holder by means of flexible arms.

Connect-Four is a two player game similar to tic-tac-toe, but played on a grid seven columns across and six rows high. This meant using 42 dual-colour LED’s, which would require a large number of GPIO pins on the micro-controller. Using a clever combination of matrix and charlieplexing techniques, he was able to reduce the GPIO count down to 13 pins, while still managing to keep the track layout simple.

It also took him some extra effort to locate dual colour, red / green LED’s with a sufficiently low forward voltage drop that could work off the reduced output resulting from the use of charlieplexing. At the heart of the business card is an ATtiny1616 micro-controller that offers enough GPIO pins for the LED matrix as well as the four push button switches.

His first batch of prototypes have given him a good insight on the pricing and revealed several deficiencies that he can improve upon the next time around. [Dennis] has shared KiCad schematic and PCB layout files for anyone looking to get inspired to design their own PCB business cards.

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An ATX motherboard sits on a grey surface with the I/O in the foreground. Behind the I/O is a large image of Tux, the Linux penguin, taking up most of the PCB and winding its way around different components on the board. Tux is part of the PCB itself, with his feet, beak, and outline in gold, body in black silkscreen, and belly in green soldermask.

Designing Aesthetically-Pleasing PCBs

January 15, 2023 by Navarre Bartz 28 Comments

We’ve seen our share of custom PCBs here on Hackaday, but they aren’t always pretty. If you want to bring your PCB aesthetics up a notch, [Ian Dunn] has put together a guide for those wanting to get into PCB art.

There are plenty of tutorials about making a functional PCB, but finding information about PCB art can be more difficult. [Ian] walks us through the different materials available from PCB fabs and how the different layer features can affect the final aesthetic of a piece. For instance, while black and white solder mask are opaque, other colors are often translucent and affected by copper under the surface.

PCB design software can throw errors when adding decorative traces or components to a board that aren’t connected to any of the functional circuitry, so [Ian] discusses some of the tricks to avoid tripping up here. For that final artistic flair, component selection can make all the difference. The guide has recommendations on some of the most aesthetically pleasing types of components including how chips made in the USSR apparently have a little bit of extra panache.

If you want to see some more on PCB art, check out this work on full-color PCBs and learn the way of the PCB artist.

NE555-Based Electronic Dice

December 11, 2022 by Dave Walker 14 Comments

It has become a bit of a running joke in the Hackaday community to suggest that a project could or should have been done with a 555 timer. [Tim] has rather taken this to heart with his latest Electronic Dice project, which uses three of the venerable devices.

If three seems like a lot of 555s to make an electronic die, then it may be worth considering that the last time we shared his project he was using 22 of them! Since then, [Tim] has been busy optimising his design, whilst keeping within the constraints of an old-school through-hole soldering kit.

Maybe the most surprising thing about this project is the purpose to which the NE555 devices are pressed. Rather than using them for their famous oscillation properties, they are in actual fact just being used as Schmitt Triggers to clean up the three-phase ring oscillator that is constructed from discrete transistors and passives.

scope trace of the electronic dice ring oscillator — Simulation trace of the three-phase ring oscillator before Scmitt Trigger stages

The ring oscillator cleverly produces three phase-shifted square waves such that a binary combination of the three phases offers six unique states. Six being the perfect number for a dice throw, all that then remains is to figure out which LEDs need to be switched on in which state and wire them up accordingly.

To “roll” the dice, a push-button powers up the oscillator, and stops it again when it is released, displaying the random end-state on the LEDs.

It can be fun to see what can be done using old technology, and educational to try to optimise a design down to the fewest parts possible.

[Tim]’s earlier project is here if you want to see how the design has evolved. The documentation on both of these iterations is excellent and well worth a read.

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Taking (Good) Pictures Of PCBs

December 1, 2022 by Bryan Cockfield 18 Comments

Snapping pictures is not technically difficult with modern technology, but taking good photographs is another matter. There are a number of things that a photographer needs to account for in order to get the best possible results, and if the subject matter isn’t particularly photogenic to start with it makes the task just a little more difficult. As anyone who’s posted something for sale online can attest, taking pictures of everyday objects can present its own challenges even to seasoned photographers. [Martijn Braam] has a few tricks up his sleeve for pictures like this in his efforts to photograph various circuit boards.

[Martijn] has been updating the images on Hackerboards, an online image reference for single-board computers and other PCBs, and he demands quality in his uploads. To get good pictures of the PCBs, he starts with ample lighting in the form of two wirelessly-controlled flashes in softboxes. He’s also using a high quality macro lens with low distortion, but the real work goes into making sure the image is sharp and the PCBs have well-defined edges. He’s using a Python script to take two pictures with his camera, and some automation in ImageMagic to composite the two images together.

While we’re not all taking pictures of PCBs, it’s a great way of demonstrating the ways that a workflow can be automated in surprising ways, not to mention the proper ways of lighting a photography subject. There are some other excellent ways of lighting subjects that we’ve seen, too, including using broken LCD monitors, or you can take some of these principles to your workspace with this arch lighting system.

Aesthetic PCB Design Tips For Improved Functionality

November 29, 2022 by Dave Rowntree 9 Comments

Those of us hardware types that spend a lot of time designing PCBs will often look at other peoples’ designs with interest, and in some cases, considerable admiration. Some of their boards just look so good. But are aesthetics important? After all, for most products, the delicate electronic components on that PCB are tucked safely inside a protective enclosure. But, as [Phil’s Lab] explains, aesthetic PCB designs can lead to functional improvements, such that better-looking designs are also better performing, in terms of manufacturability (and therefore yield), electromagnetic compatibility (EMC), and several other factors that can be important.

First off, making a PCB easy to read and using sane placement of components and connections will speed up debugging by reducing errors. Keeping a consistent and not too-tight placement grid can give the pick and place machine an easier task, and reduce solder issues during reflow. But there are also more serious concerns, such as the enforcement of design partitionings — such as keeping analog circuits together and away from noisy power and digital areas — which can make the difference between functioning within specification, and failure.

The video goes into a few other interesting tips, one highlight is using a ground-tied PCB perimeter zone, with wavelength-of-interest via stitching. This will reduce EMC side emissions from the power plane, but also if you select an appropriate surface finish, and keep the solder mask open, you’ve got a free, full perimeter contact to ground your scope probe. Oh, and it looks good too.

Hackaday is no stranger to beautiful artistic PCBs, like the work of [Saar Drimer] and many others. But if one PCB doesn’t cut it for your needs, there’s always the ‘Oreo’ construction to consider.

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Racing Cars On A PCB

November 24, 2022 by Bryan Cockfield 14 Comments

Carl Friedrich Gauss was, to put it mildly, a polymath responsible for a large percentage of the things we take for granted in the modern world. As a physicist and mathematician he pioneered several fields of study including within the field of magnetism. But since he died decades before the first car was built, it’s unlikely he could have imagined this creation, a magnetic slot-car race track called the Gauss Speedway by [Jeff McBride], which bears the name of the famous scientist.

The Gauss Speedway takes its inspiration from a recent development in robotics, where many small robots can travel around a large area with the help of circuit traces integrated into their operating area. With the right current applied to these traces, magnetic fields are generated which propel the robots. [Jeff] wanted to build something similar, integrated into a printed circuit board directly, and came up with the slot car idea. The small cars have tiny magnets in them which interact with the traces in the PCB, allowing the cars to move with high precision around the track. He did abandon the traditional slot car controller in favor of a push-button style one directly on the PCB too, which means everything is completely integrated.

While this was more of a demonstration or proof-of-concept, some of the features of this style of robot can be seen in this video, which shows them moving extremely rapidly with high precision, on uneven surfaces, or even up walls. Magnetic robots like these are seeing quite a renaissance, and we’ve even seen some that use magnetism to shape-shift.

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Rubber Stamping Your Way To Custom PCBs

October 19, 2022 by Lewin Day 24 Comments

Many of us now outsource PCB production to board houses overseas, which offer high-quality boards with increasingly impressive turnaround times. You might still brew up your own PCB, though, and a reader found this great old hack from [William Hare] that might be worth a look.

Forget toner transfer or marker pens — this build is all about speed. [William] decided to use a rubber stamp to quickly transfer ink to a copper board that can then be etched to produce a PCB. It’s simple and straightforward enough. We’ve used the same technique for silkscreen and pad art, but never as an etch resist.

The trick is to make several rubber stamps with different circuit elements, though. The genius part is that you can then assemble a PCB by simply stamping down the various circuit components you need. The boards will still need to be drilled if you’re working with through-hole parts, but tipster [Shri] notes that the technique is super useful for producing single-sided surface mount boards.

We’ve seen some other unique methods to producing PCBs at home, such as using a 3D printer to help out. If you’ve got your own innovative homebrew PCB hacks, be sure to drop us a line!

Thanks [Shri Hari Ram] for the tip!