The holidays always remind us of our favorite toys from when we were kids. Johnny Astro, an Erector set, and — of course — a Spirograph. [CraftDiaries] has an Arduino machine that isn’t quite a Spirograph, but it sure reminds us of one. The Arduino drives two stepper motors that connect to a pen that can create some interesting patterns.
The build uses a few parts that were laser cut, but they don’t look like they’d be hard to fabricate using conventional means or even 3D printing. The author even mentions you could make them out of cardboard or foamboard if you wanted to.
If you are tried of building things that fly, why not try a submarine like [DIYPerks] did? As you can see in the video below, the key is to control buoyancy, and the mechanism used is impressive. The sub has two giant syringes fore and aft to compress or decompress water. The plungers are now 3D-printed actuators that travel on a lead screw. Two high-torque motors and some batteries sandwiched in acrylic disks make up the rest. This is a big vessel — you won’t be trying this in your bathtub and maybe not even your pool unless it is a big one.
Of course, everything needs to be watertight. Instead of trying to waterproof a power switch, this sub uses a reed switch so that a nearby magnet can turn it on. Not an original idea, but we always think it is more elegant than seals and potting compounds.
This latest PCB artwork comes to you courtesy of [Arnov]. His Naruto nightlight is definitely going to get your anime-loving friends’ attention.
The LED illumination styles are controlled by an ATtiny13A microcontroller. He probably could have opted for a 555 timer with this one, but maybe he wanted easily programmable blinking patterns. He also programmed the ATtiny to read a small button which he used to cycle through different illumination styles. Finally, a small LiPo battery makes this project pretty portable, so you can reposition it freely around your work area as you might like.
With all that being said, the meat of this project is in the physical dimensional design of the PCB. [Arnov] was able to design the circuit board in the shape of Naruto’s head, with pretty good detail for his hair, eyes, and headband. If you’ve ever tried your own PCB art, you know that it can be a fairly onerous task. He creatively used the copper traces as features within the PCB, in this case, Naruto’s ninja headband. We thought the subtle decision of putting the LEDs on the backside of the PCB was smart as well. By doing so, he used the solder mask as a natural light defuser which really gave the PCB a cool, yellow glow. Carefully removing the copper layer and not using a copper pour really aided in the aesthetic. He was also smart to opt for yellow solder mask since Naruto’s hair is yellow.
There are many ways to create printed circuit boards, but one of the more traditional ways involves using boards coated with photoresist and exposing the desired artwork on the board, usually with UV light. Then you develop the board like a photograph and etch it in acid. Where the photoresist stays, you’ll wind up with copper traces. Hackers have used lots of methods to get that artwork ranging from pen plotters to laser printers, but commercially a machine called a photoplotter created the artwork using a light and a piece of film. [JGJMatt] sort of rediscovered this idea by realizing that a cheap laser engraver could directly draw on the photoresist.
The laser dot is about 0.2 mm in diameter, so fine resolution boards are possible. If you have a laser cutter or engraver already, you have just about everything you need. If not, the lower-power laser modules are very affordable and you can mount one on a 3D printer. Most people are interested in using these to cut where higher power is a must, but for exposing photosensitive film, you don’t need much power. The 500 mW module used in the project costs about fifty bucks.
Contactless payment by means of NFC-enabled bank cards has made our everyday transactions far more convenient over the last decade, but there still remains the tedious task of finding the card and waving it over the reader. Maybe embedded chips are a step too far for many of us, but how about a bank card in a wearable such as a ring? [Jonathan Limén] shows us how, by taking the NFC chip module from a bank card and mounting it on a ring with a wire coil antenna embedded within it.
The chip in a bank card comes mounted on a small thin PCB with contacts on one side and a coil on the other that serves as its antenna. It’s not sensitive enough to work reliably with most card readers, so the card incorporates a separate printed circuit layer that forms a large-sized tuned circuit which couples to the chip antenna. After taking us through the removal of the chip from the card with some acetone, he proceeds to create a replacement for the card antenna by winding a wire coil round the ring. This becomes a trial-and-error process, but in the end, the result is a working NFC payment ring.
We quite like this idea, but would be tempted to both take away some of the trial and error with a vector network analyzer, and run a couple of turns of the wire as a closer coupling coil for the chip. This is a subject we’ve looked at before here at Hackaday, and we wouldn’t mind having another go at it.
I have decided to make a career move and have accepted a position as Developer Relations Engineer at Golioth.io. I’m happy to announce that Elliot Williams will be the next Editor in Chief of Hackaday.
Right now I’m in my 13th year at Hackaday, having started in the summer of 2009. But like all of the Hackaday writing crew, I began as a loyal reader of the site. I remember hearing about Hackaday when Kevin Rose mentioned in on an episode of the old CNET TV program The Screensavers early in 2005. Having already been building robots and just starting on 8-bit AVR microcontrollers, Hackaday was exactly the source of new and interesting projects I was looking for.
An enormous amount has changed since then. When I started as a writer we had just stopped using black and white photos. A few articles later, we removed the CSS that forced all articles to be lowercase. When I became head editor in 2013 we stopped calling it Hack a Day in favor of Hackaday, and about a year later we overhauled the site, moving from green-on-black to yellow-on black and expanding the 470 pixel content width to 800. Progress.
What hasn’t changed is how we stay fresh. Hackaday has always trusted our writers to guide us by following their own interests. The people who write for Hackaday have far better things to do, but they use their writing as a creative outlet to focus on leveling up their skills, to discover new uses of available technology, and to share that energy with the greater Hackaday community. They live all over the world and work in many different fields. These experiences come together in there collective writings. I’m lucky to have this great group of writers, and so are you. When their time has ended, the hope is that a new group of readers will step up to the plate and make sure the good times never end.
Hackaday editors Elliot Williams and Mike Szczys get caught up on the week that was. People go to great lengths for video game saves, but this Pokemon hack that does hardware-based trade conversion between the Game Boy’s Pokemon 2 and Pokemon 3 is something else. Why do we still use batteries when super capacitors exist? They’re different components, silly, and work best at different things. Turns out you can study the atmosphere by sending radio waves through it, and that’s exactly what the ESA is doing… around Mars! And will machined parts become as easy to custom order as PCBs have become? This week we take a closer look at prototyping as a service.
Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!
