The now-humble PCB was revolutionary when it came along, and the whole ecosystem that evolved around it has been a game changer in electronic design. But the PCB is just so… flat. Planar. Two-dimensional. As useful as it is, it gets a little dull sometimes.
Here’s your chance to break out of Flatland and explore the third dimension of circuit design with our brand new Flexible PCB Contest.
We’ve teamed up with Digi-Key for this contest. Digi-Key’s generous sponsorship means 60 contest winners will receive free fabrication of three copies of their flexible PCB design, manufactured through the expertise of OSH Park. So now you can get your flex on with wearables, sensors, or whatever else you can think of that needs a flexible PCB.
Remember when PCBs were green and square? That’s the easy default, but most will agree that when you’re going to show off your boards instead of hiding them in a case, it’s worth extra effort to make them beautiful. We’re in a renaissance of circuit board design and the amount of effort being poured into great looking boards is incredible. The good news is that this project proves you don’t have to go nuts to achieve great results. This stars, moons, and planets badge looks superb using just two technical tricks: exposed (plated) copper and non-rectangular board outline.
Don’t take that the wrong way, there’s still a lot of creativity that [Steve] over at Big Mess o’ Wires used to make it look this great. The key element here is that copper and solder mask placements have extremely fine pitch. After placing the LEDs and resistors there’s a lot of blank space which was filled with what you might see in the night sky through your telescope. What caught our eye about this badge is the fidelity of the ringed planet.
The white ink of silk screen is often spotty and jagged at the edges. But this copper with ENIG (gold) plating is crisp through the curves and with razor-sharp tolerance. It’s shown here taken under 10x magnification and still holds up. This is a trick to keep under your belt — if you have ground pours it’s easy to spice up the look of your boards just by adding negative-space art in the solder mask!
[Steve] mentions the board outline is technically not a circle but “a many-sided polygon” due to quirks of Eagle. You could have fooled us! We do like how he carried the circle’s edges through the bulk of the board using silk screen. If you’re looking for tips on board outline and using multiple layers of art in Eagle, [Brian Benchoff] published a fabulous How to do PCB art in Eagle article. Of course, he’s gone deeper than what the board houses offer by grabbing his own pad printing equipment and adding color to white solder mask.
The art was the jumping off point for featuring this badge, but [Steve] is known for his technical dives and this one is no different. He’s done a great job of recounting everything that popped up while designing the circuit, from LED color choice to coin cell internal resistance and PWM to low-power AVR tricks.
It was not too long ago that all PCB design packages were proprietary. Getting PCBs made was expensive, and if you tried to do this over the Internet, the best way was to download a board house’s proprietary software, design your board in their software suite, and send your boards off to be made. A 5 cm square board would cost two hundred dollars. I know this to be true because I’ve said it before, and no one has corrected me.
For this week’s Hack Chat, we’re talking Everything PCB with OSH Park. OSH Park is the leading creators of perfect purple PCBs. They have POGs, and for the last two weeks, they’ve been one of the few places you can send some Gerbers to and have it manufactured in a timely manner if you live in the US. Because China was closed.
For this week’s Hack Chat, we’re going to be talking about everything PCB. How do you do castellated holes? How do you mill slots and square or otherwise non-round holes? Internal cutouts? Stop mask expansion? Artwork? Panelization? Why purple? More POGs!
Our guests for this chat will be [Dan Sheadel] and [Drew Fustini] of OSH Park, and they’re going to be there answering all your questions. [Dan] has been around OSH Park from the beginning and enjoys designing tiny useless robots and mentoring students building better ones. [Drew] is an Open Source hardware developer, firmware designer, a BeagleBoard board member, and is usually found at hardware meetups wearing purple.
Model rocketry hobbyists are familiar with the need to roll their own solutions when putting high-tech features into rockets, and a desire to include a microcontroller in a rocket while still keeping things flexible and modular is what led [concretedog] to design a system using 22 mm diameter stackable PCBs designed to easily fit inside rocket bodies. The system uses a couple of 2 mm threaded rods for robust mounting and provides an ATTiny85 microcontroller, power control, and an optional small prototyping area. Making self-contained modular sleds that fit easily into rocket bodies (or any tube with a roughly one-inch inner diameter) is much easier as a result.
The original goal was to ease the prototyping of microcontroller-driven functions like delayed ignition or altimeter triggers in small Estes rockets, but [concretedog] felt there were probably other uses for the boards as well and made the design files available on GitHub. (Thanks!)
We have seen stackable PCBs for rocketry before with the amazingly polished M3 Avionics project, but [concretedog]’s design is much more accessible to some hobbyist-level tinkering; especially since the ATTiny85 can be programmed using the Arduino IDE and the boards themselves are just an order from OSH Park away.
There’s an inside joke among cyclists – the number of bikes you need is “n+1”, where “n” is your current number of bikes. The same probably also applies to the number of tools and equipment a hacker needs on their workbench. Enough is never enough. Although [David Johnson-Davies] has a couple of multimeters lying around, he still felt the urge to build a stand-alone continuity tester and has posted details for a super-simple ATtiny85 based Continuity Tester on his blog. For a device this simple, he set himself some tall design goals. Using the ATtiny85 and a few SMD discretes, he built a handy tester that met all of his requirements and then some.
The ATtiny85’s Analog Comparator function is perfectly suited for such a tester. One input of the comparator is biased such that there is a 51 ohm resistor between the input and ground. The output of the comparator toggles when the resistance between the other input and ground is either higher or lower than 51 ohms. Enabling internal pullup resistors in the ATtiny85 not only takes care of proper biasing of the comparator pins, but also helps reduce current consumption when the ATtiny85 is put to sleep. The test current is limited to 100 μA, making the tester suitable for use in sensitive electronics. And enabling the sleep function after 60 seconds of inactivity reduces standby current to just about 1 μA, so there is no need for a power switch. [David] reckons the CR927 button cell ought to last pretty long.
For those interested in building this handy tester, [David] has shared the Eagle CAD files as well as the ATtiny85 code on his Github repository or you could just order out some boards from OSHpark.
PCB art is getting better and better every year. This year, though, is knocking it out of the park. In March, [Andrew Sowa] turned me into money. More recently, [Trammell Hudson] has explored the layers of OSH Park soldermask and silk to create a masterpiece. Now, we’re moving up to full-blown art. [Blake Ramsdell] worked with OSH Park to create a full panel of art in gold, fiberglass, soldermask, and silkscreen. It’s 22×16 inches, and it’s fantastic.
Why does my circuit still work when I remove some caps? This question was posed to the EEVBlog forums, with a picture attached of the worst mess of wires I’ve ever seen. This is — supposedly — not a joke, and a complete, functional CPU built out of 74HC series logic on thirty or so solderless breadboards. A weird bonus of access to the tip line at Hackaday means everyone here becomes experts in the field of absurdly constructed electronics. Want to see the worst PCB ever? We’ve seen it. This is, without question, the most rats nest electronic project anyone has ever built.
[Adam West] died this weekend at the age of 88. [West] is perhaps best known for his performance in Lookwell as a crime-solving, washed-up TV action hero. He is survived by his wife, Marcelle, and six children.
A decade ago, while RISC architecture was busy changing everything and people were wearing Utilikilts without beards, hackers were doing something amazing. They repurposed off-the-shelf routers and turned them into what we would now call the Internet of Things. Need to set up a PBX? A Linksys router will do it. Want to drive a remote control car over the Internet? It’s your old friend, WRT54G.
Now that the Internet of Things is a thing, a few companies have realized people will buy bare bones router chipsets. It’s like an Arduino, or something, and it connects to the Internet. We’ll sell a million. Get Indiegogo on the phone.
The Onion Omega2 launched on Kickstarter last year, and so far has seen some success. They’ve shipped their units, and people are generally happy with them. One thing that wasn’t mentioned in the Kickstarter was the fundamental problem with the design. The pins on this seemingly breadboard-compatible dev board have a pitch of two millimeters. Horribly broken. Huge mistake. Terrible deal. Not the best people we have working on this.
After sending three dollars and twenty cents to OSHPark, [zach] had his pin adapters in hand. A few minutes with a soldering iron, and the Onion Omega2 is made compatible with every breadboard ever made.