Argentum is like a 3D printer for PCBs

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Cartesian Co.’s rapid prototyping machine is putting the “print” back in printed circuit boards.

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Despite how far 3D printing has come over the past couple of years, a number of startups have been looking for new ways to take it one step further. Rather than just spit out odds and ends in plastic, what if you could quickly extrude something a bit smarter, like circuit boards, on demand? That’s the idea behind Cartesian Co.’s rapid prototyping machine dubbed Argentum.

While it admittedly may not be the first startup to come up the idea of putting the “print” back in printed circuit boards, it is among the very few that have squeezed the price down to Maker-friendly levels. If the New York-based company sounds familiar, that’s because there’s a good chance you may have come across their incredibly successful Kickstarter campaign back in 2013 — called EX¹ at the time — which garnered over $137,000. Since then, Cartesian Co. has shipped nearly 200 units and has worked diligently on improving the reliability of its inks and substrates

Simply put, Cartesian Co. is hoping that Argentum will transform electronics and prototyping in the same way that conventional 3D printing revolutionized traditional manufacturing. The gadget works by layering down silver nano-particles through an inkjet process onto almost any substrate you could imagine.

First, a user must generate the artwork for their electronics design. From there, the image is exported and processed by the Argentum’s custom control software, which generates code that the printer can directly interpret. The printer can then receive the command file via a USB interface, through the stock SD card port or even through a web interface if the user has the RasPiFi add-on. This enables a Maker to go from a circuit board design to reflowing solderable PCBs in a matter of minutes, without all the overhead costs of low production runs — something that is tremendously valuable for hobbyists, engineers and startups on a limited budget with time constraints.

“This lets you create electronics, just as you’ve envisioned — wearable electronics, paper circuits, printed computers or whatever you imagine. A 3D printer creates the objects of your imagination; the Argentum lets you create the electronics of your imagination,” company co-founder Ariel Briner explains.

So, how does the innovative machine work? Essentially, two inkjet cartridges (similar to the ones in a standard printer) print images on a substrate, but instead of ink they lay down two different chemicals. When these two chemicals mix, a reaction occurs, producing silver nano-particles, leaving a silver image. Aside from only conventional circuit board materials, the Argentum can employ a variety of other substrates that might not be commonly associated with electronic circuitry. These include paper, wood, ceramic, Kapton, fiberglass, and looking ahead, fabric.

Take this “Simon Says” game, for example, that the team printed on fiberglass. It has an ATtiny4313 running Arduino and capacitive touchpads for user input.

“One capability of the Argentum that we’re really excited about is the ability to print straight onto fabric. Anyone who has used conductive thread will tell you how frustrating it is when the thread breaks but you can’t find the break! With the Argentum, you can print circuits straight onto the material of your choice,” Briner adds.

The electronics, including an ATmega2560 at its core, are housed inside a sleek, black acrylic enclosure that would be an aesthetically-pleasing mainstay in any Makerspace. The Argentum boasts a build area of 6.7” x 4” with an overall footprint of 16.9” x 14.1” x 5.2” — meaning, it will fit perfectly on a workbench or desktop. On top of that, the Cartesian Co. crew offers complete flexibility with its software from importing an image with default settings and clicking print, to exerting control over every printing variable.

The device prints at a native resolution of 300DPI, which can be enhanced to 600DPI using its software. What’s more, Argentum can print, assemble and test a circuit board in less than two hours, while eliminating the hassle and dangers typically associated with hazardous chemicals.

“This means you will be able print footprints as fine as TSSOP (0.65mm pitch) on our treated G10 substrate and SOIC (0.8mm pitch) on all our other materials including polyimide, linen paper, stone paper and more,” the team writes.

Circuits printed on G10, polyimide and paper can be hand soldered as well. This will, of course, require a bit more skill and needs to be done relatively fast to avoid damaging the silver traces.

Intrigued? Head over to Cartesian Co.’s official site to learn more, and pre-order your own unit for $1,599. Delivery of the next batch is slated for September 2015.

 

IR reflow oven for your prototype PCBs

When you use solder paste to assemble your prototype PCB (printed circuit board) you need a stencil or hypodermic needle to apply the paste to the pads on the board. Then you use an IR (infra-red) reflow oven to melt the solder. Scott Fritz, an Atmel IC designer on the third floor, found this neat home-made controller that turns a cheap toaster oven into an IR reflow oven. I assume the name Reflowster is a combination of the words “reflow” and “toaster.”

The Reflowster will do closed-loop control of a cheap toaster over so you can do IR reflow soldering on your prototype circuit boards.

The Reflowster is an Arduino-based controller that that gives you predicable and repeatable heating and cooling profiles to melt the solder paste and connect up all the components on your board. They got their start on Kickstarter, and have actually shipped, so all the Kickstarter people are rewarded. Now the Reflowster folks are starting to offer the product to the general public.

The Reflow controller V3 PRO from PCB POOL in Europe is another product meant to work with a toaster oven.

I have mentioned a similar reflow controller made by the fine people at PCB-POOL in Europe. That article also described how my buddy Wayne Yamaguchi was using a toaster oven a decade ago to make his PCBs. Wayne did not use a controller. He just did a whole bunch of tests until he was satisfied he was getting good whetting and solder fillets on his circuit boards.

The great thing about the Reflowster is that it is a closed-loop controller. It is actually measures the temperature of the oven, and then controls the power to it so that the heating and cooling match the profiles recommended by component makers like Atmel (pdf).

Precise temperature control is needed to do quality lead-free soldering.

While I love, admire, and respect my buddy Wayne Yamaguch’s “theory of experiments” approach, you might really need the Reflowster. If you want to use different ovens, or have changing wall voltage, or the boards you are soldering are different sizes or have a different set of components on them, you want a closed-loop controller. If the chips have a big pad on the bottom, the die-attach-paddle, you need reflow. The other big factor is lead-free solder. Many of the crazy analog engineers I hang out with still use tin-lead solder for prototypes. It looks better, it feels better, and lead solder is more reliable. We also pull the solder off the reel by biting it gently and tugging, so we don’t have to set the soldering iron down. Lead poisoning might explain why we are all crazy. But if you are sane and insist on using lead-free solder, the preciseness of reflow control is important.

Solder paste application is like silkscreening T-shirts. Instead of silk the stencil is stainless steel. Instead of ink you use solder paste. Instead of T-shirts you do printed circuit boards.

Solder paste has its own hassles. You should refrigerate open containers so the little solder balls do not oxidize and change the reflow parameters. I am not sure the same caveat applies to when you use a big hypodermic to apply the solder paste. There the hassle is you have to do it one pad a time. A solder stencil is a thin stainless steel sheet where the PCB fab house has etched through all the areas where there is supposed to be solder. Sometimes called the “cream layer” Its not exactly the solder mask art, but it is pretty close, depending on your particular design. I know you can set up OrCAD 9.2 to do it, and I am sure other CAD packages can make it, or the PCB fab house can create one from your solder mask layer art.

Here is a typical solder stencil from Stencils Unlimited. With one swipe of a squeegee you apply solder paste to the pads for your chips and passive components.

The fine folks at Sunstone used to offer a free stencil, now it looks like they charge a little. Most fab houses can supply one. Assembly houses like Screaming Circuits or Advanced Assembly have the relationships with board houses to they can make your stencil when they assemble your boards. If you are really masochistic, and have a high-powered CO2 laser cutter handy, you can make your own stencils. You can also live in a cave and use flint tools, but I prefer to operate a little higher on the food chain. The LPKF laser mill can make your stencils as well.

This solder stencil from Proto-Advantage lets you apply solder paste for a QFN-32 chip.

There are also hybrid approaches. You can buy cheap solder stencils just for high-pin-count chips on your board. You squeegee the solder paste onto the board for each of those parts, Then you can use a hypodermic for the passive components or hand-solder them after you reflow the big chips.

If you are a big-time engineer on a big-budget project then just contact Screaming Circuits or Advanced Assembly or you local board assembly house (not PCB fab, but board assembly). I know Screaming Circuits can do it all since they have teamed up with Sunstone and Digi-Key. Just send Screaming Circuits the fab Gerber and fab files which they send to Sunstone, the assembly drawing and insert file which they use themselves, and the BOM (bill of material) they order the parts with from Digi-Key. They can do quick-turn and they can ship anywhere in the world.

So the prototyping ecosystem is like this:

• If you are a hobbyist use DIP (dual-inline plastic) chips with 0.1 inch lead spacing and through-hole passive components. You might use surface mount chips on DIP breakout boards.
• If you are a pro-hobbyist or low-budget engineer buy a temperature-controlled Weller soldering iron or a Metcal and a good stereo microscope. Now you can hand-solder surface mount boards. For chips with bottom pads you have to either heat the whole chip with a big soldering iron, use a heat gun, or try to wick the solder in from vias you design in on the backside of the board.
• If you are a hobbyist doing low-volume manufacturing or a medium-budget engineer, go to solder stencils and reflow ovens.
• If you are a hobbyist that hit it big or a big-budget engineer, use the board house to order the parts, get the PCB fab, and assemble and maybe even test your board.

TQM Solutions knows that total quality management means you not only have a mountain of documentation, but that you organize that mountain.

Note that last item. See, as an engineer, your real job is to make a set of documentation so the design can get manufactured by non-engineers and non-technicians and non-hobbyists. Its nice you are a hands-on person. Heck, its critical you are a hands-on person to be a good engineer. But your real responsibility is making sure the CAD files are correct. it might speed things up if you make a first-spin board yourself, and its neat if you make the board on an LPKF mill and you can get parts from the factory floor or Radio Shack or a salvage yard.

I used to design products with parts I found cheap at places like Weird Stuff Warehouse in Silicon Valley. Then one of my designs went to production but Weird Stuff had sold off all the parts I had used. Now I select parts from distributors.

The great thing about using Screaming Circuits and Sunstone and a distributor like Mouser or Arrow or Newark or DigiKey is that you are proving out your documentation. You make it clear to Screaming Circuits that if your pick-and-place insert file has mistakes they tell you, you fix them and they use that file. This way, when they see that the part origin for a DPAK is at the pad and not the part center, they know the vacuum picker cannot pick it up, so you catch that AND FIX IT. If your Gerbers have problems you make sure Sunstone tells you, or you use the free DFM (Design for manufacturing) check offered by Advanced Circuits. Then you FIX THE FILES. Same deal for any BOM mistakes. Make sure somebody tells you so you can FIX THE FILE, and not the text file, you fix the CAD file in OrCAD or Altium or whatever, so it spits out a perfect BOM.

Now when you send the CAD files to China to get assembled on the cheap, you know the files are correct. Anything less and you are not an engineer, you are an amateur. Proto Express even works with a Chinese partner to ensure you can get cheap-high volume boards that work as well at the Proto-Express boards made right here in Silicon Valley.

The oqo Model 2 used a Via processor. The third model with an Intel Atom never got built since they ran out of money (courtesy Engadget).

This level of diligence and exactness is critical. I worked at oqo, a San Francisco start-up that made the first palm-top computer that ran real Windows OS. The first model was based on the Transmeta “emulated” x86 processor. The second model used a Via chip. Lesson there is never base a business plan on being smarter than Intel. The third prototype never went into production. I had left the company for National Semiconductor, but pals there told me they used an Intel Atom processor and it was a real product that could really work good. But they were running out of money. So I assume in a big rush, they sent the design to the Chinese contract manufacturer. A pal familiar with the company told me oqo had to fly out an engineer to China and there were 1000 ECOs (engineering change orders) to get the design ready for high-volume manufacturing. One thousand mistakes. Now it probably didn’t matter, but its nice to think that if they had scrubbed the CAD files, the fab, the assembly, and the rework documentation through a US quick-turn prototype manufacturer, and fixed most of those mistakes, then maybe they could have gotten that product to market and saved the company.

This is a perfect example of the asymmetric respect problem in engineering. The Chinese manufacturing engineers respected those high-tone former Apple designers at oqo. But the oqo engineers may have thought manufacturing was some triviality and beneath them. Perhaps they thought any idiot should be able to do it. Sorry. Wrong. Dead wrong. Dead just like oqo is today. You need to be every bit as smart, clever, and creative to do manufacturing and test as to do design work. When you take a product all the way to production, you will learn to respect everybody involved. Respect the planners, the clerks, the assemblers, and ALL the engineers. So be a good and respectful design engineer and make sure your CAD files are a good as they can be before you send them out for production. That is your responsibility, not a Flextronics responsibility.

The cover of my mentor Bob Pease’s book Troubleshooting Analog Circuits has one of his “airball” prototypes on the cover. Application engineers like Bob can do proof-of-concept, but don’t try sending this out for high-volume manufacturing.

So like all things, prototyping has an analog continuum to it, There is a place for quick-and dirty hacks. There is place for super-diligence. And there is a whole spectrum of tradeoffs for an appropriate design effort in between those poles. Just don’t do some rush-job today that you just know will bite you a few months later.

[Update] I showed this post to Wayne Yamaguchi and he had this great comment:

“One of the major drawbacks to solder paste is the shelf life.  No matter how you buy it, the container and contents will go bad in about 6 months time, even in the refrigerator.  It’s the flux that ages and slowly solidifies making the reflow consistency different over time.  It’s just a real pain to dispense the paste with a tiny-tip syringe when it it’s fresh, and even worse when it has aged a bit. If I recall correctly, the smallest syringe runs about $50.00.  You can solder a lot with that but if you only make one proto this is an expensive proposition.

“Mine tends to absorb water over time and this makes it pop when reflowing, blowing off chunks of solderpaste in all directions. I can hand-solder 0402 and DFN parts with the soldering iron.  I only need the hot-air station for pads that are not exposed, like power pads and some SMT inductors. I would recommend a really good soldering iron or two, and a general-purpose hot air station if you want to hand-solder small runs of boards. You will need one with a 0.2mm tip or smaller for the leadless and 0402 parts.

“I prefer to still use leaded solder.  It solders at a lower temp and the chemicals are less caustic, unlike the solder flux used for leadless solder.  Unless I have to, I try to use “no clean” flux and occasionally will use Kester 331 (IIRC) for gold-plated pads.

“Good stencils are cut non-vertical.  The edges are beveled so the bottomside is slightly larger than the top, making the solderpaste less resistant to sticking to the stencil.  Hopefully, when you lift the stencil the solderpaste adheres to the PCB and not the stencil.  I’ve never actually seen the process, but, I always imagined  that the paste would not all tranfer.  I guess it works.  Just doesn’t work in my mind.  The bevel is only 5-10 degrees.  Hardly noticeable by the eye, but, I guess it makes a difference.

“Another gotcha will come when you doing rework.  You remove the part in question and/or use solderwick to clean the pads.  If you try and apply solderpaste right away the residual heat will outflow the flux from the syringe tip which is most frustrating as now the tip is full of paste with no flux.  When this occurs it is like concrete and won’t flow.  It is possible to drain more than the tip into the larger part of the syringe tube rendering the whole syringe load bad.  You can unscrew the tip and plunge out the bad material, but, who knows if you now have the right ratio of flux to solder anymore?  If this is the tube from the vendor you can kiss $50.00 down the drain.  If you transferred solderpaste to a smaller syringe the loss is less than $50.00.”

I guess all those years at HP and Agilent, and then being in business for himself gave Wayne a valuable perspective on prototyping. Many thanks to him, and add you own comments below.

IR reflow in your home lab

While at the EELive! conference last week I met up with the PCB-POOL folks. I first heard about this PCB fab house from my buddy Wayne Yamaguchi. Despite their being located in Ireland, Wayne said they were getting the prototype boards to him in a week. Best yet, at that time, they did not charge extra for non-rectangular board shapes, and Wayne’s boards were all round, used to convert a Maglite flashlight to an LED flashlight.

What caught my eye at the PCB-POOL booth at EELive! was a card that had a toaster oven picture and the headline: “Create your own solder reflow station.” Now it was Wayne that tipped me off about doing reflow for prototypes in your garage. He too used a toaster oven. He just did a few experiments on when to turn it on, when to put in the PCB and when to turn it off. He said he decent results, but the problem with this is that it is an essentially uncontrolled process.

This card was from the PCB-POOL booth at the EELive! conference in 2014.

Enter PCB-POOL. Sure, they sell the toaster ovens. The real deal is they sell the third version of a controller so you can create a profile on your toaster oven. Please don’t use the toaster in your kitchen; flux is not the best butter for your English muffins. So like the picture explains, buy the reflow controller from PCB-POOL for $315, get a brand new toaster oven for 80 bucks, and if you order 5 PCBs from PCB-POOL, they cost 30 dollars each, and PCB-POOL gives you a free solderpaste stencil with the order.

A solder stencil is a thin steel sheet that is laser-cut to have the pads of your circuit board. You carefully position it on top of your bare PCB and then you can squeegee solder paste over it, like doing ink on a silkscreen. Only instead of ink, you are deposing a thin coating of solder paste on all the places where surface-mount parts will mount.

This is a solder stencil, with laser or photo-etched cutouts for where you will put solder paste on your prototype PCB.

Now that you have the solder on the pads, the surface mount components will just stick to the board and self-align as the solder melts. Sometimes you can even put parts on both sides and use the solder paste to suspend the parts on the bottom. For heavier parts on the bottom you need a dab of hot-wax or silicon to keep the part in place through the reflow process.

The great thing is that your reflow process has a real temperature profile, like it should. I assume the controller has a SCR or maybe it is just a bang-bang controller that cycles power to achieve a given profile and temperature. The more control you have the more repeatable your process. One nice thing about using the stencil at all is that it proves out your CAD padstacks. If you made some part and forgot to put a solder paste element in the pads for that part, you will realize it really quick when you see there is no solder paste on those pads. This lets you fix your CAD file before it goes into production.

The next level would be to send the whole board to an assembly house like Screaming Circuits in Oregon or Advanced Assembly in Colorado (right down the street from Advanced Circuits, but a different company). Indeed, the first outfit I saw giving out free stencils was Sunstone, which is near Screaming Circuits in Oregon. When you send your fabbed boards to these small-lot assembly houses you are doing more than just sparing yourself the headache of soldering up the board yourself. You are proving out the solder-paste file from your CAD program, as well as the “insert” file as OrCAD 9 calls is, what the pick-and-place machine uses to place your components on the board before reflow soldering. Now you might find that the TO-220 parts have an insert location way off to the side and won’t let the machine vacuum pick them up. So when the nice folks at Screaming Circuits explains this to you, you can fix the CAD files before they go into higher volume production. The real job of an engineer is to make a set of comprehensible coherent documentation that lets the manufacturing world make lots of your design. This is every bit as important as getting the chips to work and the firmware to run.

Most all the fab houses can hook you up with short-run assembly. Some can have your prototypes hand-soldered; many need 3-feet of tape and reel parts so it fits in their machine. That is the cool thing about Screaming circuits, they have adapted their machines so you put in 4 or 5 pieces on some DigiKey cut-tape and make just 5 boards with no parts left over. And don’t forget my pals at Sierra Proto Express. It was Ken Bahl who created the whole short-run prototype concept 20 years ago. These days they specialize in high performance boards, down to a few mills or many ounces of copper along with blind and buried vias. Best yet, they have a partner in China, so when you are ready for high-volume, they can guarantee the partner can make any board you had made at Proto Express.

From Shanzhai to OSHW: The Maker Movement in China

Although the Maker and open source hardware movements are a global phenomenon, the DIY culture in China can actually be traced back to the ancient concept of Shanzhai. As Gabrielle Levine, the newly appointed president of the Open Source Hardware Association (OSHWA) notes, China is going to be a huge driving force in the open source hardware landscape.

“There are many similarities between [the local concept of] Shanzhai and the open source hardware community,” Gabriella Levine told OpenElectronics in February. “Both Shanzhai and open source hardware projects borrow information, tools, source code, CAD files and techniques; both improve upon other’s work to accelerate development.”

SeeedStudio founder Eric Pan expressed similar sentiments during a recent interview with Atmel’s official blog, Bits & Pieces.

“MakerSpaces will likely enable a new wave of tech startups in China as in the US,” he confirmed.

“Clearly, hardware development is becoming a more agile process with the aid of [open source] prototyping tools like RepRap and Arduino boards – both of which are helping to facilitate innovation across the world and particularly in China.”

Similarly, David Li, co-founder of Shanghai’s first Maker Space, told The Economist that the DIY movement has inspired the creation of legitimate and innovative products, with socially progressive Makers teaming up with more traditional manufacturers in China.

We at Atmel are at the strategic heart of the international Maker Movement, with a comprehensive portfolio of versatile microcontrollers (MCUs) that power a wide range of Maker platforms and devices, including 3D printers (MakerBot Replicator 2 and RepRap), the vast majority of Arduino boards, as well as Adafruit’s Gemma, Trinket and Flora platforms.

Indeed, Arduino boards are currently used by millions of Makers, engineers, schools and corporations all over the world. At least 1.2 million Atmel-powered Arduino boards have been sold to date, with the ATmega328-based Uno being a particular Maker and prototyping favorite. Of course, stand-alone AVR microcontrollers like the tinyAVR lineup are also popular amongst the DIY crowd.

As we’ve previously discussed on Bits & Pieces, an increasing number of Makers are kicking off project prototyping with Atmel-based Arduino boards. Concurrently, we are also seeing a jump in professional engineers relying on Atmel-powered Arduino boards to create initial models for their devices, platforms and solutions.

Atmel-powered uArm

According to Gartner, 50% of companies expected to help build the rapidly evolving Internet of Things have yet to coalesce. This is precisely why Atmel views China’s Maker Movement as one of the primary tech incubators for future IoT companies and devices, many of which will undoubtedly use Atmel microcontrollers (MCUs) to power their respective platforms.

Atmel will proudly be attending Maker Faire Shenzhen this year on April 6-7. Our booth – #4 – is located right next to Center Stage. We’ll be showcasing a number of Atmel-powered products including a Zigebee-based lighting demo, robotic model car, various Seeeduino boards, the Rainbow Cube (LED light controlled by Atmel MCUs) and an e-ink badge.

I’ll also be giving a presentation about Atmel microcontrollers, the IoT and Makers at 2PM on April 7th at the Center Stage. Hope to see you there!

Atmel celebrates International Arduino Day

Today we celebrate Arduino Day and mark the first successful decade of the Atmel-powered boards.

It’s a 24 hour celebration – both official and independent – with Makers all over the world meeting up to share their DIY experiences.

As we’ve previously discussed on Bits & Pieces, Atmel is at the very heart of most Arduino boards on the market today.

Indeed, as 
Atmel MCU Applications Manager Bob Martin recently pointed out, Atmel’s 8- and 32-bit microcontrollers have been the MCUs of choice for Arduino since the boards first hit the streets for DIY Makers way back in 2005. More specifically, he attributes the success of Arduino to its easy-to-use, free cross-platform toolchain and its simple do-it-yourself packages with Atmel MCUs.

“These factors helped initially steer the Arduino team to choose our AVR microcontrollers – and today, both our AVR and ARM-based MCUs,” Martin explained.

In addition to the DIY Maker Movement, the boards are popular with veteran designers, architects and engineers.

“It’s very easy to try out design by building a prototype so that they can see what solutions work and toss out those that don’t. This is much easier to do early in the design process before more money has been spent on bringing an idea to fruition; Arduino can play a key role here,” Brock Craft, author of “Arduino Projects for Dummies,” told ItProPortal in late 2013.

“Just a simple example – I know a lighting company that recently used Arduino to control dimmable lighting effects for architectural lighting products they were developing. Using an Arduino helped them try out their ideas in an afternoon, rather than waiting weeks.”

Arduino boards are also extensively used in the educational community, with science and computing teachers in secondary schools choosing the versatile platform to teach kids the principles of programming and computational thinking.

“[Of course], Arduino is used in colleges and universities, [where] they are often found in design programs, particularly in product design, because Arduinos can quickly be used to prototype products that do physical things – like toasters or dispensers or remote controls, for example,” said Craft.

“It is also widely used in digital arts programs for making interactive artwork, music and performances. [Yes], there have been similar products on the market for many years and education curricula have used other alternatives. But what makes Arduino different – and is driving teachers to use them – is that Arduinos are easy to use. And if they need help, it’s easy for teachers and students to get it in the extensive online communities.”

As Arduino co-founder Massimo Banzi notes, communities are the primary drivers for contribution in the Maker community.

“What you find is that if you can create a community around an open source project then it becomes really alive because everyone starts to contribute. If you don’t have an ecosystem, the platform won’t be successful. If you start charging for everything, everything dies very quickly,” he said.

“There are millions of sandwich places around the world, the recipe for sandwiches is open. Nobody can patent the recipe for a BLTs but yet there’s like a million restaurants doing BLTs. Everyday each one of them is adding a little source, each one is improving the recipe with technique, but effectively what goes inside the sandwich is out there and open and people still make money.”

As Bazni points out, open source hardware like the Arduino helps encourage creativity.

“I think it enables people to share the efforts that are needed to get the certain type of product or project started. Each person adds what some people call the secret source. You can take open source knowledge and add your own secret source,” he added.

“Or you can sell it or sell services around that product. [Arduino] wants to create a platform that’s going to take this and multiply the efficiency, [while] multiplying the value that people get by being part of that community… The challenge is to build a platform that solves a simple problem for a specific group of people: beginners for example. Our boards enable people to get ideas into products very fast. It’s people over Megahertz.”

 

Arduino in a cardboard box

If you went to Maker Faire New York, you saw Atmel’s tables had flashing LEDs on the edge.

The tables Atmel had at NY Maker Faire had LED strips built into them.

Those strips were powered by these custom “Arduinos in a box.” The cardboard box was perfectly in keeping with cardboard tables, made by chairigami.

We created a battery-powered Arduino to run the LED lights on the cardboard tables.

Inside the box is an Atmel-powered Arduino, as well as the battery pack used to run the board and LED strip.

This side has the D-sub connector used to connect to the LED strips. There is also a power connector if you don’t want to run on the internal batteries.

The boxes have a cut-out for the USB connector, should you need to do some emergency programming on the show floor.

A nice touch is the Velcro strip on the back of the battery pack that holds it to the side of the box. You can see the “ECO” (engineering change order) where the USB hole was on the same side, but that got changed in the prototyping stage. Every product tells a story.

Be sure to check out the Atmel booth at Maker Faire Bay Area (Silicon Valley), World Maker New York (in Queens), and in just a few weeks (April 6-7, 2014) we will be at Maker Faire @ Shenzhen (China).

Wayne Yamaguchi talks home-made PCBs

My buddy Wayne Yamaguchi sent a little update on making printed circuit boards (PCBs) at home. Wayne always was the expert on toner transfer PCBs. This is where you print your Gerber art on a special film. Then you use an iron or a hot roller to transfer the printer toner from the plastic film to the copper-clad PCB material. The printer toner becomes the resist that keeps the acid away from the copper foil. Wayne has also figured out how to use a sponge to rub the ferric chloride on the board, so the copper etches away in seconds, not minutes.

I gave this a brief mention in an article about prototyping years ago. Wayne just keeps on improving this process and I hope to give a complete update soon. Wayne is also the guy that figured out PCB-Pool in Ireland was doing good work, as well as the USA triumvirate, Proto Express in Silicon Valley, Advanced Circuits in Colorado, and Sunstone (PCB123) in Oregon. Lately Wayne has been a fan of OSH Park up in Oregon. They operate like a community, where they take a bunch of PCB orders and panalize them on one substrate, so you can share the cost with a bunch of other people. For Wayne’s small boards, this can be ideal.

Wayne Yamaguchi holding a PCB he had made by OSH Park. Before stage this he makes his prototypes with toner transfer and acid etch.

So here is Wayne’s latest missive:

“Many of you know I still make my own PCBs at home. I think I just tweaked or ironed out a nagging issue. Sometimes I would lose some toner during the process of putting it on the PCB. Using the GBC laminator I’ve had reasonable success and I finally think that putting the board through once is insufficient to apply pressure across the whole board. I put the board in offset 30 degrees and then a second pass with the board turned offset -30 degrees. Putting the board through the laminator at different angles ensures all of the board gets heated and pressed.

“Here’s a board I made a week ago and now it’s aged and somewhat tarnished. You can see the test patterns in the circuit and one test pattern outside of the circuit board. All test patterns came out. The test pattern has an 8 mil trace, 6 mil trace, 4 mil trace and a 2 mil trace. Of course they all get flattened out during the process, but, the 2mil really had little toner and was surprised how well it came out even if it was flattened.

Wayne Yamaguchi gets down to 2-mil traces with home-made PCBs done with toner transfer and ferric chloride acid etch.

“Rough measurements show the 2mil came out around 3mil and the 4 mil squished out to around 5.5mil and the 8 came out around 11 mil. Typically for prototypes I try and stay with 10mil trace widths.

“This particular prototype yielded some good info and with that info I’ve made a few changes and have sent out for real 2 sided PCB at OSHPark. The OSHPark order came out to a total $4.95. The boards were placed on a panel within a day or so and have been sent out to the fab shop. I might get the boards next week some time.

“The process is a slight derivation from Pulsar, who created this process a long time ago.  Frank at Pulsar is the originator and should get all the credit for the process.”

Well thanks Wayne, many of us still like to whip out a single-piece prototype before going to fab and this is a great way to do it. My only warning, gleaned from personal experience, is to not put any vias under surface mount parts. There are no plated-through holes with these home-made PCBs, so you have to solder a little wire into every via.

Going back to school with Arduino

Jim Town, a math teacher at West Sacramento Prep, began incorporating Arduino boards in his math lessons last year. He soon found that the Atmel-powered hardware helped facilitate a “different type” of learning with high levels of engagement.

“Pre-calculus is a class that has many opportunities for creative teaching. Since we are a smaller school, there isn’t enough interest in computer science to justify a full class so I try to embed some of these skills into my math classes to help students become ready for the computer heavy careers that may await them,” Town explained in a recent blog post published in Makezine. “One way I’ve found to do this is through Arduino. My students had heard of Arduino because we had a few students working on Arduino projects last year, but had never worked with them. They were excited at the opportunity to ‘play’ in math.”

In the above-mentioned project, students learned about exponents and counting in binary, but probably did not learn the rules for simplifying exponents or other ultra-specific standards. However, Town says he views math more as a way of thinking, rather than a specific set of skills.

“In conjunction with the unit on exponents, I challenged students to make a binary counter using either a dip switch or a momentary switch. A dip switch is a row of on/off switches conveniently labeled 1-8; they are like a bunch of little tiny light switches,” said Town. “For these students, when the switch labeled 6 was turned on, they needed to display a 6 in binary on the three LED’s they were given (on-on-off). A momentary switch is a single button that is ‘on’ when pushed and is ‘off’ when not pushed. The students had to keep track of how many times the button was pushed and display that number in binary on the LED’s. That is, if they button was pushed 4 times, the three LED’s would show on-off-off.”

In addition to the DIY Maker Movement, Arduino boards are wildly popular in the educational community, with science and computing teachers in secondary schools using the versatile platform to teach kids the principles of programming and computational thinking.

According to Brock Craft, author of Arduino Projects for Dummies, the Atmel-powered boards are also used in colleges and universities, where they are often found in design programs, particularly in product design.

“[This is] because Arduinos can quickly be used to prototype products that do physical things – like toasters or dispensers or remote controls, for example. It is also widely used in digital arts programs for making interactive artwork, music, and performances,” Craft told ItProPortal. “[Yes], there have been similar products on the market for many years and education curricula have used other alternatives. But what makes Arduino different – and is driving teachers to use them – is that Arduinos are easy to use. And if they need help, it’s easy for teachers and students to get it in the extensive online communities.”

In addition, Craft confirmed that Arduino boards are deployed throughout the corporate world, as the hardware is being used by designers, architects and engineers for prototyping purposes.

“It’s very easy to try out design by building a prototype so that they can see what solutions work and toss out those that don’t. This is much easier to do early in the design process before more money has been spent on bringing an idea to fruition; Arduino can play a key role here,” he added.