EELive! Conference a big splash in Silicon Valley

I went to the EELive! Conference in San Jose last week and it was a blast. This is the new incarnation of the old Embedded Systems Conference (ESC). Last year it was branded Design West, but I suspect that was too generic, since it is not aimed at mechanical engineers that might read Design News. Another problem with the word “design” is that in the semiconductor industry, only IC engineers are considered “designers.”

I was delighted to hear that UBM, the folks that run the show are considering moving it to Santa Clara convention center next year. I like Santa Clara better since the parking is free, it’s easier to get to, and its right near my house.

So following are some snaps I took on the show floor. Bear in mind that another big part of the EELive! is the conference part, where you can learn about the latest secrets and tips and tricks from technical experts. You have to pay for the conference, but they were nice enough to give a single-class pass to regular shmucks like me that were just attending the free show on the exhibit hall.

As you entered the show floor there was this great theater (or should I say theatre) set up. Here we see show runner Karen Field and EETimes editor Max Maxfield doing a fun give-away. I ran into Max later that evening and he gave me his business card, which lists his title as “Editor of all things fun and interesting.”

There was always a healthy crowd at the theatre, and they were always having a good time. It’s really great to see this combination of social and technology at technical conferences.

If you work with RF, you know that Rohde & Schwarz makes some of the best test equipment on the planet. They are best known for their spectrum analyzers, but now they are making oscilloscopes and hand-held instruments.

Where Rohde & Schwarz really stands out in my mind is network analyzers like this baby. They have some of the lowest-noise units in existence. A network analyzer is like a spectrum analyzer that also measures the phase change of a signal. So rather than just read the spectrum, the unit sends out a signal you connect to your circuit, and then you can get a gain-phase plot, or in this case, you can see a Smith Chart displayed right on the screen. Note the frequency range for this instrument—9 kHz to 6 GHz. That is 9,000 to 6,000,000,000, or nearly 6 decades of range. That is quite an accomplishment. Those N-type connectors on the front belie what a fast beast this is. BNC connectors are not suitable for multi GHz frequencies.

Here is Rhode & Schwarz account manager Steve McMoyler in front of a display of a bunch of cool test equipment he sells. I complained that Rohde & Schwarz stuff is so good we can never find a cheap deal on eBay. He laughed, and pointed out a lot of their new stuff is really cost competitive. I put this to outfits like Rigol selling 400-dollar scopes that, while not the greatest, will actually trigger and show you a waveform. These cheap scopes have put pressure on all the test equipment manufacturers. Then again, the Maker movement has increased the market for these inexpensive products, so the manufacturers can archive high-volume cost efficiencies.

National Instruments had a great booth at EELive! this year. This pic was as the show opened on Thursday, but before long, the booth was swamped with engineers interested in everything from Labview visual programming to the MultiSim Spice simulation program so loved by colleges around the world.

Element14 was at the show, the folks previously know as Newark Electronics. Everything from game controllers to motor control was on display.

One nice feature of EELive! are these little classes put on in glass booths throughout the show floor. You can see this one was packed, standing room only. There is a real hunger to learn the expertise to design and program embedded systems.

The Segger folks were there. Atmel uses Segger debugging technology in a lot of their eval boards. Here we see James Murphy and Shane Titus ready to answer any questions.

Here is the Atmel SAMA5D3 evaluation board with Seggar technology running their emWin graphics library.

The PCB fab companies were there, including the PCB-POOL folks my buddy Wayne Yamaguichi liked so much.

Here we see Tony Shoot from PCB-POOL showing some of their capabilities, as they segue into a full prototype shop.

The LeCroy folks were at the show. I can’t get over how beautiful the display is on these modern scopes. I bought one of their $60k units when I was at National Semiconductor. The engineers used to Tek or Agilent would complain the user interface was weird, but once they bothered to learn it, you could not tear the LeCroy scope out of their hands. I myself have a LeCroy 9360 digital scope at my home lab.

Here is a LeCroy serial data analyzer on the left and a HDO4000 scope on the right. Its got a 4k screen and 12-bit resolution. Those big 12-inch screens sure can spoil you. Note they have a web-cam perched on top of the scope with a real-time video displayed on the top right of the screen. They are piping the scope screen to the TV, talk about reducing eye strain when you debug. Sweet.

The Screaming Circuits folks had a booth. These are the people that will assemble small quantities of your circuit boards. They have special machinery so they don’t need 3 feet of tape and real parts for any build. You can send them your Digi-Key cut-tape parts and they can feed them into their tape and reel machines. That way you can check out your insert file and assembly drawing and have circuit boards made in a real IR reflow oven. Here Scott Pohlmann was ready to answer any questions about protying and their partnering with Sunstone and other fab houses, as well as Digi-Key. They can even have your designed kitted up, get the boards fabbed at Sunstone and delivery you assembled boards.

Atmel had their giant Tech on Tour trailer at right on the show floor. Michelle would buzz you in to checkout all the demos and give access to Atmel applications people that could answer your questions or help with your next project.

One demo that people loved was the MakerBot, which would make items like this while you watched.

Here is a little movie of the Makerbot in action. It is hypnotizing to watch.

Biosensors you stick to your skin

CBS ran an interesting article about tiny biosensor patches that monitor your health while they are stuck to your arm or leg. The article referenced work done by engineers at the University of Illinois at Urbana-Champaign and Northwestern University. You stick the biosensor to your skin like a temporary tattoo. The work was presented in a paper hidden behind a paywall at Sciencemag.org. The abstract reads:

“When mounted on the skin, modern sensors, circuits, radios, and power supply systems have the potential to provide clinical-quality health monitoring capabilities for continuous use, beyond the confines of traditional hospital or laboratory facilities. The most well-developed component technologies are, however, broadly available only in hard, planar formats. As a result, existing options in system design are unable to effectively accommodate integration with the soft, textured, curvilinear, and time-dynamic surfaces of the skin. Here, we describe experimental and theoretical approaches for using ideas in soft microfluidics, structured adhesive surfaces, and controlled mechanical buckling to achieve ultralow modulus, highly stretchable systems that incorporate assemblies of high-modulus, rigid, state-of-the-art functional elements. The outcome is a thin, conformable device technology that can softly laminate onto the surface of the skin to enable advanced, multifunctional operation for physiological monitoring in a wireless mode.”

This biosensor can monitor your health when adhered to your body.

What was telling about the paper were all the people involved:

Sheng Xu, Yihui Zhang, Lin Jia, Kyle E. Mathewson, Kyung-In Jang, Jeonghyun Kim, Haoran Fu, Xian Huang, Pranav Chava, Renhan Wang, Sanat Bhole, Lizhe Wang, Yoon Joo Na, Yue Guan, Matthew Flavin, Zheshen Han, Yonggang Huang, and MacArthur fellow John A. Rogers.

I am not sure if that is a list of grad student slaves or distinguished professors, but the CBS article neglected to mention that some of the authors represent Tsinghua University in Beijing, Zhejiang University in Hangzhou, and Hanyang University in Seoul. This long list confirms the observation of my pal Ed Fong that system-level design requires engineers that are more social than IC designers and, I suspect, programmers. Ed has done both IC design and worked in complex electro-mechanical systems, so he should know. When you do a complex system like these biosensors it only stands to reason you would need a lot of people involved since there is so much expertise needed in so many areas.

The flexible sensor is like a temporary tattoo, it can bend and flex with your body in order to stay attached and keep working.

Here is a closeup.

And an ultra-close-up.

The new paper implements a complete system based on these biosensors. Adding a power system and a microcontroller and probably a radio is not trivial, hence the large crown of contributors. Another thing that makes me proud of the recent paper is that it has contributors from the US, China, and Korea. That is what I love about technology and engineering. While other industries and politicians give lip service to diversity, the tech industry has practiced it for decades. Here in Silicon Valley every tech company is more like the United Nations. As long as you know what you are doing, you can work anywhere you want, and that is something we all should be proud of.

Here is a biosensor as it would appear adhered to a heart.

Speaking of medical devices, my pal Ken Carroll went to work for Nanostim over 5 years ago. The idea is to make a heart pacemaker so small that you can just attach it to the heart. The wires of a pacemaker are one of the most problematic components, and they wear out and need replacement before the pacemaker battery dies.

This Nanostim pacemaker is 1/10 the size of a conventional one. It is implanted directly in the heart, needing no fragile wires to deliver the pulses to the heart.

Here is the Nanostim pacemaker in-situ.

Ken is a great IC designer, and if anyone can make a chip small enough and low-power enough, he can. I see Nanostim was acquired by St Jude’s Medical last year, so that is good news for all the people that worked for so many years to make this a reality. I have a mechanical engineer buddy that works at a laser eye surgery place, and he tells me it is really exacting work when you have to keep the FDA happy.

Atmel’s SAM4L at the Colorado School of Mines

Analog aficionado and Linear Systems marketing maven Tim McCune saw some of our cool ARM Cortex M4-based SAM4L-EK demo kits at the last Analog Aficionados party. Turns out his son Clark just entered the Colorado School of Mines and Tim thought his son could learn a lot from the kit. This is the same kit that Atmel is featuring in its 2014 Tech on Tour training, where we drive a giant 18-wheeler truck onto your campus or company and then do training or product demos.

The Atmel Tech on Tour mobile trailer is available to drive to your location and conduct training for employees or students.

So I wangle a couple kits from Atmel events director Donna Castillo and sent them off to Clark. In addition to the ARM Cortex M4-based SAM4-EK, the training bundle had an AT86RF233 Xplained Pro wireless board and an 10-pin XPRO adapter PCB. This allows the SAM4 Xplained pro to take the RF board.

Tim reported the kits were a big hit:

“The kits arrived last Friday, before the three-day weekend, which was a great morale-booster for Clark. He was stuck there with not much to do, most of his friends were at home or skiing. Figuring out how to fire up the kits and start working in C was pretty fun. And when his classmates started drifting back he had the coolest new toys on the hall.”

Clark McCune and pal fires up the Atmel SAM4-EK at the Colorado School of Mines.

 

Here Clark McCune has both SAM4-EK kits at the ready, with the one hooked to the computer also sporting the AT86RF233 wireless board that comes with the Tech on Tour training.

Here are the kits I sent Clark McCune. The Tech on Tour training will get you up to speed on ARM Cortex M4 programming as well as wireless connectivity.

The SAM4L-EK has a board and a ton of cables including the micro-USB ones you will need to power the board.

Both displays have a protective film over them, so be sure to peel them off to get the best appearance.

Right out of the box the board is programmed to read the slider on the bottom right side. The number “104” changes in proportion to your finger posing. Note the smaller power consumption display above the main one. The L in SAM4L stands for low power, so Atmel includes a power monitor right on the board.

We also include the jumpers, just set off to the side, so you don’t have to hunt any down from your old Windows 95 add-in cards.

Here is the SAM4L set up with the AT86RF233 Xplained Pro wireless board and an 10-pin XPRO adapter PCB. I hope Clark had them in the right way because I just copied what he had in his picture.

Here is a close-up of the power monitor display. With the programs running full-bore, you can see the board is using 1.92 mA, but the firmware is nice enough to tell you it is using 159μA/MHz.

Press pushbutton PB0 and the board kicks into standby, where the PCB only draws 66μA. Sorry for the shaky camera, the display is sharp as a tack.

Speaking of shaky camera work, I tried to press the PB0 pushbutton and snap a pic at the same time, so you can see the little display on the SAM4L-EL work like a tiny oscilloscope, showing the power consumption dropping from 2mA to 69μA.

And finally, another shaky camera shot of the SAM4L-EK returning to full power mode.

What is really cool about the little power monitor is that it does show transient events, like when the code services an interrupt and returns to low-power mode. Oh, I forgot to show the back of the PCB, here is a shot:

The back of the SAM4L-EK has more chips, I assume to run the debugger and such. Note the nice clear rubber feet to keep the pins from scratching your desk.

This is such a well-done kit, and if you want to get on the ARM bandwagon, it is a perfect way to learn. Better yet, with the RF board it gets you familiar with the Internet of Things (IoT) applications the whole world is hungering for. So check out the Tech on Tour training and feel free to badger you local Atmel rep or FAE to bring the ToT mobile trailer to your school or company.

Time-lapse photography trigger on an Arduino Shield

A Shield is a plug-in mezzanine board that fits into Arduinos. I was looking for a remote trigger for my great Panasonic GH3 camera I use for some shots in my Atmel Edge web show. So I was delighted to run across this little time lapse trigger Arduino Shield that visual effects artist Dan Thompson is working on.

This is the circuit board layout for Dan Thompson’s time-lapse Arduino Shield.

That lucky happenstance led me to other Arduino-based time-lapse controllers like this one from “hacker3455”.

This is another Arduino-based time-lapse shutter controller.

 

And here is a yet another time-lapse Arduino on Hack-a-Day.

 

And if you want to get that “Bullet time” look like in the Matrix
movies, there is even an Arduino-based time-lapse dolly controller.

 

There are several controllers, like this one you can to pans and tilts with. Here is a little test video of the prototype:

Of course, the path software is critical and the community does not disappoint, with code like this, developed by Airic Lenz, the fellow that did the above video.

This is the kind of tech that South Dakota farmer Randy Halverson stunned the world with back in 2013. Here is a vid with the man himself:

Here is a video of an Arduino-based dolly in action:

And here is one more time-lapse controller from the wonderful folks at Practical Arduino.

The new Atmel-ICE debugger is here

I ordered the new Atmel ICE debugger as soon as it appeared on the company store. I see there is still stock so feel free to put in an order with us or your favorite distributor. Don’t get this new one confused with our JTAGICE3,  sometimes called JTAGICE markIII or mk3. It looks similar, but this new one has two debugging connectors. One is for the AVR microcontrollers, and one is for ARM MCU devices. There is a nice slide-show and explanation on our Norway site.

The new Atmel-ICE is white and has two connectors for debugging. The old JTAGICE3 (inset) is silver and only has one connector, although you can upgrade the firmware so it can debug SAM D20 ARM-based MCUs.

Best yet, just like we lowered the priced between the JTAGICE2 and JTAGICE3, we lowered it again for the Atmel ICE. You can get the fancy high-zoot version for 85 bucks. It has the pretty box and all the cables. Then there is a stripper version with just one debug cable for $49. Finally, you can get a bare-board version with no case or cables for a measly $32. This is a great deal when you think that a JTAGICE2 was $399.

This new Atmel-ICE replaces both the Dragon and the JTAGICE3. The only other ARV debugger you might need is the AVRONE! debugger that has trace capability. It’s 600 bucks, but that is worth every penny if you are trying to figure out where your program went or how it entered a subroutine or interrupt vector.

For the “big iron” ARM MPU (microprocessor units) with external memory you can use the SAM ICE. The SAM-ICE is in our store for 100 dollars. This works with Atmel’s MPU chips like the ARM Cortex A5-based chips like the SAMA5D series, and the ARM9-based SAM9x parts.

I unboxed my new Atmel-ICE today, here are the pictures:

The box has a Norse warrior on it, as tribute to the brilliant Norwegian engineers that invented the AVR chip.

Open the box and you see the Atmel-ICE on the left, safely snuggles in anti-static foam, and a box on the right with the three cables and breakout PCB.

Here is a close-up of the debug connectors. Identical, but the one on the right is for AVR and the one on the left is for ARM-based MCUs.

The Atmel ICE uses the micro USB connector. The two more expensive versions come with the cable, the bare PCB does not.

To keep costs down we didn’t paint the logo on, you can see it is nicely inset, as are the “AVR” and “SAM” indicators to tell you which debug connector is which. Check out how nice and small the unit is. This is another improvement over the JTAGICE2, and a real benefit on a crowded desk or lab bench.

Here is the cables that come in the 85-dollar unit. You also get the USB cable. Note the one cable comes with that cool breakout board.

The breakout board has a silkscreen on both sides to help you figure out what it plugs into.

Using Arduino PWM for constant-current drive

The always excellent Circuit Cellar Magazine has a nice article by Ed Nisley. Arduino PWM vs MOSFET Transconductance describes his characterization of Arduino PWM outputs for the constant-current drive of MOSFETs. His application is LED drive, but you could use the knowledge anywhere, including a programmable current sink. Now Circuit Cellar is a paid-subscription magazine, so I can’t link to free article, but maybe their lawyers will let me take a picture of a picture in the print magazine, to which I am a long-time subscriber.

This photo of the board Ed Nisley used to develop his constant-current source tells you it is not some Spice simulation or a theoretical track. This is a sure tip-off that Ed knows what he is writing about.

This scope shot also reassures you that Ed is not venturing forth some opinion on how the hardware and firmware works, it is proof positive he built this stuff and that it really works. I scratched off the readouts to make sure this is fair use and not a violation of Circuit Cellar’s copyrights.

Analog Guru Paul Grohe taught me that you should always look for pictures of real hardware in articles, and that if the curves are ”too pretty” they are probably marketing BS instead of real data. That is the great thing about this article; it’s got both pictures and data that tell you that you can trust the content.

There is another interesting article in the March 2014 Circuit Cellar issue. It’s about an outfit called ImageCraft. They make a C compiler with an IDE (integrated development environment) for Atmel AVR and ARM Cortex-based MCUs. Now I am a fan of Atmel’s free Studio 6 IDE, but feel free to use whatever IDE you prefer to write the code for your projects.

Now I can’t show you these articles on-line, since Circuit Cellar is a subscription print magazine. You have to give them 50 bucks a year to get it. You can get it as a digital pdf if you want to save trees. Its $85 a year for the both print and digital versions. There are large discounts for two- or three-year subscriptions. Best of all, you can give them something like $225 and get every single issue in history on a thumb drive. Then with your combo subscription you can add your monthly pdf to the archive thumb drive, and still have the print edition to impress your friends and boss.

SAMA5 and SAM9: Atmel’s big iron microprocessors

Atmel is rightly famous for its AVR line of 8-bit Flash microcontrollers. But we also have “big iron” chips like the SAMA5 and SAM9 ARM-core microprocessors. A microcontroller has its own internal Flash memory. A microprocessor uses external memory, as much or as little as your application might need.

Hardware engineers have two big worries with any “big iron” microprocessor. First, they are in big packages, hundreds of pins in a ball-grid array. That can be hard to prototype with, since it needs a fine-line PCB that costs a lot to spin. The other big concern is laying out the DDR memory interface. These are wickedly fast and require best layout practices and some register tweaking to get them up to full speed.

The SAMA5D3 Xplained kit has connectors for Arduino Shields and dual Ethernet ports.

Thankfully, Atmel has solved both problems with a series of evaluation systems. For the SAMA5, you can start with a 79-dollar SAMA5D3 Xplained Kit. It has solved your DDR memory problem since it’s got 256MB on-board. One of the coolest things is that it has connectors where you can plug in any Arduino Shield. Now you can’t use the Arduino libraries, those are based on Atmel’s 8-bit AVR, but it’s not hard to re-write the open source code libraries into something that will run on ARM, if someone hasn’t done it already. The eval board has Atmel’s SAMA5D36 Cortex-A5 Microprocessor, 256Mbytes of NAND Flash, LCD connectors, dual Ethernet (GMAC + EMAC) with PHY and connectors, three USB connectors (2 Host + 1 Device), one SD/eMMC and one MicroSD slots, expansions headers, and power measurement straps.

Atmel makes eval kits for the SAM9N12 (left) and SAM5D3x ARM-based microprocessors.

For those that are doing higher-level applications, the fact that you can run Linux brings all the advantages of open-source development to the SAMA5 and SAM9 microprocessors. And best yet, you get a powerful CPU that uses very little power thanks to Atmel’s architecture. The SAMA5 uses 150mW when running at full speed. It has a DDR controller that give you 1328MB/s of bandwidth. It comes with for gigabit Ethernet, 3 USB ports, dual CAN, UARTs, SPI, and an LCD controller with a graphics accelerator. There is a camera interface, a 12-bit analog to digital converter (ADC) and 32-bit timers.

A SAMA5 chip can run Linux and even has the power to run Android in a “headless” application, that is, where there is not a high-resolution display to eat up your CPU cycles. With an ARM core it’s ideal if you want to do “bare metal” development, where you are writing native ARM code.

The SAM9N12 architecture gives you low power and a great peripheral set.

Looking at the SAM9, the SAM9CN runs at 400MHz. They have security built in with a cryptographic engine and a secure boot. There is an LCD controller with touchscreen interface, USB, MLC NAND memory support, along with multiple UARTs and I²C. It sips 103mW at 400MHz.

You can get separate LCD panels made to work with the SAMA5 Xplained kit. But if you want to get a SAMA5 kit with the LCD already included, look at the 595-dollar SAMA5D31, SAMA5D33, SAMA5D34 and SAMA5D36 kits. There is also the 445-dollar SAMA5D35 kit, which is cheaper since it does not have an LCD system. These kits cost more but they come ready to go. These are a small working computer that you can immediately start programming in high-level languages or Linux scripts. The kits come with installed applications for its Qt-based GUI.

The SAM5A5Dx-EK demo kit comes with Linux and some demo applications pre-installed.

And if you dread laying out a PCB with a working DDR memory interface, but don’t need the whole $595 kit, you can get help there as well. You will notice that the microprocessor and memory are on a little mezzanine PCB in the SAMA5D3 demo kits. This PCB will be available from Embest and other partners. The SAM9 is also available as a tiny SBC (single-board computer).

The SAMA5D3-EK series are designed with a mezzanine card holding the CPU and DDR memory. You can use this card in your high-volume designs.

So now you can develop your custom hardware starting with the SAMA5D3 kit, and then make your own custom hardware that still uses the same exact CPU+memory mezzanine card. While you are perfecting and troubleshooting that hardware, your software team can be working on the Atmel eval kit. This paralleled development will substantially speed up your time to market. And best yet, you won’t be bogged down trying to troubleshoot the DDR memory interface, since it is already working on the mezzanine card.

So don’t just think of 8-bit AVRs when you consider Atmel. We make some really high-power MPU products for everything from IoT (Internet of Things) servers to routers and industrial automation. With Atmel’s kits and our extensive partner network, we can get you up and running in no time, for very little cost, and you can have confidence you designs will work on that final hardware spin.

Passing CE immunity testing

When I was working on semiconductor machinery, we used TUV to get CE certification so we could sell the machines in Europe. We got through emissions alright, it’s similar to the FCC testing we already did, but immunity testing was brutal. When we broadcast RF at a machine, the wafer elevators went nuts and started breaking wafers. We had managed to convince the TUV guy that the speckles and snow on the monitor were not technically a failure, since you could still read it. But robots going open-loop? No, nobody could talk that past TUV. Turns out the cabling was the culprit. There was shielded twisted pair to the Banner sensors that located the elevator stops. In fact, I think they even used braid+foil shielded wire. But the semiconductor machinery company connected the cables with those red-brick AMP connectors, the MR series.

MR These MR (miniature rectangular) connectors work great for appliance wiring, but they provide no continuous shielded path for radio frequency interference (RFI).

Now designing cabling is often thought of as a mechanical engineering function. But mechanical engineers often don’t understand the principles of RF shielding. Get this— they cut the cable shielding about 2 inches back, connected the power, ground, and signal to pins, and yeah, they connected the braid to a pin, and sent it into the connector, to mate with another cable that had 2 inches pulled back. The cables were all dressed beautifully and shrink tubing everywhere. But like my buddy says—“4 inches of untwisted unshielded wire is a nice antenna.”

D-sub The D-sub connector was developed for military applications and then picked up by PC makers for serial, parallel and video ports. One reason is its good RF performance. Make sure your cable braid contacts the metal shell.

I switched them to D-subs using 9 pins with a metal shell, and we finally passed. So remember, RF energy is like light—it can leak into the smallest spaces and screw things up. Make sure the EE department revises the detailed design of the cable, or your machine might get held up in certification too.

Crushed avionics from a 737 nose wheel collapse

I have several pals that work on airplane avionics. Talking to one last week, he mentioned that he has a picture of what happens to the high-dollar avionics bay of a 737NG when the nose wheel folds back and collapses on landing.

Ouch. This 737NG avionics bag got pretty well crushed when the nose gear folded up on landing.

Be glad your electronics was not in this mess. I guess this is a case of just taking out the whole rack and putting in a new one. It was nice that the collapsing electronics sort of cushioned the blow, and protected the airframe from a high-g impact.

My pal Jerry Alvarado (RIP) worked as a machinist for United up in San Francisco airport. He told me that they were constantly rebuilding nose gears, as the load when the plane drops onto it is pretty severe. I asked if they pushed him to rush out a job, and he said “No way, I can take as long as I need. Hey, our mothers ride on airplanes too.”

That was certainly comforting in this day of cutting corners and slapping things together.

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.