Brain Control: An Interview with Dr. Max Ortiz Catalan

Dr. Max Ortiz Catalan is Research Director at Integrum AB, a medical device company based in Molndal, Sweden. Wisse Hettinga recently interviewed him about his work in the field of prosthetic design and biomedical systems.MOC_Lab3

As an electrical engineer, your first focus is to create new technology or to bring a new schematic design come to life. Dr. Max Ortiz Catalan is taking this concept much further. His research and work is enabling people to really start a new life!

People without an upper limb often find it difficult to manage tasks due to the limitations of prostheses. Dr. Catalan’s research at Chalmers University of Technology and Sahlgrenska University Hospital in Gothenburg, Sweden, focuses on the use of osseointegrated implants and a direct electronic connection between the nervous system and a prosthetic hand. People can control the prosthesis just like you control your hand, and they are able to sense forces as well. The results are impressive. The first patient received his implant three years ago and is successfully using it today. And more patients will be treated this year. I recently interviewed Dr. Catalan about his work. I trust this interview will inspire seasoned and novice engineers alike.—Wisse Hettinga

HETTINGA: What led you to this field of research?

CATALAN: I was always interested in working on robotics and the medical field. After my bachelor’s in electronics, my first job was in the manufacturing industry, but I soon realized that I was more interested in research and the development of technology. So I left that job to go back to school and do a master’s in Complex Adaptive System. I also took some additional courses in biomedical engineering and then continued working in this field where I did my doctoral work.

HETTINGA: I was surprised you did not mention the word “robot” once in your TEDx presentation (“Bionic Limbs Integrated to Bone, Nerves, and Muscles”)? Was that coincidence or on purpose?

CATALAN: That was coincidence, you can call a prosthesis a “robotic device” or “robotic prosthesis.” When you talk about a “robot,” you often see it as an independent entity. In this case, the robotic arm is fully controlled by the human so it makes more sense to talk about bionics or biomechatronics.

HETTINGA: What will be the next field of research for you?

CATALAN: The next step for us is the restoration of the sense of touch and proprioception via direct nerve stimulation, or “neurostimulation.” We have developed an embedded control system for running all the signal processing and machine learning algorithms, but it also contains a neurostimulation unit that we use to elicit sensations in the patient that are perceived as arising from the missing limb. The patients will start using this system in their daily life this year.

HETTINGA: You are connecting the controls of the prosthesis with nerves. How do you connect a wire to a nerve?

CATALAN: There are a variety of neural interfaces (or electrodes) which can be used to connect with the nerves. The most invasive and selective neural interfaces suffer from long-term instability. In our case we decided to go for a cuff electrode, which is considered as a extra-neural interface since it does not penetrate the blood-nerve barrier and is well tolerated by the body for long periods of time, while also remaining functional.

HETTINGA: Can you explain how the nerve signals are transferred into processable electric signals?

CATALAN: Electricity travels within the body in the form of ions and the variations in electric potentials, or motor action potentials for control purposes. They are transduced into electrons by the electrodes so the signals can be finally amplified by analog electronics and then decoded on the digital side to reproduce motor volition by the prosthesis.

HETTINGA: What is the signal strength?

CATALAN: Nerve signals (ENG) are in the order of microvolts and muscle signals (EMG) in the order of millivolts.

HETTINGA: What technologies are you using to cancel out signal noise?

CATALAN: We use low-noise precision amplifiers and active filtering for the initial signal conditioning, then we can use adaptive filters implemented in software if necessary.

HETTINGA: How do you protect the signals being disturbed by external sources or EM signals?

CATALAN: Since we are using implanted electrodes, we use the body as a shielding, as well as the titanium implant and the electronics housing. This shielding becomes part of the amplifier’s reference so it is rejected as common noise.

HETTINGA: How are the signals transferred from the nerves to the prosthesis?

CATALAN: The signals from nerves and muscles are transferred via the osseointegrated implant to reach the prosthesis where they are amplified and processed. In a similar ways, signals coming from sensors in the prosthesis are sent into the body to stimulate the neural pathways that used to be connected to the biological sensors in the missing hand. Osseointegration is the key difference between our work and previous approaches.

HETTINGA: What sensors technologies are you using in the prosthetic hand?

CATALAN: At this point it is rather straightforward with strain gauges and FSRs (Force Sensitive Resistor), but on research prostheses, motors are normally instrumented as well so we can infer joint angles.

This interview appears in Circuit Cellar 307 February.

Mitch Altman—Maker, Hacker, Traveler

Mitch Altman is an inventor (TV-B-Gone), hacker and traveler whose ideas will inspire many of us to join a hackerspace and get creative with the design community. Circuit Cellar recently met up with Altman at FabLab Berlin, Germany. Altman talks about hacking and presents a new synthesizer, which is a board with an Arduino, sound amplifier, and keyboard-shaped pads to play music.

21st-Century Electronics Craftsman: Meet Saar Drimer

Saar Drimer (PhD, Cambridge) runs Boldport, a London-based hardware and prototyping consultancy that specializes in circuit boards. Wisse Hettinga recently met with Drimer to discuss PCB design, electronics craftsmanship, and his various engineering projects.

Saar Drimer, electronics craftman

Saar Drimer, electronics craftman

Hettinga writes:

The Art of Electronics is a book that’s well-known by many electronic engineers all over the world. Written by Horowitz and Hill, the first edition was published in 1980 and recently, in 2015, a third edition was released. Over the past 35 years, the book has been an inspiration and resource for many engineers eager to learn about the art of designing with electronics. But there is also a real art of electronics. To discover what that is, I traveled to London to meet up with Saar Drimer. His workplace was in one of the characteristic arches underneath London Bridge Station. With the constant rumble of the trains arriving and pulling out of the station in the background, he showed me some of his work.

Drimer’s designs are completely different from what we usually see on PCBs. Where most of our designs end up as small rectangles with only a few holes for the assembly screws, his boards take different shapes. Some are swirly, sometimes animal-like. At other times, he integrates components right into the board in special holes, as you can see in his Tiny Engineer Superhero Emergency Kit. Often there is no straight copper line to be found; they go all over the place and are a vital part of the total design.

Emergency kit

The Tiny Engineer Superhero Emergency kit

A PCB designed by Drimer asks for exposure and can be interesting for art’s sake only, but also for marketing purposes where drawing attention and presenting a surprise is required. One of his designs even features in the women’s magazine Marie Claire!

Where many of us try to put all the PCB and wiring in a (mostly) gray box and leave it out of sight, Drimer is doing exactly the opposite: he is trying to expose it. His end product is the PCB and that is where his art comes into the picture—in many exciting formats. In many ways, Saar is an engineer like many of us. He is extremely knowledgeable about electronics and designing. But when it comes to the latter, he is using unorthodox methods. Where we start with the schematics, Drimer starts with the form and shape of the final PCB—basically, he designs the other way around!

Working and designing in the opposite direction is not easy with existing PCB CAD programs like Eagle or Altium. They all start with a schematic and are using component libraries routing the final layout in the most effective or smallest footprint PCB. Their rigid, straightforward approach is excellent when designing for just another rectangle PCB. But if you want new and creative designs, you need to think of a different way of working and using other tools. If you want to change the way of thinking and designing, you need to be able to use free forms and the routing cannot be left to the CAD program. And that is exactly what Drimer is doing.

To be able to start with a different type of design, Drimer was left with no choice but to start developing his own PCB CAD design program. Unlike most of us who call ourselves “engineer,” Drimer calls himself ”craftsman”—and as a true craftsmen, he makes his own tools. PCBmodE is Drimer’s custom PCB CAD program. The “mod” in PCBmodE has a double meaning, Drimer explained. “The first is short for ‘modern’ in contrast to tired, old EDA tools. The second is a play on the familiar ‘modifications,’ or ‘mods,’ done to imperfect PCBs. Call it ‘PCB mode’ or ‘PCB mod E’, whichever you prefer,” he said.
PCBmodE is a PCB design Python script that creates an SVG from JSON input files. It then creates Gerber (the standard software to describe the PCB images: copper layers, soldering mask, legend, etc.) and Excellon files for manufacturing. With no graphical interface, PCBmodE enables you to place any arbitrary shape on any layer because it is natively vector-based. Most of the design is done in a text editor with viewing and some editing (routing) completed with Inkscape. (Inkscape is a professional vector graphics editor for Windows, Mac OS X, and Linux. It’s free and open source.) On his website, Drimer explains how to work with the program.

“PCBmodE was originally conceived as a tool that enables the designer to precisely define and position design elements in a text file, and not through a GUI. For practical reasons, PCBmodE does not have a GUI of its own, and uses an unmodified Inkscape for visual representation and some editing that cannot practically be done textually,” said Drimer.

A typical PCBmodE design workflow is as follows:

  • Edit JSON files with a text editor
  • “Compile” the board using PCBmodE
  • View the generated SVG in Inkscape
  • Make modifications in Inkscape
  • Extract changes using PCBmodE
  • Back to step 1 or step 2
  • Generate production files using PCBmodE

If you want to give PCBmodE a try, simply download it at It works with Linux, but Drimer is interested in results on other OS platforms as well. For starters, a “hello solder” design is currently available.

Hello Solder

Starter example: Hello Solder

Examples of Drimer’s work are posted on his website, I especially like the Tiny Engineer Superhero Emergency Kit’ design where the components are integrated into the PCB itself resulting in a very flat design. You will also notice he is not using straight lines and angles for the traces. It is more of a pencil drawing; the traces flow along the lines of the PCB and components.

You might ask why on earth someone would put so much effort into all of this? Don’t ask! But, if you like, here are a few answers. First, because it is an art. Second, it is Drimer’s full-time job and he hopes to expand the business. And third, working differently from the norm tends to generate fresh ideas and exciting solutions—and that is what we need more of.

This article appears in Circuit Cellar 306 (January 2016).

Innovative Product Design: An Interview with Rich Legrand

Rich Legrand founded Charmed Labs in 2002 to develop and sell innovative robotics-related designs, including the Xport Robot Kit, the Qwerk robot controller, the GigaPan robotic camera mount, and the Pixy vision sensor. He recently told us about his background, passion for robotics, and interest in open-source hardware.

Legrand-IMG_5660CIRCUIT CELLAR: Tell us a bit about your background. When did you first get started with electronics and engineering?

RICH: Back in 1982 when I was 12, one of my older brother’s friends was what they called a “whiz kid.” I would show up uninvited at his place because he was always creating something new, and he didn’t treat me like a snotty-nosed kid (which I was). On one particular afternoon he had disassembled a Big Trak toy (remember those?) and connected it to his Atari 800, so the Atari could control its movements. He wrote a simple BASIC program to read the joystick movements and translate them to Big Trak movements. You could then hit the return key and the Atari would play back the motions you just made. There were relays clicking and LEDs flashing, and the Big Trak did exactly what you told it to do. I had never seen a computer do this before, and I was absolutely amazed. I wanted to learn as much as I could about electronics after that. And I’m still learning, of course.

CIRCUIT CELLAR: You studied electrical engineering at both Rice University and North Carolina State University. Why electrical engineering?

RICH: I think it goes back to when I was 12 and trying to learn more about robotics. With a limited budget, it was largely a question of what I get my hands on. Back then you could go into Radio Shack and buy a handful of 7400 series parts and create something simple, but pretty amazing. Forrest Mims’s books (also available at Radio Shack) were full of inspiring circuit designs. And Steve Ciarcia’s “Circuit Cellar” column in Byte magazine focused on seat-of-the-pants electronics projects you could build yourself. The only tools you needed were a soldering iron, a voltmeter, and a logic probe. I think young people today see a similar landscape where it’s easier to get involved in electrical engineering than say mechanical engineering (although 3-D printing might change this). The Internet is full of source material and the hardware (computers, microcontrollers, power supplies, etc.) is lower-cost and easier to find. The Arduino is a good example of this. It has its own ecosystem from which you can launch practically any project or idea.

CIRCUIT CELLAR: Photography factors in a lot of your work and work history. Is photography a passion of yours?

RICH: I don’t think so, but I enjoy photography. Image processing, image understanding, machine vision—the idea that you can extract useful information from a digital image with a piece of software, an algorithm. It’s a cool idea to me because you can have multiple vision algorithms and effectively have several sensors in one package. Or in the case of Gigapan, being able to create a gigapixel imager from a fairly low-cost point-and-shoot camera, some motors, and customized photo stitching software. I’m a hardware guy at heart, but hardware tends to be expensive. Combining inexpensive hardware with software to create something that’s lower-cost—it sounds like a pretty niche idea, but these are the projects that I seem to fall for over and over again. Working on these projects is what I really enjoy.

CIRCUIT CELLAR: Prior to your current gig at Charmed Labs, you were with Gigapan Systems, which you co-founded. Tell us about how you came to launch Gigapan.

RICH: Gigapan is robotic camera mount that allows practically anyone with a digital camera to make high-resolution panoramas. The basic idea is that you take a camera with high resolution but narrow field-of-view (high-zoom) to capture a mosaic of pictures that can be later stitched together with software to form a much larger, highly-detailed panorama of the subject, whether it’s the Grand Canyon or the cockpit of the Space Shuttle. This technique is used by the Mars rovers, so it’s not surprising that a NASA engineer (Randy Sargent) first conceived Gigapan. Charmed Labs got a chance to bid on the hardware, and we designed and manufactured the first Gigapan units as part of a public beta program. (The beta was funded by Carnegie Mellon University through donations from NASA and Google.) The beta garnered enough attention to get investors and start a company to focus on Gigapan, which we did. We were on CNN, we were mentioned on Jay Leno. It was a fun and exciting time!

he first Xport was a simple circuit board with flash for program storage and an FPGA for programmable I/O.

The first Xport was a simple circuit board with flash for program storage and an FPGA for programmable I/O.

CIRCUIT CELLAR: In a 2004 article, “Closed-Loop Motion Control for Mobile Robotics“ (Circuit Cellar 169), you introduced us to your first product, the Xport. How did you come to design the Xport?

RICH: When the Gameboy Advance was announced back in 1999, I thought it was a perfect robot platform. It had a color LCD and a powerful 32-bit processor, it was optimized for battery power, and it was low-cost. The pitch went something like: “For $40 you can buy a cartridge for your Gameboy that allows you to play a game. For $99 you can buy a cartridge with motors and sensors that turns your Gameboy into a robot.” So the Gameboy becomes the “brains” of the robot if you will. I didn’t know what the robot would do exactly, other than be cool and robot-like, and I didn’t know how to land a consumer electronics product on the shelves of Toys “R” Us, so I tackled some of the bigger technical problems instead, like how to turn the Gameboy into an embedded system with the required I/O for robotics. I ordered a Gameboy from Japan through eBay prior to the US release and reverse-engineered the cartridge port. The first “Xport” prototype was working not long after the first Gameboys showed up in US stores, so that was pretty cool. It was a simple circuit board that plugged into the Gamboy’s cartridge port. It had flash for program storage and an FPGA for programmable I/O. The Xport seemed like an interesting product by itself, so I decided to sell it. I quit my job as a software engineer and started Charmed Labs.

CIRCUIT CELLAR: Tell us about the Xport Botball Controller (XBC).

RICH: The Xport turned the Gameboy into an embedded system with lots of I/O, but my real goal was to make a robot. So I added more electronics around the Xport for motor control, sensor inputs, a simple vision system, even Bluetooth. I sold it online for a while before the folks at Botball expressed interest in using it for their robot competition, which is geared for middle school and high school students. Building a robot out of a Gameboy was a compelling idea, especially for kids, and tens of thousands of students used the XBC to learn about engineering—that was really great. I never got the Gameboy robot on the shelves of Toys “R” Us, but it was a really happy ending to the project.

CIRCUIT CELLAR: Charmed Labs collaborated with the Carnegie Mellon CREATE Lab on the Qwerk robot controller. How did you end up collaborating with CMU?

RICH: I met Illah Nourbakhsh who runs the CREATE lab at a robot competition back when he was a grad student. His lab’s Telepresence Robotics Kit (TeRK) was created in part to address the falling rate of computer science graduates in the US. The idea was to create a curriculum that featured robotics to help attract more students to the field. Qwerk was an embedded Linux system that allowed you make a telepresence robot easily. You could literally plug in some motors, a webcam, and a battery, and fire up a web browser and become “telepresent” through the robot. We designed and manufactured Qwerk for a couple years before we licensed it.

The Qwerk

The Qwerk

CIRCUIT CELLAR: Pixy is a cool vision sensor for robotics that you can teach to track objects. What was the impetus for that design?

RICH: Pixy is actually the fifth version of the CMUcam. The first CMUcam was invented at  Carnegie Mellon by Anthony Rowe back in 2000 when he was a graduate student. I got involved on a bit of a lark. NXP Semiconductors had just announced a processor that looked like an good fit for a low-cost vision sensor, so I sent Anthony a heads-up, that’s all. He was looking for someone to help with the next version of CMUcam, so it was a happy coincidence.

The Pixy vision sensor

The Pixy vision sensor

CIRCUIT CELLAR: You launched Pixy in 2013 on Kickstarter. Would you recommend Kickstarter to Circuit Cellar readers who are thinking of launching a hardware product?

RICH: Before crowdfunding was a thing, you either had to self-fund or convince a few investors to contribute a decent amount of cash based on the premise that you had a good idea. And the investors typically didn’t have your background or perspective, so it was usually a difficult sell. With crowdfunding, a couple hundred people with similar backgrounds and perspectives contribute $50 (or so) in exchange for becoming the very first customers. It’s an easier path I think, and it’s a great fit for products like Pixy that have a limited but enthusiastic audience. I think of crowdfunding as a cost-effective marketing strategy. Sites like Kickstarter get huge amounts of traffic, and getting your idea in front of such a large audience is usually expensive—cost-prohibitive in my case. It also answers two important questions for hardware makers: Are enough people interested in this thing to make it worthwhile? And if it is worthwhile, how many should I make?

But I really didn’t think many people would be interested in a vision sensor for hobbyist robotics, so when faced with the task of creating a Kickstarter for Pixy, I thought of lots of excuses not to move forward with it. Case in point—if your Kickstarter campaign fails, it’s public Internet knowledge. (Yikes!) But I’m always telling my boys that you learn more from your mistakes than from your successes, so it seemed pretty lame that I was dragging my heals on the Kickstarter thing because I wanted to avoid potential embarrassment. I eventually got the campaign launched, and it was a success, and Pixy got a chance to see the light of day, so that was good. It was a lot of work, and it was psychologically exhausting, but it was really fun to see folks excited about your idea. I’d totally do it again though, and I’d like to crowdfund my next project.

CIRCUIT CELLAR: Can you tell us about one or two of the more interesting projects you’ve seen featuring Pixy?

RICH: Ben Heck used Pixy in a couple of his episodes of the Ben Heck Show ( He used Pixy to create a camera that can automatically track what he’s filming. And Microsoft used Pixy for an Windows 10 demo that played air hockey IR-Lock ( is a small company that launched a successful Kickstarter campaign that featured Pixy as a beacon detector for use in autonomous drones. All of these projects have a high fun-factor, which I really enjoy seeing.

CIRCUIT CELLAR: What’s next for Charmed Labs?

RICH: I’ll tell you about one of my crazier ideas. My wife gets on my case every holiday season to hang lights on the house. It wouldn’t be that bad, except our next-door neighbors go all-out. They hang lights on every available surface of their house—think Griswolds from the Christmas Vacation movie. So anything I do to our house looks pretty sad by comparison. I’m competitive. But I had the idea that if I created a computer-controlled light show that’s synchronized to music, it might be a good face-saving technology, a way to possibly one-up the neighbors, because that’s what it’s all about, right? (Ha!) So I’ve been working on an easy-to-set-up and low-cost way to make your own holiday light show. It’s way outside of my robotics wheelhouse. I’m learning about high-voltage electronics and UL requirements, and there’s a decent chance it won’t be cost-competitive, or even work, but my hope is to launch a crowdfunding campaign in the next year or so.

CIRCUIT CELLAR: What are your thoughts on the future of open-source hardware?

RICH: We can probably thank the Arduino folks because before they came along, very few were talking about open hardware. They showed that you can fully open-source a design (including the hardware) and still be successful. Pixy was my first open hardware project and I must admit that I was a little nervous moving forward with it, but open hardware principles have definitely helped us. More people are using Pixy because it’s fully open. If you’re interested in licensing your software or firmware, open hardware is an effective marketing strategy, so I don’t think it’s about “giving it all away” as some might assume. That is, you can still offer closed-source licenses to customers that want to use your software, but not open-source their customizations. I’ve always liked the idea of open vs. proprietary, and I’ve learned plenty from fellow engineers who choose to share instead of lock things down. It’s great for innovation.

On a different robot, a flapping winged ornithopter, we had this PC104 computer running matlab as the controller. It probably weighed about 2 pounds, which forced us to build a huge wingspan – almost 6 feet. We dreamed about adding some machine vision to the platform as well. Having just built a vision-based robot for MIT’s MASLAB competition using an FPGA paired with an Arduino – the PC104 solution started to look pretty stupid to me. That was what really got me interested embedded work. FPGAs and Microcontrollers gave you an insane amount of computing power at comparatively minuscule power and weight footprints. And so died the PC104 standard.


This interview appears in Circuit Cellar 305 (December 2015).

Engineering “Moonshot” Projects

In 2009, Andrew Meyer, an MIT-trained engineer and entrepreneur, co-founded LeafLabs, a Cambridge, MA-based R&D firm that designs “powerful physical computing devices for control and communication among smart machines (including humans).” We recently asked Andrew to tell us about his background, detail some of his most intriguing projects, tell us about his contributions to Project Ara, and share his thoughts on the future of electrical engineering.AndrewMeyerLeaflabs

CIRCUIT CELLAR: How did you become interested in electronics? Did you start at a young age?

ANDREW: Yes, actually, but I am not sure I really got anywhere fooling around as a kid. I had a deep love of remote control cars and airplanes in middle school. I was totally obsessed with figuring out how to build my own control radio. This was right before the rise of Google, and I scoured the net for info on circuits. In the end, I achieved a reasonable grasp on really simple RC type circuits but completely failed in figuring out the radio. Later in high school I took some courses at the local community college and built an AM radio and got into the math for the first time – j and omega and all that.

CIRCUIT CELLAR: What is Leaflabs? How did it start? Who comprises your team today?

ANDREW: LeafLabs is an R&D firm specializing in embedded and distributed systems. Projects start as solving specific problems for a client, but the idea is to turn those relationships into product opportunities. To me, that’s what separates R&D from consulting.


The LeafLabs Office (Source: LeafLabs)

I started LeafLabs with a handful of friends in 2009. It was an all MIT cast of engineers, and it took four or five years before I understood how much we were holding ourselves back by not embracing some marketing and sales talent. The original concept was to try and design ICs that were optimized for running certain machine learning algorithms at low power. The idea was that smartphones might want to do speech to text some day without sending the audio off to the cloud. This was way too ambitious for a group of 22 year olds with no money.

Our second overly ambitious idea was to try and solve the “FPGA problem.” I’m still really passionate about this, but it too was too much for four kids in a basement to take a big bite off. The problem is that FPGAs vendors like Xilinx and Altera have loads of expertise in silicon, but great software is just not in their DNA. Imagine if x86 never published their instruction set. What if Intel insisted on owning not just the processors, but the languages, compilers, libraries, IDEs, debuggers, operating systems, and the rest of it? Would we ever have gotten to Linux? What about Python? FPGAs have enormous potential to surpass even the GPU as a completely standard technology in computer systems. There should some gate fabric in my phone. The development tools just suck, suck, suck. If any FPGA executives are reading this: Please open up your bitstream formats, the FSF and the rest of the community will get the ball rolling on an open toolchain that will far exceed what you guys are doing internally. You will change the world.

CIRCUIT CELLAR: How did the Maple microcontroller board come about?

ANDREW: Arduino was really starting to come up at the time. I had just left Analog, where we had been using the 32-bit Cortex M3. We started asking “Chips like the STM32 are clearly the way of the future, why on earth is Arduino using a chip from the ‘90s?” Perry, another LeafLabs founder, was really passionate about this. ARM is taking over the world, the community deserves a product that is as easy to use as Arduino, but built on top of modern technology.

CIRCUIT CELLAR: Can you give a general overview of your involvement with Project Ara?

ANDREW: We got into Ara at the beginning as subcontractors to the company that was leading a lot of the engineering, NK Labs. Since then our role has expanded quite a bit, but we are still focused on software and firmware development. Everyone understood that Ara was going to require a lot of firmware and FPGA work, and so we were a natural choice to get involved. One of the first Ara prototypes actually used the Maple software library, libmaple, and had eight FPGAs in it! For your readers that are interested in Ara, please to check out and

LeafLabs is focused on firmware development. What’s really exciting to me about the project is the technology under the hood. Basically, what we have done is built a network on a PCB. The first big problem with embedded linux devices is that they are completely centered around the SoC. Change the SoC and you are in for ton of software development, for instance, to bring your display driver back to life. Similarly, changes to the design, such as incorporating a faster Wi-Fi chip, might force you to change the SoC. This severe coupling between everything keeps designers from iterating. You have this attitude of “OK, no one touch this design for the next 5 years, we finally got it working.” If we have learned anything from SaaS and App companies it’s that quickly iterating and continuous deployment are key to great products. If your platform inhibits iteration, you have a big problem.

The other problem with embedded systems is that there are so many protocols! SDIO, USB, DSI, I2C, SPI, CSI, blah blah blah. Do we really need so many!? Think how much mileage we get out of TCP/IP. The protocol explosion just adds impedance to the entire design process, and forces engineers to be worrying about bits toggling on traces rather than customer facing features.

The technology being developed for Ara, called Greybus, solves both these problems. The centerpiece of our phone is a switch, and the display, Wi-Fi, audio, baseband, etc all hang off the switch as network devices. Even the processor is just another module hanging off this network. All modules speak the same “good enough” protocol called UniPro (Unified Protocol). The possibilities here are absolutely tantalizing. To learn more about Greybus, see here:

CIRCUIT CELLAR: Can you define “minimalist data acquisition” for our readers? What is it and why does it interest you?

ANDREW: More and more fields, but particularly in neuroscience, are having to deal with outrageously huge real-time data sets. There are 100 billion neurons in the human brain. If we want to listen to just 1,000 of them, we are already talking about ~1 Gbps. Ed Boyden, a professor at MIT, asked us if we could build some hardware to help handle the torrent. Could we scale to 1 Tbps? Could we build something that researchers on a budget could actually afford and that mere mortals could use?

The Willow (Source: LeafLabs)

The Willow (Source: LeafLabs)

Willow is a hardware platform for capturing, storing, and processing neuroscience data at this scale. We had to be “minimalist” to keep costs down, and ensure our system is easy to use. Since we need to use an FPGA anyway to interface with a data source (like a bank of ADCs, or an array of image sensors), we thought, “Why not use the same chip for interfacing to storage?” With a single $150 FPGA and a couple of $200 SSD drives, we can record at 12 Gbps, put guarantees on throughput, and record for a couple of hours!

CIRCUIT CELLAR: What are you goals for LeafLabs for the next 6 to 12 months?

ANDREW: Including our superb remote contractors, our team is pushing 20. A year from now, it could be double that. This is a really tricky transition—where company culture really starts to solidify, where project management becomes a first-order problem, and where people’s careers are on the line. My first goal for LeafLabs is make sure we nail this transition and build off of a really solid foundation. Besides that, we are always looking for compelling new problems to work on and new markets to play in. Getting into neuroscience has been an absolute blast.

The complete interview appears in Circuit Cellar 298 (May 2015).

The Internet of Things: A Very Disruptive Force

We met with Geoff Lees (Senior Vice President & General Manager of Microcontrollers, Freescale) at the 2015 Embedded World Show in Nuremberg, Germany. We asked him about the Internet of Things, the big changes on the embedded systems horizon, and what it takes to be a successful engineer.L1060979

CIRCUIT CELLAR: The Embedded World Show is one of the biggest that specifically focuses on embedded technologies, new products, and design. What makes this show special?

GEOFF: In Europe we go to the Electronica in Munich and also to this show. At Electronica, we meet up with our clients and distributors. This Embedded show has a much more technical focus. Here we meet with the individual designers and technical teams of our clients and see most in-depth technical discussions. At the Electronica show we talk business; here we talk more technology and what it can do for the client.

CIRCUIT CELLAR: Talking about individual engineers, we remember last year in your press conference you mentioned a focus on hobbyists. That’s quite remarkable for a company like Freescale. We also see there is a small “maker lab” in your booth at the show.

GEOFF: It is important to address makers and hobbyists for two reasons. First, there are the sheer numbers. At Maker Show in New York, you see there a 100,000 people showing up. At a show like this, it is 20,000 to 25,000. Here we see the engineering teams of companies. But what is interesting about the maker community is that individuals can have an idea or innovation, create and build the prototypes, but instead of having a company making this, they have the community and can even go to market.L1060983

CIRCUIT CELLAR: Sometimes we get the idea that the bigger companies are looking at the crowd-funding communities as part of—or as a replacement for—their own R&D activities. How does that work for a company like Freescale?

GEOFF: One thing that’s very clear in today’s world is speed. Sometimes an individual, with very little obstruction, can have speed that cannot be matched by companies—and someone who can respond or react to the requirements almost instantaneously has an advantage. There are so many of these. Finding and communicating with them is almost an impossible task. You really have to watch carefully. It is almost impossible to know where the next innovation is coming from.

CIRCUIT CELLAR: You call the Internet of Things, the Internet of Tomorrow?

GEOFF: The IoT is a very disruptive force. It started out as a buzz, but it is in the “nature” of microcontrollers to connect and to communicate. With new Wi-Fi concepts, low-power and IPv6 the road is clear for many new applications. To demonstrate the new technologies we have a “bigger than big” truck driving through the US. We put it in the parking lot of companies and demo not only our own products, but also their products as well as the solutions of their competitors. With a show you get the designers or marketing people. With the truck we also have CEOs and CTOs for a coffee—the guys who would not even consider visiting our website!

CIRCUIT CELLAR: But how will the IoT affect us?

GEOFF: I currently have eight apps on my phone that are all IoT controls, monitoring my house, solar panels, and vehicle. I expect that number will grow. Also, devices will talk to devices and create new independent controls. “Big Ass Fans” is a nice example of that. That company is making fans but is also playing a role in home automation. Their latest model fan talks to the NEST. Only a small difference in temperature can set the fan to work rather than your air conditioning, either by cooling down or circulating the hotter air downwards.

CIRCUIT CELLAR: Everyone knows that standards are key to making the IoT really happen. What role does Freescale have in this?

GEOFF: We joined up with the Thread Group. This initiative started with only eight companies, and that number has grown to 50 in five months, and now we see around 1,000 companies that look for information. If we see a growth from eight to 50 to 1,000, you know that there is a momentum which will result in new standards. The Thread Group uses existing (IEEE 8082.15.4) technologies and standards to build a new wireless mesh protocol that will enable to overcome the current limitations in wireless home automation. The Thread Networks will aim at the simple installation of new nodes and it can scale up to 250 and more devices in a single network. No company—whether you are Cisco or IBM or Oracle—has the power to set the standard on their own, maybe a part of it, but not all. This will go as usual, an initiative will gain critical mass, and then the momentum drives it through. This will all be about momentum.

The complete interview appears in Circuit Cellar 297 (April 2015).

Advances in Haptics Research

Katherine J. Kuchenbecker is an Associate Professor in Mechanical Engineering and Applied Mechanics at the University of Pennsylvania, with a secondary appointment in Computer and Information Science. She directs the Penn Haptics Group, which is part of the General Robotics, Automation, Sensing, and Perception (GRASP) Laboratory. In this interview, she tells us about her research, which centers on the design and control of haptic interfaces for applications such as robot-assisted surgery, medical simulation, stroke rehabilitation, and personal computing.

Katherine J. Kuchenbecker

Katherine J. Kuchenbecker

CIRCUIT CELLAR: When did you first become interested in haptics and why did you decide to pursue it?

KATHERINE: I chose to become an engineer because I wanted to create technology that helps people. Several topics piqued my interest when I was pursuing my undergraduate degree in mechanical engineering at Stanford, including mechatronics, robotics, automotive engineering, product design, human-computer interaction, and medical devices. I was particularly excited about areas that involve human interaction with technology. Haptics is the perfect combination of these interests because it centers on human interaction with real, remote, or virtual objects, as well as robotic interaction with physical objects.

My first exposure to this field was a “haptic paddle” lab in a Stanford course on system dynamics, but that alone wouldn’t have been enough to make me fall in love with this field. Instead, it was conversations with Günter Niemeyer, the professor who advised me in my PhD at Stanford. I knew I wanted a doctorate so that I could become a faculty member myself, and I was inspired by the work he had done as an engineer at Intuitive Surgical, Inc., the maker of the da Vinci system for robotic surgery. Through my early research with Günter, I realized that it is incredibly satisfying to create computer-controlled electromechanical systems that enable the user to touch virtual objects or control a robot at a distance. I love demonstrating haptic systems because people make such great faces when they feel how the system responds to their movements. Another great benefit of studying haptics is that I get to work on a wide variety of applications that could potentially impact people in the near future: robotic surgery, medical training, stroke rehabilitation, personal robotics, and personal computing, to name a few.

CIRCUIT CELLAR: What is haptography? What are its benefits?

KATHERINE: I coined the term “haptography” (haptic photography) to proclaim an ambitious goal for haptics research: we should be able to capture and reproduce how surfaces feel with the same acuity that we can capture and reproduce how surfaces look.

When I entered the field of haptics in 2002, a lot of great research had been done on methods for letting a user feel a virtual three-dimensional shape through a stylus or thimble. Essentially, the user holds on to a handle attached to the end of a lightweight, back-drivable robot arm; the 3D Systems Touch device is the most recent haptic interface of this type. A computer measures the motion that the person makes and constantly outputs a three-dimensional force vector to give the user the illusion that they are touching the object shown on the screen. I was impressed with the haptics demonstrations I tried back in 2002, but I was also deeply disappointed with how the virtual surfaces felt. Everything was soft, squishy, and indistinct compared to how real objects feel. That’s one of the benefits of being new to a field; you’re not afraid to question the state of the art.

I started working to improve this situation as a doctoral student, helping invent a way to make hard virtual surfaces like wood and metal feel really hard and realistic. The key was understanding that the human haptic perceptual system keys in on transients instead of steady-state forces when judging hardness. I had to write a research statement to apply for faculty positions at the end of 2005, so I wrote all about haptography. Rather than trying to hand-program how various surfaces should feel, I wanted to make it all data driven. The idea is to use motion and force sensors to record everything a person feels when using a tool to touch a real surface. We then analyze the recorded data to make a model of how the surface responds when the tool moves in various ways. As with hardness, high-frequency vibration transients are also really important to human perception of texture, which is a big part of what makes different surfaces feel distinct. Standard haptic interfaces weren’t designed to output high-frequency vibrations, so we typically attach a voice-coil actuator (much like an audio speaker) to the handle, near the user’s fingertips. When the user is touching a virtual surface, we output data-driven tapping transients, friction forces, and texture vibrations to try to fool them into thinking they are touching the real surface from which the model was constructed.

After many years of research by my PhD students Heather Culbertson and Joe Romano, we’ve been able to create the most realistic haptic surfaces in the world. My work in haptography is motivated by a belief that there are myriad applications for highly realistic haptic virtual surfaces.

One exciting use is in recording what doctors and other clinical practitioners feel as they use various tools to care for their patients, such as inserting an epidural needle or examining teeth for decay (more on this below). Haptography would enable us to accurately simulate those interactions so that trainees can practice critical perceptualmotor skills on a computer model instead of on a human patient.

Another application that excites us is adding tactile feedback to online shopping. We’d love to use our technology to let consumers feel the fabrics and surfaces of products they’re considering without having to visit a physical store. Touch-mediated interaction plays an important role in many facets of human life; I hope that my team’s work on haptography will help bring highly realistic touch feedback into the digital domain.

Read Circuit Cellar’s interviews with other engineers, academics, and innovators.

CIRCUIT CELLAR: Which of the Penn Haptics Group’s projects most interest you at this time?

KATHERINE: That’s a hard question! I’m excited about all of the projects we are pursuing. There are a few I can’t talk about, because we’re planning to patent the underlying technology once we confirm that it works as well as we think it does. Two of those that are in the public domain have been fascinating me recently. Tactile Teleoperation: My lab shares a Willow Garage PR2 (Personal Robot 2) humanoid robot with several of the other faculty in Penn’s GRASP Lab. Our PR2’s name is Graspy.

This wearable device allows the user to control the motion of the PR2 robot’s hand and also feel what the PR2 is feeling. The haptic feedback is delivered via a geared DC motor and two voice-coil actuators.

This wearable device allows the user to control the motion of the PR2 robot’s hand and also feel what the PR2 is feeling. The haptic feedback is delivered via a geared DC motor and two voice-coil actuators.

While we’ve done lots of fun research to enable this robot to autonomously pick up and set down unknown objects, I’d always dreamed of having a great system for controlling Graspy from a distance. Instead of making the operator use a joystick or a keyboard, we wanted to let him or her control Graspy using natural hand motions and also feel what Graspy was feeling during interactions with objects.

My PhD student Rebecca Pierce recently led the development of a wearable device that accomplishes exactly this goal. It uses a direct drive geared DC motor with an optical encoder to actuate and sense a revolute joint that is aligned with the base joint of the operator’s index finger. Opening and closing your hand opens and closes the robot’s paralleljaw gripper, and the motor resists the motion of your hand if the robot grabs onto something. We supplement this kinesthetic haptic feedback with tactile feedback delivered to the pads of the user’s index finger and thumb. A voice coil actuator mounted in each location moves a platform into and out of contact with the finger to match what the robot’s tactile sensors detect. Each voice coil presses with a force proportional to what the corresponding robot finger is feeling, and the voice coils also transmit the high-frequency vibrations (typically caused by collisions) that are sensed by the MEMS-based accelerometer embedded in the robot’s hand. We track the movement of this wearable device using a Vicon optical motion tracking system, and Graspy follows the movements of the operator in real time. The operator sees a video of the interaction taking place. We’re in the process of having human participants test this teleoperation setup right now, and I’m really excited to learn how the haptic feedback affects the operator’s ability to control the robot.

high-bandwidth MEMS-based accelerometer records the sensations a dentist feels as she probes an extracted human tooth. Feeling these recordings lets dental trainees practice diagnosing dental decay before they treat live patients.

The high-bandwidth MEMS-based accelerometer records thesensations a dentist feels as she probes an extracted human tooth. Feeling these recordings lets dental trainees practice diagnosing dental decay before they treat live patients.

CIRCUIT CELLAR: In your TEDYouth talk, you describe a project in which a dental tool is fitted with an accelerometer to record what a dentist feels and then replay it back for a dental student. Can you tell us a bit about the project?

KATHERINE: This project spun out of my haptography research, which I described above. While we were learning to record and model haptic data from interactions between tools and objects, we realized that the original recordings had value on their own, even before we distilled them into a virtual model of what the person was touching. One day I gave a lab tour to two faculty members from the Penn School of Dental Medicine who were interested in new technologies. I hit it off with Dr. Margrit Maggio, who had great experience in teaching general dentistry skills to dental students. She explained that some dental students really struggled to master some of the tactile judgments needed to practice dentistry, particularly in discerning whether or not a tooth surface is decayed (in popular parlance, whether it has a cavity). A few students and I went over to her lab to test whether our accelerometer-based technology could capture the subtle details of how decayed vs. healthy tooth tissue feels. While the recordings are a little creepy to feel, they are super accurate. We refined our approach and conducted several studies on the potential of this technology to be used in training dental students. The results were really encouraging, once again showing the potential that haptic technology holds for improving clinical training.

CIRCUIT CELLAR: What is the “next big thing” in the field of haptics? Is there a specific area or technology that you think will be a game changer?

KATHERINE: Of course this depends on where you’re looking. While cell phones and game controllers have had vibration alerts for a long time, I think we’re just starting to see highquality haptic feedback emerge in consumer products. Haptics can definitely improve the user experience, which will give haptic products a market advantage, but their cost and implementation complexity need to be low enough to keep the product competitive. On the research side, I’m seeing a big move toward tactile feedback and wearable devices. Luckily there are enough interesting open research questions to keep my students and me busy for 30 more years, if not longer!

The complete interview appears in Circuit Cellar 296 (March 2015).

Application Engineering: An Interview with Carmen Parisi

Carmen Parisi is an applications engineer who co-hosts an engineering podcast in his spare time. In this interview, he describes his work, shares some engineering tips, and  tells us about a fun prank he played on an unsuspecting designer.

CIRCUIT CELLAR: Where are you located?

CARMEN: Currently, I’m living and working in Raleigh-Durham, NC, around the Research Triangle Park area between the two cities with my wife and new dog Sadie. Kelly and I moved down about three years ago from Buffalo, NY, and really like it here. There’s a lot of tech companies and engineers around, tons of stuff to do, and great food and beer scenes. Plus, as a hearty Northerner, I get to laugh at the “cold” winters we experience. Come summer, though, I melt into a puddle on the pavement. Snow all the way for me, but Kelly disagrees.

Carmen Parisi

Carmen Parisi

CIRCUIT CELLAR: When did you decide to pursue electrical engineering and why?

CARMEN: Ever since I was a kid I had a fascination with tools and how things worked. I would always have a toy sword and various tools stuffed into my belt and would volunteer to help my dad around the house building a deck around the pool or fixing the fence.

Once I got into high school, I took a few basic engineering courses during which time I got bit by the engineering bug. The course that really “doomed” me to a life of electronics was a Robotics course taught by my favorite teacher C, as we called him. He put me through my paces learning how to solder, reading schematics, programming in BASIC, and robbing Fort Knox using a LEGO Mindstorms robot. C’s class solidified my choice to go to college for engineering, and shortly thereafter, I picked electrical over mechanical for my major.

CIRCUIT CELLAR: When was the first time you used a microcontroller in a project?

CARMEN: If we’re counting LEGO Mindstorms, then the Robotics class in tenth grade with C where we had to build a robot to lift a golden brick and run away with it (thus “robbing Fort Knox”). I met all the individual milestones with my group for the project, but we couldn’t get the whole thing working smoothly from beginning to end. I guess that was my first time learning how to successfully fail too which has turned out to be a very useful skill.

My first real microcontroller experience was the summer after sophomore year when I took a college course at a local community college offering a few classes to high school students interested in engineering. During that course I learned more basic circuit theory, got introduced briefly to SMT soldering, and built some robots using the Parallax BOE Bot. Looking back, I’d say this was the time my analog career kicked off as I slowly started to realize that I was more interested in the circuits themselves than the overall robot.

CIRCUIT CELLAR: Tell us about your university-level schooling.

CARMEN: I still consider myself a student in that I’m always looking to learn new things and grow as an engineer, but my formal schooling is over for the foreseeable future. In 2011, I completed a combined BS/MS degree in Electrical Engineering at the Rochester Institute of Technology in Rochester, NY. I initially started off interested in robotics but after working with a great analog designer on my first co-op at GE, I switched into the analog circuit and semiconductor track and never looked back.

CIRCUIT CELLAR: Can you tell us about your work in graduate school?

CARMEN: Sure thing. My graduate work was primarily with the Communications professor who needed a proof of concept built to test out a theory that looked plausible on paper. Prior to my joining the Comms Lab, my advisor and two past grad students had worked out a method of securing wireless channels using the randomness of the channel itself. There was an initial front end of sorts to test the idea out but I don’t think it was ever tested.

I looked over the circuit design, decided to scrap it and start fresh, and immediately realized I had a big job ahead of me. Cue the analog professor becoming my co-advisor. Mixing circuits, active filters, phase detectors, ADCs, and communication theory swam through my head as I slowly cajoled the circuit to life. Two PCB revisions later the circuit worked in that it took the RF input signal and spat out some bits at the other end, but after my advisor applied his algorithm to the data, we weren’t able to generate symmetric keys on different boards. Whether this was from an error in theory or with my board I never found out, as I ended the project there to focus on my full-time job leaving with a grad paper instead of a full thesis.

I still have all my old lab notebooks, schematics, and board layouts on my bookshelf at home. I think the files are sitting on a hard drive somewhere too. Looking at them now, I can spot a lot of little errors I’d like to fix due to my inexperience at the time and some maybe a few not so little errors too.

CIRCUIT CELLAR: What did you do after school?

CARMEN: After I left RIT, I moved down here to Raleigh-Durham to start my career as an Applications Engineer working on switching regulators with Intersil. Back in 2009 I had done a summer stint as an FAE at a small field office in Long Island with the company which got me interested in working in the semiconductor industry.

Life on the road as an FAE didn’t appeal to me after spending my college years constantly moving around for co-ops, so my former boss set me up with an interview here at the RTP design center. On the way down for the interview, I got stuck in Dulles for the night thanks to some bad weather in Rochester causing me to miss my connection. I wound up getting a bare 3 hours of sleep that night on an empty terminal bench. The next morning, groggy and sleep deprived, I suited up in the family restroom and flew out for six wonderful hours of technical interviews. I was absolutely wiped out by the end of the day but managed to survive the ordeal. The rest is history.

CIRCUIT CELLAR: Tell us about the work you are doing as an applications engineer for Intersil.

CARMEN: Well, for starters, being an apps engineer is exactly the rock n’ roll lifestyle I’m sure all your readers expect it to be. I roll into the office every morning and have the roadies warm up my iron for me!

In reality though, I work on buck regulators for computing applications like notebooks, tablets, ultrabooks, with maybe a bit of desktop work from time to time. Most of the parts I work on are for the primary core voltage on Intel processors. Sometimes, should the part integrate multiple regulators, I’ll work on a graphics rail or one of the other many voltage rails present on a motherboard. For each new processor tock (tick? I always confuse the two), Intel releases a laundry list of specs that have to be met in order to provide power to their CPUs and my parts are designed to those specs.

When I work apps on a brand spanking new chip, I’ll first work with the design engineers to run some feasibility studies and help define any new features for the IC. These tests range from tuning a similar part to the new Intel specs to see if the control scheme hits any corners or has stability issues to beating up some power FETs to determine if they can handle the new current requirements we have to meet. Once the chip tapes out, I’ll start work on preliminary documentation—a rough datasheet draft or early reference design based on feasibility testing and simulations—for the field to use when working with customers. During this time, I also design the evaluation board I’ll use to validate the part and send to customers for sampling.

The real meat and potatoes of my job is silicon validation. I’ve got an exhaustive spreadsheet of bench tests to do that functionally verify the IC over a wide range of corners. The first few weeks after silicon comes back I’m working full throttle, round the clock if need be, to make sure there are no show stopping bugs we need to address. I never see my office during validation. Instead I’m spending all my time in the lab hunched over the eval board or squinting at my scope.

Things calm down slightly after the initial validation, but the work is still nowhere near done. Now I’m working with design and test engineers to debug any issues that crept up during validation and implement fixes. Ideally, a board-level change is found because PCB or apps level schematic changes are much easier and cheaper than silicon spins. In conjunction with this work, I’ll also refine my reference designs and documentation as well as work with the field on initial customer designs by answering questions and checking over layouts and schematics to make sure everything’s optimal for their builds.

Up until the part releases, I’ll continue cycling through validation, debug, and customer support as needed, squeezing in documentation when I get a chance too. At any given time, I’m also supporting old parts still in production or, if I’m in a lull with my work, getting pulled onto other chips to help out other apps engineers in a jam.

The last part I released, and my first as the lead apps guy, was the ISL95813, a single phase regulator for Haswell and Broadwell systems. My next part is scheduled for release next year which I can’t talk too much about, but it’s really cool.

CIRCUIT CELLAR: During your time at Intersil, you must have learned some important lessons about professional engineering. Can you share one or two things you took from the experience?

CARMEN: Most importantly, good communication skills are key. A large chunk of my job is talking to other engineers and customers across the country and overseas. Their whole interaction with me is through the emails and reports I send out and I want to make sure they’re top notch. You don’t need to be a poet laureate by any means, but if you come across like a rock head, it will be much harder to get taken seriously and problems will drag out longer than necessary. Proofread your work; make sure you’re getting your point across clearly; and tailor your email, report, PowerPoint, whatever, to your audience’s level of technical expertise. Study up on how to make a slideshow that won’t bore your audience or read a technical writing guide. It can’t hurt.

Secondly, document, document, document—even if it’s only for your own reference. And keep it somewhat organized so you can find what you need again without too much hassle. Yes, it can help CYA, but also I’ve saved myself a ton of time not redoing the same derivations or looking back at a difficult test setup I had documented in my notebooks. It’s especially nice being able to pull up old data from past parts to see why the heck we did what we did years later.

CIRCUIT CELLAR: Tell us about your most recent electrical engineering project. What did you build and why?

CARMEN: Well, I can’t talk too much about work since all my projects at the moment are either customer related or under development, but suffice it to say I’m working on a lot of low power, multi-role chips.

Outside of work though for nearly two years now I’ve been co-hosting a podcast which keeps me plenty busy. The show’s called The Engineering Commons and it gets released every other week by myself and three other engineers scattered across the US. It was originally started by Chris Gammell and Jeff Shelton, but when Chris left the show for other projects back in 2013, I threw my hat into the ring when Jeff put the word out he was looking for new co-hosts. We discuss the engineering discipline as a whole rather than focus on any one field and some of our favorite topics include education, the value of co-ops, life in the workplace, and the stories of other engineers we bring on to interview.

The semiconductor field is pretty niche, and so through the show, I get exposed to all sorts of new ideas and philosophies, whether it’s from researching a topic when coming up with show notes or hearing the stories of engineers and professors from across the globe. Some of my favorite episodes are the ones while interviewing a guest I barely have to say anything and not just because I hate hearing my voice when I re-listen to an episode! Hearing someone get really into a story and talk about their passion I can’t help but get drawn in and become excited myself. All us engineers are alike; no matter the field once you get us going about that tricky bug we finally tracked down, the ridiculous meeting that happened the other day, or those ah-ha moments when a solution just clicks in your head we just can’t help but gush and it makes for great content. I’ve put out nearly 50 episodes with Jeff, Adam, and Brian, and I can’t wait to do the next 50!

CIRCUIT CELLAR: Tell our readers about the prank circuit gag you pulled on the designer you worked with. And can you share an image of the prank circuit?

CARMEN: A good way through the 813 development I found some problems that ended up being non-issues because I misinterpreted a spec, had a test setup issue, or made a silly component choice in my design. The designer started ribbing me a bit by immediately calling everything a board issue from that point on. This kind of back and forth goes on all the time between apps and design and it’s always good natured in tone. I didn’t take it personally and took strides to be more thorough before ringing alarm bells going forward but I couldn’t let him get way Scot-free.

Prank circuit

Prank circuit

With my boss’ permission I waited until a slow day came along and rigged up a little circuit to the bottom of the eval board that would overdrive the compensation node of our regulator, propagate through the control loop, and cause seemingly random spikes in the output voltage. I took some waveforms and sent them off to the designer explaining how I found an operational corner that affected regulation we needed to address. Since he was a thorough designer and liked to regularly pop into the apps lab I actually spent my morning running the tests he asked me to just to keep up the illusion something was wrong if he showed up.

I kept him digging through the schematics trying to find his mistake until mid-afternoon before I brought him in the lab and slowly flipped the board over while telling him I found the error was caused by a parasitic circuit. At this point a couple other engineers who were in on the gag had found reasons to be in the lab for the reveal and we all had a good laugh. The designer took it pretty well, and I even bought him a beer for being a good sport.

You can read the entire interview in Circuit Cellar 295 (February 2015).

DIY Interactive Robots: An Interview with Erin Kennedy

Erin “RobotGrrl” Kennedy designs award-winning robots. Her RoboBrrd DIY robot-building kit successfully launched in 2012 and was featured in IEEE Spectrum, Forbes, Wired, and on the Discovery Channel. Erin was recognized as  one of the 20 Intel Emerging Young Entrepreneurs. In this interview she tells us about her passion for robotics, early designs, and future plans.5938310667_89a68ca380_o

CIRCUIT CELLAR: How and when did Erin Kennedy become “RobotGrrl?”

ERIN: I used to play an online game, but didn’t want to use my nickname from there. I was building LEGO robots at the time, so my friend suggested “RobotGrrl.” It sounds like a growl without the “ow.”

CIRCUIT CELLAR: Tell us about Why and when did you decide to start blogging?

ERIN: I started around 2006 to document my adventures into the world of robotics. I would post updates to my project on there, similar to a log book. It helped me gain a community that would follow my adventures.

CIRCUIT CELLAR: Your RoboBrrd company is based on the success of your RoboBrrd beginner robot-building kit, which was funded by Indiegogo in 2012. How does the robot work? What is included in the kit?

ERIN: RoboBrrd works by using three servos, a laser-cut chassis, and an Arduino derivative for its brain. Two of the servos are used for the robot’s wings and the third one is used for the beak mechanism. To construct the chassis, all you need is glue. The brains are on a custom-designed Arduino derivative, complete with RoboBrrd doodles on the silkscreen.



The first prototype of RoboBrrd was created with pencils and popsicle sticks. Adafruit sent me the electronics and in return I would make weekly videos about building the robot. People seemed to like the robot, so I kept making newer prototypes that would improve on problems and add more to the design.

Eventually I started working on a laser-cut kit version. I won the WyoLum Open Hardware grant and, with the money, I was able to order PCBs I designed for RoboBrrd.

I had enough money for a flight out to California (for RoboGames and Maker Faire Bay Area) where I was an artist in residence at Evil Mad Scientist Laboratories. It was helpful to be able to use their laser cutter right when a new design was ready. Plus, I was able to build a really old and cool Heathkit.

RoboBrrd chassis

RoboBrrd chassis

Afterward, I worked on the design a little more. SpikenzieLabs ( helped laser cut it for me and eventually it was all finished. It was such an awesome feeling to finally have a solid design!

In 2012, RoboBrrd launched on Indiegogo and luckily there were enough friends out there who were able to help the project and back it. They were all very enthusiastic about the project. I was really lucky.

Now I am working on a newer version of the 3-D printed RoboBrrd and some iOS applications that use Bluetooth Low Energy (BLE) to communicate with it. The design has come a long way, and it has been fun to learn many new things from RoboBrrd.

CIRCUIT CELLAR: RoboBrrd has had widespread popularity. The robots have been featured on The Discovery Channel, Forbes, MAKE, and WIRED. To what do you attribute your success?

ERIN: The success of RoboBrrd is attributed to everyone who is enthusiastic about it, especially those who have bought a kit or made their own RoboBrrds. It is always fun to see whenever people make modifications to their RoboBrrds.

All I did was make and deliver the kit. It’s all of the “friends of RoboBrrd” who bring their own creative ideas to make it really shine. Also, from the previous question, the readers can see that I had a lot of help along the way.

Having the robots featured on many websites required some luck. You never know if your e-mail pitch is what the journalists are looking for to cover the robot. I was really lucky that websites featured RoboBrrd; it provides it with a little more credibility.

In my opinion, the quirkiness of RoboBrrd helps as well. Sometimes people view it as the “open-source hardware (OSHW) Furby.” It’s a robotic bird and it isn’t your regular wheeled-robot.

CIRCUIT CELLAR: What was the first embedded system you designed. Where were you at the time? What did you learn from the experience?

ERIN: There were systems that I designed using the LEGO Mindstorms RCX 2.0, but my very first design from scratch was a robot called BubbleBoy. The outer appearance looked like a pink snowman. It sat on a green ice cream container and wore a top hat. It was very rudimentary. At the time I was in Grade 11.

Inside of the body sphere were two servos. The servos would push/pull on paper clips that were attached to the head. Inside the head there was a DC motor to spin the top hat around. There was also a smaller DC motor inside the body to attach to a hula hoop to wiggle it. The electronics were enclosed in the container. The robot used an Arduino Diecimila microcontroller board (limited-edition prototype version) and some transistors to control the motors from battery power. There was also a LCD to display the robot’s current mood and water and food levels. On each side of the screen buttons incremented the water or food levels.

There’s a 2009 video of me showing BubbleBoy on Fat Man & Circuit Girl. (Jeri Ellsworth co-hosted the webcast.)

There was not as much documentation online about the Arduino and learning electronics as there is now. I gained many skills from this experience.

The biggest thing I learned from BubbleBoy was how to drive DC motors by using transistors. I also learned how to not mount servos. The hot glue on polystyrene was never rigid enough and kept moving. It was a fun project; the hands-on making of a robot character can really help you kick off making bigger projects.

You can read the entire interview in Circuit Cellar 293 (December 2014).

Electrical Engineering Innovation & Outreach

Bill Porter is a Panama City Beach, FL-based electronics engineer working for the US Navy. When he isn’t working on unmanned systems for the Navy, he spends his time running an engineering-focused educational outreach program and working on his own projects. In this interview, Bill talks about his first designs, technical interests, and current projects.

CIRCUIT CELLAR: You’re an electronics engineer for the United States Navy. Can you describe any of the projects you’re involved with?

BILL: I work with unmanned systems, or robots that are teleoperated and/or autonomous. This includes systems that swim under water, on the surface, or across the land. The Navy is working hard to develop robots to do the jobs that are dirty, dangerous, or dull and help keep the sailor out of harm’s way. One such system is called MUSCL, or Modular Systems Craft Littoral. MUSCL is a small, man-portable surface vehicle that is used by Riverine Patrol for remote surveillance and reconnaissance. I was the lead electrical engineer for the project.

Besides robots, I am also working on a few education outreach programs that work towards getting more students interested in STEM careers.

CIRCUIT CELLAR: Tell us about The Science Brothers nonprofit outreach program. How did the program start?

BILL: The Science Brothers is my main educational outreach program run out of my Navy base. For two Fridays every month, a few of my coworkers and I will visit a local elementary school to put on a show. The script of the show centers on the dynamics of two brothers, who specialize in different fields and argue over whose science is “cooler.” The result is a fun and wacky trip exploring different premises in science, such as light, sound, and energy, with examples and demonstrations from the realms of chemistry, physics, and electricity.

Science Brothers show

Science Brothers show

The program restarted when a few coworkers and I sat down and decided to bring back an old program that had existed on the base in the ‘90s called “Dr. Science.” The goal of the program was to bring science-based experiments to the schools using equipment they otherwise were not able to afford. By wowing the students with the spectacular-looking demos, we get them excited about science and yearning to learn more.

CIRCUIT CELLAR: Your website ( includes projects involving 3-D printing, motor controllers, and LEDs. What types of projects do you prefer working on and why?

BILL: I am a hardware guy. I love to fire up my favorite PCB CAD software just to get an idea out of my head and on the screen. I do not breadboard very often, as I would rather take my chances trying some new idea on a board first. Either it works, or I have an excuse to design another PCB. Thankfully, group-order PCB services have enabled my addiction tinkering at a very low cost. I wish I was stronger at mechanical CAD design to really get the full potential out of my 3-D printer, but I have done well enough without it. It really does come in handy at times, whether it is a quick project enclosure, a mount, or a part for our garden.

Bill is self-proclaimed "hardware guy"

Bill is self-proclaimed “hardware guy”

CIRCUIT CELLAR: Do you have a favorite project?

BILL: Yes! My wedding of course! I married the girl of my dreams who is just as much as a geek as I am, and as a result, we had an extremely geeky wedding over a year in the making involving many projects throughout. So much so that our theme was “Circuit and Swirls” and we carried the motif throughout.

Wedding gadgets

Wedding gadgets

We designed and made our own wedding invitations involving LEDs, a microprocessor, and a clever Easter egg. Furthermore, we 3-D-printed our centerpieces, built up our own “e-textile” wedding attire with LEDs and EL wire, and we even had a “soldering ceremony” during the event. It made our parents nervous, but in the end, everyone had a good time. Did I mention I asked her to marry me on a PCB she designed for a project?

EE-themed wedding invitations

EE-themed wedding invitations

CIRCUIT CELLAR: Are you currently working on or planning any projects? Can you tell us about them?

BILL: I have one main project that is taking up all my time at work and at home. A coworker and I are the technical directors for the first-ever Maritime RobotX Challenge. The challenge, sponsored by Association for Unmanned Vehicle Systems International (AUVSI) Foundation and by the Office for Naval Research (ONR), will take place this October in Singapore. It will include 15 teams of college students from five participating nations and put them to the test by challenging them to design a robot that will complete five tasks autonomously. As one of the technical directors, I have been helping design and build the interactive course elements that the teams’ robots will be facing. Find out more at

CIRCUIT CELLAR: What new technologies excite you and why?

BILL: I have always been infatuated by LEDs and ways to conserve energy, so I am most excited to see how efficient LEDs are starting to take over as the new source of light in the household.

The complete interview appears in Circuit Cellar 291 (October 2014).

Q&A: Electrical Engineer & FPGA Enthusiast

Chris Zeh is a San Jose, CA-based hardware design engineer who enjoys working with FPGA development boards, application-specific integrated circuits, and logic analyzers. He recently told us about the projects he is involved with at STMicroelectronics and explained what he’s working on in his free time.

CIRCUIT CELLAR: Tell us about Why and when did you decide to start a blog?

ZehCHRIS: I started blogging in the winter of 2009, a little more than a year after I graduated Colorado State University with a BSEE. I realized that after graduating it was important to continue working on various projects to keep my mind and skills sharp. I figured the best way to chronicle and show off my projects was to start a blog—my little corner of the Internet.

CIRCUIT CELLAR: What types of projects do you feature on your site?

CHRIS: I like working on a wide range of different types of projects, varying from software development to digital and analog design. I’ve found that most of my projects highlighted on have been ones focusing on FPGAs. I find these little reprogrammable, multipurpose ICs both immensely powerful and fascinating to work with.

My initial plan for the blog was to start a development project to create an FPGA equivalent to the Arduino. I wanted to build a main board with all the basic hardware to run an Altera Cyclone II FPGA and then create add-on PCBs with various sensors and interfaces. My main FPGA board was to be named the Saturn board, and the subsequent add-on “wings” were to be named after the various moons of Saturn.

a—Chris’s Saturn board prototype includes an Altera Cyclone II FPGA and JTAG FPGA programmer, two linear regulators, a 5-V breadboard power supply, and a 24-MHz clock. b—A side view of the board

a—Chris’s Saturn board prototype includes an Altera Cyclone II FPGA and JTAG FPGA programmer, two linear regulators, a 5-V breadboard power supply, and a 24-MHz clock. b—A side view of the board

The project proceeded nicely. I spent some time brushing up on my Photoshop skills to put together a logo and came up with a minimized BOM solution to provide power to the nine different voltage supplies, both linear regulators and switched-mode supplies. One aspect of FPGAs that can make them costly for hobbyist is that the programming JTAG cable was on the order of $300. Fortunately, there are a few more affordable off-brand versions, which I used at first. After many weeks of work, I finally had the total solution for the main FPGA board. The total cost of the prototype system was about $150. Eventually I came up with a way to bit bang the FPGA’s programming bitstream using a simple $15 USB-to-UART IC breakout board driven by a tiny Python application, eliminating the need for the pricey cable. This Future Technology Devices International FT232RL USB-to-UART IC also provided a clock output enabling me to further reduce the component count.

The project was a success in that I was compelled to completely digest the FPGA’s 470-page handbook, giving me a solid grasp of how to work with FPGAs such as the Cyclone II. The project was a failure in that the FPGA breakout board I wanted to use for the project was discontinued by the manufacturer. Creating and fabricating my own four-layer board and hand soldering the 208-pin package was both prohibitively expensive and also a little daunting.

Fortunately, at that time Terasic Technologies introduced its DE0-Nano, a $79 commercial, $59 academic, feature-packed FPGA evaluation board. The board comes with two 40-pin general I/O plus power headers, which has become a perfect alternative base platform for FPGA development. I now intend to develop add-on “wings” to work with this evaluation board.

CIRCUIT CELLAR: Tell us more about how you’ve been using Terasic Technologies’s DE0-Nano development and education board.

CHRIS: The main project I’ve been working on lately with the DE0-Nano is creating and adding support for a full-color 4.3” (480 × 272 pixel) thin- film transistor (TFT) touchscreen LCD. Because of the large pin count available and reconfigurable logic, the DE0-Nano can easily support the display. I used a Waveshare Electronics $20 display, which includes a 40-pin header that is almost but not quite compatible with the DE0-Nano’s 40-pin header. Using a 40-pin IDC gray cable, I was able to do some creative rewiring (cutting and swapping eight or so pins) to enable the two to mate with minimal effort. Eventually, once all the features are tested, I’ll fabricate a PCB in place of the cable.

There are many libraries available to drive the display, but for this project I want to develop the hardware accelerators and video pipeline from the ground up, purely though digital logic in the FPGA. I recently picked up an SD card breakout board and a small camera breakout board. Using these I would like to start playing around with image processing and object recognition algorithms.

CIRCUIT CELLAR: What do you do at STMicroelectronics and what types of projects are you working on?

CHRIS: My official title is Senior Hardware Design Engineer. This title mainly comes thanks to the first project I worked on for the company, which is ongoing—an FPGA-based serial port capture and decoding tool named the HyperSniffer. However, my main role is that of an application engineer.

I spend most of my time testing and debugging our prototype mixed-signal ASICs prior to mass production. These ASICs are built for the hard disk drive industry. They provide several switch-mode power supplies, linear regulators, brushless DC motor controllers, voice coil motor actuation, and a shock sensor digital processing chain, along with the various DACs, ADCs, and monitoring circuits all integrated into a single IC.

Our ASIC’s huge feature set requires me to stay sharp on a wide variety of topics, both analog and digital. A typical day has me down in the lab writing scripts in Python or Visual Studio, creating stimuli, and taking measurements using my 1-GHz, 10-GSPS LeCroy WavePro 7100A oscilloscope, several 6.5-digit multimeters, dynamic signal analyzers, and noise injection power supplies among other instruments. I work closely with our international design team and our customers to help discover and document bugs and streamline the system integration.

A few years back I was able to join my colleagues in writing “Power Electronics Control to Reduce Hard Disk Drive Acoustics Pure Tones,” an Institute of Electrical and Electronics Engineers (IEEE) paper published for the Control and Modeling for Power Electronics (COMPEL) 2010 conference. I presented the paper, poster, and demonstration at the conference discussing a novel technique to reduce acoustic noise generated by a spindle motor.

Chris designed the HyperSniffer logic analyzer, which is shown with the HyperDrive main board. (The PCB was designed by Vincent Himpe and Albino Miglialo.)

Chris designed the HyperSniffer logic analyzer, which is shown with the HyperDrive main board. (The PCB was designed by Vincent
Himpe and Albino Miglialo.)

CIRCUIT CELLAR: Tell us more about the HyperSniffer project.

CHRIS: The HyperSniffer project is an FPGA- based digital design project I first created right out of college. (My colleagues Vincent Himpe and Albino Miglialo did the board design and layout.) The tool is basically an application-specific logic analyzer. It enables us to help our customers troubleshoot problems that arise from serial port transmissions between their system-on-a-chip (SoC) and our ASIC. Through various triggering options it can collect and decode the two or three wire data transmissions, store them on on- board memory, and wait for retrieval and further processing by the application running on the PC. One of this tool’s nice features is that it is capable of synchronizing and communicating with an oscilloscope, enabling us to track down problems that happen in the analog domain that arise due to commands sent digitally.

You can read the entire interview in Circuit Cellar 290 (September 2014).

Q&A: Embedded Systems Training Expert

Professional engineer Jason Long worked as an embedded systems designer for more than a decade. In 2010 he founded Engenuics Technologies. Jason lives in Victoria, BC, where he continues growing his company alongside the MicroProcessor Group (MPG) embedded systems hardware teaching program he developed in 2000.


CIRCUIT CELLAR: In 2010 you founded your company Engenuics Technologies ( based on the success of the MicroProcessorGroup (MPG) program. Give us a little background. How did the MPG begin?

JASON: MPG started way back in 2000 at the University of Calgary when I was doing my undergraduate studies. I figured out that embedded systems was exactly what I wanted to do, but struggled to find enough hands-on learning in the core curriculum programs to satisfy this new appetite. I was involved in the university’s Institute of Electrical and Electronics Engineers (IEEE) student branch, where someone handed me my first Microchip Technology PIC microcontroller and ran a few lunchtime tutorials about getting it up and running. I wanted more, and so did other people.

Jason Long

Jason Long

I was also very aware that I needed to drastically improve my personal confidence and my ability to speak in public if I was going to have any luck with a career outside of a cubicle, let alone survive an interview to get a job in the first place. The combination of these two things was the perfect excuse/opportunity to start up the MPG to ensure I kept learning by being accountable to teach people new stuff each week, but also to gain the experience of delivering those presentations.

I was blown away when there were almost 30 people at the first MPG meeting, but I was ready. Two things became very clear very quickly. The first was that, to be able to teach, you must achieve a whole new level of mastery about your subject, but it was also okay to say, “I don’t know” and find out for next week. The second was that I could, in fact, get my nerves under control as long as I was prepared and didn’t try to do too much. I’m still nervous every time I start a lecture, even 14 years later, but now I know how to use those nerves! The best part was that people really appreciated what I was doing and perhaps were a bit more tolerant since MPG is free. I found a love for teaching that I didn’t expect, nor did I get how rewarding the endeavor would be.

When I was wrapping up the ninth year of the program, I considered giving it one more year and then calling it quits. I took a moment to look back at what the program was when I started and where it had come to—it had indeed evolved a lot, and I figured I had put in about 2,000 h by this point. It seemed like a waste to throw in the towel. I also looked at the relationships that had come from the program, both personally and professionally, and realized that the majority of my career and who I had become professionally had really been defined by my work with MPG. But the program—even though it was still just in Calgary—was too big to keep as a side project. I had $10,000 in inventory to support the development boards, and although all monies stayed in the program, there were thousands of dollars exchanging hands. This was a business waiting to happen, though I had never thought of myself as an entrepreneur. I was just doing stuff I loved.

This ARM-based development board is made by Jason’s company, Engenuics Technologies.

This ARM-based development board is made by Jason’s company, Engenuics Technologies.

Around the same time I discovered SparkFun Electronics, and more importantly, I discovered the story of how the company got started by Nathan Seidie. That story begins almost exactly how MPG began, but clearly Nathan is a lot smarter than I am and has built an amazing company in the same time it took me to get to this point. I feel quite disappointed when I think about it that way, but thankfully I don’t think it’s too late to do what I should have done a long time ago. I hope to meet Nathan one day, but even if I don’t, I consider him a mentor and his story provides validation that the MPG platform and community may be able to grow and be sustainable.

I think MPG/Engenuics Technologies can find similar success as SparkFun. We can do that without ever having to compete against SparkFun because what we do is unique enough. There might be a bit of overlap, but I’m always going to try to complement what SparkFun does rather than compete against it. We simply become another resource to feed the voracious and infinite appetite for information from students, hobbyists, and engineers. Win-win is always the way to go.

I decided I should grow the program instead of ending it, so I started Engenuics Technologies, which would be built on the decade of MPG experience plus the decade of embedded design experience I had from the industry. It seemed like a pretty solid foundation on which to start a company! Surely I could promote all of the content and find students of the same mindset I was in when I started MPG? They could lead the program at different universities and develop those infinitely valuable communication and leadership skills that MPG fosters, except they’d have the advantage of not having to put in hundreds of hours to write all of the material. Even if groups of people weren’t playing with MPG, individuals could make use of the technical resource on their own and we could have a solid online community. I also wanted to keep students engaged beyond the single year of their engineer degrees in which MPG existed.

CIRCUIT CELLAR: What other products/services does Engenuics Technologies provide?

JASON: I describe Engenuics Technologies as a four-tier company as there are three significant aspects of the business in addition to MPG. The main purpose of the company is to fill a gap in the industry for specific training in embedded systems. There is very little formal training to be found for low-to-mid-level embedded hardware and firmware development and quality/value is often hit or miss. From teaching for 10 years while being an embedded designer for the same amount of time, I felt like I had the right skills to create great training. I had already created a LabVIEW course that I delivered internally for a company while I worked there, and people were blown away by the quality and content. I saw a huge need to develop embedded-specific training to help new graduates transition to the industry as well as junior engineers who were lacking in some fundamental engineering knowledge.

We have an embedded boot camp course that is about 20% hardware and 80% firmware focused, which I think is essential for new engineering graduates getting into embedded design. Though the course is based specifically on a Cortex-M3 development board, we ensure that we focus on how to learn a processor so the knowledge can be applied to any platform.

Engenuics Technologies has several courses now and we continue to offer those periodically though never as often as we would like, as we’ve become too busy with the other parts of the company. We finally got an office last August with an onsite training room, which makes the logistics much easier, and we’re ramping up the frequency of the programs we offer.

CIRCUIT CELLAR: You earned your BSEE from the University of Calgary in 2002. Can you describe any of the projects you’ve worked while you were there?

JASON: The professors at the U of C were a phenomenal bunch and it was a privilege to get to know them and work with them during my undergraduate studies. I remain in contact with many of them, and several are very good friends. Aside from blinking some LEDs on breadboards, the first complicated device I built was an attempt at the IEEE Micromouse competition. That proved to be a little much and my robot never did do anything beyond go forward, sense a wall, and then back up.

While studying at the University of Calgary, some of Jason’s first embedded designs included a programmable phase-locked loop project, a robot built for an IEEE Micromouse competition, an MPG dev board, and a binary clock.

While studying at the University of Calgary, some of Jason’s first embedded designs included a programmable phase-locked loop project, a robot built for an IEEE Micromouse competition, an MPG dev board, and a binary clock.

I originally thought I would base MPG around building robots, but that proved impossible due to cost. Building a robot is still on my bucket list. I’ll likely get there once my two boys are old enough to want to build robots. I continue to fantasize about building an autonomous quadcopter that can deliver beer. I better get busy on that before its commonplace!

Our IEEE student branch had a Protel 99 SE license and somehow I learned how to design PCBs. The first board I designed was a binary clock that I still use. I then did a PIC programmer and later I built a combined development board and programmer for MPG.

I also designed the PCB for our fourth-year Capstone design project, which initially was a very boring implementation of a phase-locked loop, but became a lot more fun when I decided to make it programmable with a keypad and an LCD. I brought all these things to my BW Technologies job interview and proudly showed them off. For any students reading this, by the way, landing your first engineering job is probably 5% technical, 10% GPA, and 85% enthusiasm and demonstrated interest and achievement. It’s really boring to interview someone who has done nothing extracurricular.

CIRCUIT CELLAR: How long have you been designing embedded systems? When did you become interested?

JASON: My dad was a high school science teacher and my mom was a nurse, so I didn’t have a lot of technical influence growing up. I loved talking physics with my dad, and I’m one of the few engineers who can cook (thank you, mom).

Aside from really liking LEGO and dismantling anything electronic (without ever a hope of putting it back together but always wondering what all those funny looking components did), I barely demonstrated any interest in EE when I was young. But somehow I figured out in grade 12 that EE was probably what I should study at university.

I’m sure I still had visions of being a video game designer, but that nagging interest in learning what those funny components did steered me to EE instead of computer science. It wasn’t until my second year at university when someone gave me my first PIC microcontroller that I really knew that embedded was where I needed to be. That someone was a student named Sean Hum, a brilliant guy who is now an associate professor at the University of Toronto.

CIRCUIT CELLAR: Which new technologies excite you?

JASON: I particularly like the 2.4-GHz radio technologies that hold the potential to really make our environment interactive and intelligent. I think the world needs more intelligence to address the wasteful nature of what we have become whether it is by actively doing something like turning the lights or heat off when we’re not around, or by simply making us more aware of our surroundings. I love ANT+ and am just getting into BLE—obviously, smartphone integration will be critical.

I think technology will drive change in education and I hope to see (and perhaps be a driving force behind) a more cohesive existence between academics and the industry. I hope MPG becomes a model to the industry of what can be achieved with not a lot of financial resources, but has immense payback for employees who become mentors and students who can connect with the industry much earlier and thus get more from their degree programs and graduate with substantially higher capabilities.

You can read the entire interview in Circuit Cellar 289 (August 2014).

Q&A: Joe Grand – Engineer to the Core

From his grade-school Atari obsession and his teenage involvement in the L0pht Heavy Industries hacker group, to co-hosting Discovery Channel’s Prototype This! and starting his own company, Grand Idea Studio, Joe Grand has always maintained his passion for engineering. Joe and I recently discussed his journey and his lifelong love of all things engineering.—Nan Price, Associate Editor

NAN: Give us some background information. When and how did you discover electronics. What was your first project?


Joe Grand

JOE: I got involved with computers and electronics in 1982, when I was 7 years old. My first system was an Atari 400 computer, an Atari 810 floppy disk drive, and an Atari 830 acoustic coupler modem. I spent every waking hour playing computer games, trying to write my own programs, and connecting to local bulletin board systems. I was continually experimenting and questioning. I remember learning hexadecimal by poking around with a binary editor and figuring out how to replace names on game title screens with my own.
My brother, who is six years older than me, was also interested in computers and electronics. He would repair audio equipment, build telephone and computer gadgets, and disassemble broken electronics to scavenge them for parts. He had a cabinet that served as a junk bin for components and broken boards. When I did chores for him, like doing his laundry or cleaning his room, he’d let me pick something from the cabinet.

I was 13 years old when I hand-etched my first circuit board to make a “ring-busy device.” The device was simply a resistor across the tip and ring of the telephone line that had an RJ-11 plug for easy insertion/removal. It would make the telephone switch at the central office believe your phone was off the hook (thus, providing a busy signal to any incoming caller), but would still enable you to make outgoing calls. It was a fun, mischievous device, but also very practical to prevent annoying phone calls during dinner.

Right from the start, I had a strong emotional connection to all things electronic. I could just understand how technology was working even if I was unable to explain why. I knew early on that I wanted to be an electrical engineer. I wore this proudly on my sleeve, which didn’t help my ranking in the social hierarchy of elementary school!

NAN: What have been some of your influences?

JOE: In the early 1990s, when I was still a teenager, I joined a group called L0pht Heavy Industries (pronounced “loft” and spelled ell-zero-ph-t, The L0pht was a clubhouse for Boston-area hackers who had met on local bulletin board systems and it was one of the first publicly known “hackerspaces.” The L0pht simply started as a place to store computer equipment, tinker with technology, and hang out, but it ended up as seven close-knit friends changing the face of computer security vulnerability research and disclosure.

We would examine networks, software applications, and hardware products for security flaws. If we discovered a vulnerability, we would challenge the vendor to not only acknowledge the problem, but to fix it. This is now common practice, but back then, it was a feat practically unheard of.

I looked up to the other guys in the group. All were at least six years older than me and they became my mentors (whether they knew it or not) for nearly the next decade. They helped me to focus my energy on projects that would have positive impacts for other people. They also helped reinforce the hacker mindset—that is, not being afraid to try unconventional solutions to problems, pushing the limits of technology, being dedicated to learning through constant experimentation, and sharing my passion with others. Being involved in the L0pht was a very special time for me and shaped much of how I view the world.

NAN: You grew up and went to school in Boston. How did you end up in California?

JOE: Being in Boston for nearly 28 years left me with a lot of history (both good and bad). Everywhere I looked, I had a story, a feeling, or a connection to a time or event. I needed a clean slate. I had just left @stake, a computer security consulting firm that we started out of the L0pht, and my wife (girlfriend at the time) had just finished graduate school. She was also looking for new adventures, so we packed up our stuff and drove across the country not really knowing what we were going to do when we got to California. We lived in San Diego for a few years and ultimately settled in San Francisco when I started work on Discovery Channel’s Prototype This! television show.

San Francisco was a natural fit for us, and when the show ended, we decided to stay. Being close to Silicon Valley and its electronics stores (e.g., Jameco Electronics, WeirdStuff Warehouse, and HSC Electronic Supply) is quite useful, and I always get a thrill driving by the offices of chip vendors I use on a daily basis.

NAN: You started your own product design firm, Grand Idea Studio, in 2002. Tell us about the company.

JOE: Grand Idea Studio ( is a product design and licensing firm specializing in consumer/household devices and modules for electronics hobbyists. I started the company to create an environment that suited me best and would enable me to focus on what I loved to do. The majority of my work stems from ideas developed in-house or with my industrial design/mechanical engineering partners. I prefer to design simple, effective devices that serve a specific purpose. I’m all for using technology—but only where it’s needed—to make a product better.

Much of my time is spent building prototypes or proof-of-concepts of ideas (though many of those don’t ever see the light of day) that are sold and/or licensed to suitable partners. Some projects I’ll release as open source (usually through a Creative Commons Attribution license), so others can learn from my experiences and build upon my work to make something better.

I also teach a hardware hacking course at public and private events ( The course focuses on teaching board-level hardware hacking and reverse-engineering techniques and skills. It’s a combination of a lecture and hands-on exercises covering the hardware hacking process, proper use of tools and test measurement equipment, circuit board analysis and modification, embedded security, and common hardware attack vectors. The course concludes with a final hardware hacking challenge in which students must apply what they’ve learned to defeat the security mechanism of a custom circuit board. Design engineers and computer security researchers don’t often join forces. Being both, I feel like it’s part of my responsibility to help make that connection.

NAN: Tell us about your engineering experience prior to Grand Idea Studio.

JOE: My most relevant and memorable engineering experience was when I worked for Continuum (formerly Design Continuum,, a design and innovation consultancy based in West Newton, MA. I had worked on and off at the company during college and took a full-time engineering position in 1998. I was one of only two electrical engineers. We worked very closely with industrial designers, mechanical engineers, manufacturers, and clients to create innovative new products. Some key projects I contributed to were the A.T. Cross iPen (an early digital writing tablet) and the FluidSense FS-01 portable infusion pump (voted one of the best inventions of 2000 by Time magazine). It was during my time at Continuum that I learned about the product development and production manufacturing processes and sharpened my skills as an engineer.

NAN: Tell us about your experience working on Discovery Channel’s Prototype This! television show. Do you have a favorite project?


Prototype This! Giant Boxing Robot

JOE: Prototype This! (!) was a short-lived engineering entertainment show that followed the real-life design process of a unique prototype each episode. Although we only filmed for one season (comprising 13 episodes), the show gained a “cult” status of sorts among engineers and makers. It aired on Discovery Channel in the US in late 2008, but is now airing elsewhere throughout the world. The show is also available on Netflix, making it accessible to viewers who may have missed the show the first time around.

To be clear, I’m an engineer to the core, and I never had any intention of being in front of a camera as part of my job. But, the opportunity to show off engineering to the world in a way that was fun, entertaining, and somewhat educational seemed too good to pass up. Producing the show turned out to be a difficult and frustrating process, as we not only had to be on-screen television hosts trying to convey complex, technical builds in a way most viewers would understand, but we also had to actually engineer, design, build, and test the prototypes.

Prototype This! The PyroPack

We ended up building ridiculously crazy contraptions including “Mind Controlled Car” (Episode 1), giant 10’ “Boxing Robots” (Episode 2), and a “Traffic Busting Truck” that could elevate itself over other traffic and move in any direction (Episode 3). Each build had its own special flavor and design challenges and I actually enjoyed working on all of them. From an engineering point of view, I was most proud of the AirTrax control system (Episode 3), the PyroPack (Episode 6: “Robotic Firefighter Assistant”), and the underwater ROV controller (Episode 10: “Virtual Sea Adventure”). All of the documentation for my contributions to the builds, including schematics, source code, and development notes, is available at

Ultimately, the show proved to be unsustainable (from financial and time perspectives), but it was an unforgettable experience. The best thing is how the show continues to inspire future engineers. Nearly every day I receive e-mails from viewers asking for details about a particular build or what it takes to become an engineer, and I do my best to point them in the right direction.

NAN: You’ve designed dozens of things—from computer memory-imaging tools to children’s products to medical devices. Tell us about your design process. Do you have a favorite project?

JOE: I think my design process is very typical. I start by identifying and sourcing key components for the project. I’ll put together a preliminary block diagram and then build a proof-of-concept or prototype using a breadboard or PCB (depending on complexity and/or other constraints).

If the design is an embedded system that requires firmware, I’ll start writing it as soon as the prototype hardware is ready. This lets me validate that each hardware subsystem behaves as required and, if necessary, I can easily make changes to the design.

Once the hardware design has been sufficiently proven, I’ll move to a production design and form factor. Then, I’ll finish up the firmware, refine my documentation (which I work on throughout the process), and either release the design or move to production. If things go wrong, which they can sometimes do, then I may make multiple iterations of a design before it’s ready for production.

When I’m in the throes of the design process, I’m obsessed with the work. I think about it constantly—on my daily runs, in the shower, at bedtime, and sometimes while sleeping. I try to anticipate worst-case scenarios, component tolerances, failure modes, and how the end user will interact with the device (both correctly and incorrectly).

Every project I work on is currently my favorite and each project comes with its own challenges, successes, and failures. As soon as I’m done with one project, I’m looking for the next thing to do.

DEFCON 17 Badge

I’m particularly fond of my work on the DEF CON badges. Held every summer, DEF CON ( is the largest and oldest continuously running hacker event of its kind. It’s a mix of good guys, bad guys, government officials, and everyone in between, all having fun, sharing information, seeing old friends, and learning new things.

For five years (2006–2010) I had the honor of designing the official conference badges, which were artistic, fully functional electronic devices. I believe we were the first large-scale event to provide electronic badges to attendees. It changed what people have come to expect from a conference badge. The challenge was to create something that scrutinizing hackers would enjoy, appreciate, play with, and modify, while staying within the budget (around $10 per badge in 10,000-unit quantities).

The various badge designs have displayed custom scrolling text messages, turned off your television, transferred files over infrared, pulsed to music using fast Fourier transforms (FFTs), and provided USB functionality for computer control. They have incorporated technologies such as capacitive touch, RGB LEDs, microelectromechanical systems (MEMS) based microphones, “zero power” cholesteric LCDs, and microcontrollers ranging in size from tiny six-pin devices to powerful 64-pin behemoths. The physical PCBs used extremely complicated mechanical outlines, multiple layers of custom solder mask colors, and laser etching onto single-sided aluminum substrate PCBs.

DEFCON 18 Badge Backside

DEFCON 18 Badge close-up

Full details about the badges, along with schematics, source code, pictures, attendee hacks, and related articles, are available at (where x = 14, 15, 16, 17, 18).

NAN: Are you currently working on or planning any projects? Can you tell us about them?

JOE: There will (hopefully) never be a shortage of cool projects to work on. I like to keep multiple plates spinning at one time, though I can only talk about some of those plates.
At the recent 2013 DESIGN West conference, I released the JTAGulator (, which is an open-source, Parallax Propeller-based hardware tool that assists in identifying on-chip debug (OCD) and/or programming connections from test points, vias, or component pads on a target device. Discovering available interfaces is a common step in hardware hacking or reverse engineering, as they are usually left unprotected and can be used to extract memory or affect the state of a system on the fly.
A few similar tools exist, but they are either incomplete, closed source, or proof of concept. I wanted to create something that could be used in actual, real-world situations and that would help new people get involved in hardware hacking. The tool will also help to highlight the insecurity of leaving OCD interfaces enabled in production devices and hopefully serve as a catalyst for change in the engineering community (where convenience often trumps security). The JTAGulator currently supports JTAG and I will be making continued refinements to the firmware to add support for additional OCD protocols.

Last year, I finished up the Emic 2 Text-to-Speech module (, which has just started to appear in lots of interesting projects. The module is a self-contained, multi-language voice synthesizer that converts a stream of digital text into natural-sounding speech. It’s based on the Epson S1V30120 text-to-speech (TTS) IC, which uses the familiar DECtalk engine and is easy to interface to any microcontroller through a standard serial interface. Though embedded speech synthesis has been around for a while, there was no small form factor, low-cost solution readily available. So, I made one. A search for “Emic 2” on YouTube will result in various projects that use the module, including a tweet reader, a color-to-voice converter, a talking thermometer, an interaction with Apple’s Siri, and some singing demonstrations.

Some other projects I have planned include experimenting with PCB reverse-engineering techniques, hacking with a BeagleBone Black and OpenCV, and designing a new RFID system.

NAN: What do you consider to be the “next big thing” in the embedded design industry?

JOE: I’ve been increasingly concerned with the improper and (sometimes) socially unacceptable use of technology. From cameras at every street corner to mobile devices tracking your every move to Facebook and Google (among others) controlling your personal data, privacy has become something we’re slowly (and willingly?) losing. It’s a slippery slope that I don’t think many people will notice until it’s too late. The problem is largely driven by our society’s mass adoption of technology and taking that technology for granted. As an engineer and hacker, I strive to educate others about the unintended consequences of blindly using technology and hope it will make them more aware.

Member Profile: Tom Kibalo

Tom Kibalo

Location: Annapolis, MD

Education: BS, Electrical Engineering (City College, NY), and MS Electrical Engineering (University of Maryland)

Occupation: Tom is Principal Engineer of a large defense firm and CEO of KibaCorp, which he says is “dedicated to innovative educational technologies for the hobbyist, student, and practicing engineer.” He is also an adjunct faculty member at a local community college.

Member Status: Tom has been a subscriber for more than eight years.

Technical Interests: He is interested in robotics, embedded programming, microcontrollers, wireless applications, and engineering education.

Most Recent Embedded Tech-Related Acquisition: Tom’s most recent purchase was a Raspberry Pi with direct GPIO connections.

Current Projects: He is working on a battery-powered Wi-Fi sensor network that uses low-power Microchip Technology PIC32 components. (His project is shown in the photo.)

Thoughts on the Future of Embedded Technology: Tom thinks these are “exciting times where system-on-a-chip (SoC) technologies are extending the domain of embedded applications with Linux OS and a large base of language libraries.”

Q&A: Chris Paiano (Problem Solving & Design)

Chris Paiano is an Elko, NV-based problem engineer. His father introduced him to programming at an early age, and Chris has continued to team with his father to write software and firmware for some of his hardware designs. Chris has written dozens of unique application notes for the Cypress Semiconductor Programmable-System-on-Chip (PSoC) chipset. He is currently using PSoC in an innovative household project and dreams of finishing his concept for environmentally friendly electric/hybrid vehicle wheeldrive retrofit kits.

Chris Paiano working with his “office assistants” (bearded dragons)

You can read the complete interview in Circuit Cellar 272 March 2013.

NAN PRICE: Tell us a little about your background.

CHRIS PAIANO: I went to school in Orlando, FL, all the way through college at the University of Central Florida, where I obtained my bachelor’s degree in Computer Engineering.

I started at a very young age. My father always had an electronics workbench and I spent time there when I could. When I was 2 years old, he brought me home an Apple ][ with some floppy disks and told me there were games to be played—if I could only figure out how to make them work.

The Apple ][ was not the most user-friendly or intuitive computer system, by any means. In order to accomplish my important goal of playing video games, I had to learn how to work with the computer’s clunky command-line interface (CLI). Once I figured out how to make all the games work, I wanted to fully automate them so I didn’t have to go through all the manual steps to play them every time (also, so my friends could start them up without me). So, I spent much time developing automatic start-up scripts, from the Applesoft HELLO program to MS-DOS configuration start-up menus, supporting whatever memory management method was required to play certain games, along with icon-driven pre-Windows menu systems that made these early systems usable by my friends, family, and clients.

This evolved into more elaborate scripting and programming to fill the gaps where the tools I needed did not exist, so I had to create them. My possibilities really opened up when I began developing firmware to complement my father’s hardware designs.

NAN: Tell us about your company, Christopher Paiano Engineering (CpE).

CHRIS: I design and program prototypes for various clients. I provide them with ideas at various development stages, which I turn into something that they can mass produce. I’ve just redesigned my website (, by the way. It has a sleeker, simple interface and is easier to navigate now. No more Java menu with annoying sound effects!

NAN: Several of your projects are built around the Cypress Semiconductor programmable system-on-chip (PSoC). Is that your go-to chipset?

CHRIS: Yes, mainly because of how versatile and capable it is. It seems to be sufficient to take care of most any embedded task or set of tasks that come to mind.

For example, recently, the proprietor of a local game/tech/arcade business approached me to build a custom, inexpensive door chime. He wanted customers to hear random, recognizable portal sounds from popular video games whenever customers entered or exited his shop.

I started with an inexpensive motion sensor product from a local superstore. I added a Cypress CY8C27443 PSoC, as I have several lying around for general projects. I made a copy of my “Playing WAV Files with a PSoC” app note project to modify.

I added code to randomly cycle through available sound clips in the memory and I was able to provide 1.9805 s of audio at 8 kHz with the 16 KB of RAM available in this chip. The client was happy with this. He settled on two portal sounds (from The Legend of Zelda and Super Mario Brothers) and the chime has been in use for several months now. Customer feedback has been excellent. Everyone entering the place immediately recognizes the sounds and loves it!

NAN: You’ve written more than 30 application notes for the Cypress chipset, including PongSoC and the Video RTA. Can you explain the process?

CHRIS: Sometimes Cypress would post bounties for app notes that they’d like to see written on a certain topic or capability. Other times, I’d have an interesting personal project for which I decided to utilize a PSoC. I would then decide it might make a good app note, so I’d write it up and submit it. Either way, I’d usually develop the project side-by-side with my father. (We make an excellent hardware/software team.) I work out whatever firmware and PC/smartphone apps may be necessary, and he builds the PSoC circuit board with which to test. Then, I document it all, arrange it, and edit it into an app note (or, in some cases, an article).

Sometimes a project is just too complex to squeeze into a single PSoC’s resources and the simplest solution is to just add another PSoC. Communication between PSoCs can be quick and easy to implement, so distributing tasks and maintaining synchronization is not too difficult. This was the solution for the video real-time analyzer (RTA) app note where, realistically, there were only enough internal analog resources to provide three filters in each PSoC. With the Video RTA, one just adds as many PSoCs to the bus as is necessary to achieve the desired analyzer resolution.

The PongSoC was a fun one! Once I learned it was possible to combine some internal PSoC modules and algorithms to generate a stable composite video signal, I immediately decided I wanted to try and utilize this new capability to recreate a Pong-like embedded game-on-a-chip. I could already generate sound effects and read potentiometers for paddle inputs, I just needed to work it all out. I had a great time doing so, testing it with friends and playing with the variables to tweak the gameplay, and so forth.

Additionally, all 40 of my PSoC application notes are now available in some capacity on my updated website, as Cypress does not actively market the older PSoC families that many of my projects utilized in the past. I get enough e-mail requests for source code and documentation from this collection, so I have just gone ahead and taken the time to restore as many as I could find from my archives to the new website.

NAN: Your two-part article series “PSoC Design Techniques” describes how to build an eight-channel mixer and how DSP effects and a user interface can be added to it (Circuit Cellar 216–217, 2008). Describe the design and why you chose this design concept.

CHRIS: This was a great challenge. In a chip that traditionally would only allow for four full audio pathways in the provided analog resources (four PGA modules utilizing the normal I/O paths provided by PSoC Designer), we managed to figure out a way to utilize the remaining switched-capacitor blocks to act as signal mixers and gain stages with enough live reconfigurable resources to add potentiometers to control volume for each channel. Since there was still plenty of code space, I went ahead and added some DSP effects (reverb and pitch shift) along with a voice menu and flash-settings memory.

I really wanted to showcase what efficient design and algorithms could accomplish in a single piece of silicon, and I’m quite pleased with the way this project turned out. I still use the resulting device on my workbench and in my setups. It comes in handy sometimes. I have not updated it at all. I’ve been using it as is and it is still available for purchase on my website for anyone interested in experimenting with one.

NAN: Are you currently working on or planning any microprocessor-based projects?

CHRIS: Currently, I’m working on a PSoC solution for my broken dishwasher.

Chris Paiano is developing a PSoC solution for a broken dishwasher. In addition to the fix, he plans to make it smartphone-controllable.

The control module on this appliance has failed, so I am wiring it into a PSoC to make it work again as well as add some new capabilities (such as keeping a wash/rinse/door open log so it can tell when the dishes contained within it are clean or dirty, and adding a Bluetooth module so I can check the status and control/program the appliance from my smartphone).

This is the type of personal project I like to work on in my free time. It also might make a good app note or article in the future, as it involves an Android application and Bluetooth communication. It also increases my capabilities, if I have to figure out anything new. And that is always good.

I am almost ready to hook it up to the dishwasher, let it try running through the cycles, and hope I don’t flood my house in the process. Ah, the pure excitement of engineering!

The entire interview is available in Circuit Cellar 272 March 2013.