The Future of Monolithically Integrated LED Arrays

LEDs are ubiquitous in our electronic lives. They are widely used in notification lighting, flash photography, and light bulbs, to name a few. For displays, LEDs have been commercialized as backlights in televisions and projectors. However, their use in image formation has been limited.

A prototype emissive LED display chip is shown. The chip includes an emissive compass pattern ready to embed into new applications.

A prototype emissive LED display chip is shown. The chip includes an emissive compass pattern ready to embed into new applications.

The developing arena of monolithically integrated LED arrays, which involves fabricating millions of LEDs with corresponding transistors on a single chip, provides many new applications not possible with current technologies, as the LEDs can simultaneously act as the backlight and the image source.

The common method of creating images is to first generate light (using LEDs) and then filter that light using a spatial light modulator. The filter could be an LCD, liquid crystal on silicon (LCoS), or a digital micromirror device (DMD) such as a Digital Light Processing (DLP) projector. The filtering processes cause significant loss of light in these systems, despite the brightness available from LEDs. For example, a typical LCD uses only 1% to 5% of the light generated.

Two pieces are essential to a display: a light source and a light controller. In most display technologies, the light source and light control functionalities are served by two separate components (e.g., an LED backlight and an LCD). However, in emissive displays, both functionalities are combined into a single component, enabling light to be directly controlled without the inherent inefficiencies and losses associated with filtering. Because each light-emitting pixel is individually controlled, light can be generated and emitted exactly where and when needed.

Emissive displays have been developed in all sizes. Very-large-format “Times Square” and stadium displays are powered by large arrays of individual conventional LEDs, while new organic LED (OLED) materials are found in televisions, mobile phones, and other micro-size applications. However, there is still a void. Emissive “Times Square” displays cannot be scaled to small sizes and emissive OLEDs do not have the brightness available for outdoor environments and newer envisioned applications. An emissive display with high brightness but in a micro format is required for applications such as embedded cell phone projectors or displays on see-through glasses.

We know that optimization by the entire LED industry has made LEDs the brightest controllable light source available. We also know that a display requires a light source and a method of controlling the light. So, why not make an array of LEDs and control individual LEDs with a matching array of transistors?

The marrying of LED materials (light source) to transistors (light control) has long been researched. There are three approaches to this problem: fabricate the LEDs and transistors separately, then bond them together; fabricate transistors first, then integrate LEDs on top; and fabricate LEDs first, then integrate transistors on top. The first method is not monolithic. Two fabricated chips are electrically and mechanically bonded, limiting integration density and thus final display resolutions. The second method, starting with transistors and then growing LEDs, offers some advantages in monolithic (single-wafer) processing, but growth of high-quality, high-efficiency LEDs on transistors has proven difficult.

My start-up company, Lumiode (, is developing the third method, starting with optimized LEDs and then fabricating silicon transistors on top. This leverages existing LED materials for efficient light output. It also requires careful fabrication of the integrated transistor layer as to not damage the underlying LED structures. The core technology uses a laser method to provide extremely local high temperatures to the silicon while preventing thermal damage to the LED. This overcomes typical process incompatibilities, which have previously held back development of monolithically integrated LED arrays. In the end, there is an array of LEDs (light source) and corresponding transistors to control each individual LED (light control), which can reach the brightness and density requirements of future microdisplays.

Regardless of the specific integration method employed, a monolithically integrated LED and transistor structure creates a new range of applications requiring higher efficiency and brightness. The brightness available from integrated LED arrays can enable projection on truly see-through glass, even in outdoor daylight environments. The efficiency of an emissive display enables extended battery lifetimes and device portability. Perhaps we can soon achieve the types of displays dreamed up in movies.

The Future of Small Radar Technology

Directing the limited resources of Fighter Command to intercept a fleet of Luftwaffe bombers en route to London or accurately engaging the Imperial Navy at 18,000 yards in the dead of night. This was our grandfather’s radar, the technology that evened the odds in World War II.

This is the combat information center aboard a World War II destroyer with two radar displays.

This is the combat information center aboard a World War II destroyer with two radar displays.

Today there is an insatiable demand for short-range sensors (i.e., small radar technology)—from autonomous vehicles to gaming consoles and consumer devices. State-of-the-art sensors that can provide full 3-D mapping of a small-target scenes include laser radar and time-of-flight (ToF) cameras. Less expensive and less accurate acoustic and infrared devices sense proximity and coarse angle of arrival. The one sensor often overlooked by the both the DIY and professional designer is radar.

However, some are beginning to apply small radar technology to solve the world’s problems. Here are specific examples:

Autonomous vehicles: In 2007, the General Motors and Carnegie Mellon University Tartan Racing team won the Defense Advanced Research Projects Agency (DARPA) Urban Challenge, where autonomous vehicles had to drive through a city in the shortest possible time period. Numerous small radar devices aided in their real-time decision making. Small radar devices will be a key enabling technology for autonomous vehicles—from self-driving automobiles to unmanned aerial drones.

Consumer products: Recently, Massachusetts Institute of Technology (MIT) researchers developed a radar sensor for gaming systems, shown to be capable of detecting gestures and other complex movements inside a room and through interior walls. Expect small radar devices to play a key role in enabling user interface on gaming consoles to smartphones.

The Internet of Things (IoT): Fybr is a technology company that uses small radar sensors to detect the presence of parked automobiles, creating the most accurate parking detection system in the world for smart cities to manage parking and traffic congestion in real time. Small radar sensors will enable the IoT by providing accurate intelligence to data aggregators.

Automotive: Small radar devices are found in mid- to high-priced automobiles in automated cruise control, blind-spot detection, and parking aids. Small radar devices will soon play a key role in automatic braking, obstacle-avoidance systems, and eventually self-driving automobiles, greatly increasing passenger safety.

Through-Wall Imaging: Advances in small radar have numerous possible military applications, including recent MIT work on through-wall imaging of human targets through solid concrete walls. Expect more military uses of small radar technology.

What is taking so long? A tremendous knowledge gap exists between writing the application and emitting, then detecting, scattered microwave fields and understanding the result. Radar was originally developed by physicists who had a deep understanding of electromagnetics and were interested in the theory of microwave propagation and scattering. They created everything from scratch, from antennas to specialized vacuum tubes.

Microwave tube development, for example, required a working knowledge of particle physics. Due to this legacy, radar textbooks are often intensely theoretical. Furthermore, microwave components were very expensive—handmade and gold-plated. Radar was primarily developed by governments and the military, which made high-dollar investments for national security.

Small radar devices such as the RFBeam Microwave K-LC1a radio transceiver cost less than $10 when purchased in quantity.

Small radar devices such as the RFBeam Microwave K-LC1a radio transceiver cost less than $10 when purchased in quantity.

It’s time we make radar a viable option for DIY projects and consumer devices by developing low-cost, easy-to-use, capable technology and bridging the knowledge gap!
Today you can buy small radar sensors for less than $10. Couple this with learning practical radar processing methods, and you can solve a critical sensing problem for your project.

Learn by doing. I created the MIT short-course “Build a Small Radar Sensor,” where students learn about radar by building a device from scratch. Those interested can take the online course for free through MIT Opencourseware or enroll in the five-day MIT Professional Education course.

Dive deeper. My soon-to-be published multimedia book, Small and Short-Range Radar Systems, explains the principles and building of numerous small radar devices and then demonstrates them so readers at all levels can create their own radar devices or learn how to use data from off-the-shelf radar sensors.

This is just the beginning. Soon small radar sensors will be everywhere.

Low-Cost SBCs Could Revolutionize Robotics Education

For my entire life, my mother has been a technology trainer for various educational institutions, so it’s probably no surprise that I ended up as an engineer with a passion for STEM education. When I heard about the Raspberry Pi, a diminutive $25 computer, my thoughts immediately turned to creating low-cost mobile computing labs. These labs could be easily and quickly loaded with a variety of programming environments, walking students through a step-by-step curriculum to teach them about computer hardware and software.

However, my time in the robotics field has made me realize that this endeavor could be so much more than a traditional computer lab. By adding actuators and sensors, these low-cost SBCs could become fully fledged robotic platforms. Leveraging the common I2C protocol, adding chains of these sensors would be incredibly easy. The SBCs could even be paired with microcontrollers to add more functionality and introduce students to embedded design.

rover_webThere are many ways to introduce students to programming robot-computers, but I believe that a web-based interface is ideal. By setting up each computer as a web server, students can easily access the interface for their robot directly though the computer itself, or remotely from any web-enabled device (e.g., a smartphone or tablet). Through a web browser, these devices provide a uniform interface for remote control and even programming robotic platforms.

A server-side language (e.g., Python or PHP) can handle direct serial/I2C communications with actuators and sensors. It can also wrap more complicated robotic concepts into easily accessible functions. For example, the server-side language could handle PID and odometry control for a small rover, then provide the user functions such as “right, “left,“ and “forward“ to move the robot. These functions could be accessed through an AJAX interface directly controlled through a web browser, enabling the robot to perform simple tasks.

This web-based approach is great for an educational environment, as students can systematically pull back programming layers to learn more. Beginning students would be able to string preprogrammed movements together to make the robot perform simple tasks. Each movement could then be dissected into more basic commands, teaching students how to make their own movements by combining, rearranging, and altering these commands.

By adding more complex commands, students can even introduce autonomous behaviors into their robotic platforms. Eventually, students can be given access to the HTML user interfaces and begin to alter and customize the user interface. This small superficial step can give students insight into what they can do, spurring them ahead into the next phase.
Students can start as end users of this robotic framework, but can eventually graduate to become its developers. By mapping different commands to different functions in the server side code, students can begin to understand the links between the web interface and the code that runs it.

Kyle Granat

Kyle Granat, who wrote this essay for Circuit Cellar,  is a hardware engineer at Trossen Robotics, headquarted in Downers Grove, IL. Kyle graduated from Purdue University with a degree in Computer Engineering. Kyle, who lives in Valparaiso, IN, specializes in embedded system design and is dedicated to STEM education.

Students will delve deeper into the server-side code, eventually directly controlling actuators and sensors. Once students begin to understand the electronics at a much more basic level, they will be able to improve this robotic infrastructure by adding more features and languages. While the Raspberry Pi is one of today’s more popular SBCs, a variety of SBCs (e.g., the BeagleBone and the pcDuino) lend themselves nicely to building educational robotic platforms. As the cost of these platforms decreases, it becomes even more feasible for advanced students to recreate the experience on many platforms.

We’re already seeing web-based interfaces (e.g., ArduinoPi and WebIOPi) lay down the beginnings of a web-based framework to interact with hardware on SBCs. As these frameworks evolve, and as the costs of hardware drops even further, I’m confident we’ll see educational robotic platforms built by the open-source community.

CC281: Overcome Fear of Ethernet on an FPGA

As its name suggests, the appeal of an FPGA is that it is fully programmable. Instead of writing software, you design hardware blocks to quickly do what’s required of a digital design. This also enables you to reprogram an FPGA product in the field to fix problems “on the fly.”

But what if “you” are an individual electronics DIYer rather than an industrial designer? DIYers can find FPGAs daunting.

Issue281The December issue of Circuit Cellar issue should offer reassurance, at least on the topic of “UDP Streaming on an FPGA.” That’s the focus of Steffen Mauch’s article for our Programmable Logic issue (p. 20).

Ethernet on an FPGA has several applications. For example, it can be used to stream measured signals to a computer for analysis or to connect a camera (via Camera Link) to an FPGA to transmit images to a computer.

Nonetheless, Mauch says, “most novices who start to develop FPGA solutions are afraid to use Ethernet or DDR-SDRAM on their boards because they fear the resulting complexity.” Also, DIYers don’t have the necessary IP core licenses, which are costly and often carry restrictions.

Mauch’s UDP monitor project avoids such costs and restrictions by using a free implementation of an Ethernet-streaming device based on a Xilinx Spartan-6 LX FPGA. His article explains how to use OpenCores’s open-source tri-mode MAC implementation and stream UDP packets with VHDL over Ethernet.

Mauch is not the only writer offering insights into FPGAs. For more advanced FPGA enthusiasts, columnist Colin O’Flynn discusses hardware co-simulation (HCS), which enables the software simulation of a design to be offloaded to an FPGA. This approach significantly shortens the time needed for adequate simulation of a new product and ensures that a design is actually working in hardware (p. 52).

This Circuit Cellar issue offers a number of interesting topics in addition to programmable logic. For example, you’ll find a comprehensive overview of the latest in memory technologies, advice on choosing a flash file system for your embedded Linux system, a comparison of amplifier classes, and much more.

Mary Wilson

Member Profile: Scott Weber

Scott Weber

Scott Weber

Arlington, Texas, USA

Scott said he started his Circuit Cellar subscription late in the last century. He chose the magazine because it had the right mix of MCU programming and electronics.

He has always enjoyed mixing discrete electronic projects with MCUs. In the early 1980s, he built a MCU board based on an RCA CDP1802 with wirewrap and programmed it with eight switches and a load button.

Back in the 1990s, Scott purchased a Microchip Technology PICStart Plus. “I was thrilled at how powerful and comprehensive the chip and tools were compared to the i8085 and CDP1802 devices I tinkered with years before,” he said.

Scott said he recently treated himself to a brand-new Fluke 77-IV multimeter.

Scott is building devices that can communicate through USB to MS Windows programs. “I don’t have in mind any specific system to control, it is something to learn and have fun with,” he said. “This means learning not only an embedded USB software framework, but also Microsoft Windows device drivers.”

“Embedded devices are popping up everywhere—in places most people don’t even realize they are being used. It’s fun discovering where they are being applied. It is so much easier to change the microcode of an MCU or FPGA as the unit is coming off the assembly line than it is to rewire a complex circuit design,” Scott said.

“I also like Member Profile Joe Pfeiffer’s final comment in Circuit Cellar 276: Surface-mount and ASIC devices are making a ‘barrier to entry’ for the hobbyist. You can’t breadboard those things! I gotta learn a good way to make my own PCBs!”

Natural Human-Computer Interaction

Recent innovations in both hardware and software have brought on a new wave of interaction techniques that depart from mice and keyboards. The widespread adoption of smartphones and tablets with capacitive touchscreens shows people’s preference to directly manipulate virtual objects with their hands.

Going beyond touch-only interaction, the Microsoft Kinect sensor enables users to play

This shows the hand tracking result from Kinect data. The red regions are our tracking results and the green lines are the skeleton tracking results from the Kinect SDK (based on data from the ChAirGest corpus:

This shows the hand tracking result from Kinect data. The red regions are our tracking results and the green lines are the skeleton tracking results from the Kinect SDK (based on data from the ChAirGest corpus:

games with their entire body. More recently, Leap Motion’s new compact sensor, consisting of two cameras and three infrared LEDs, has opened up the possibility of accurate fingertip tracking. With Project Glass, Google is pioneering new technology in the wearable human-computer interface. Other new additions to wearable technology include Samsung’s Galaxy Gear Smartwatch and Apple’s rumored iWatch.

A natural interface reduces the learning curve, or the amount of time and energy a person requires to complete a particular task. Instead of a user learning to communicate with a machine through a programming language, the machine is now learning to understand the user.

Hardware advancements have led to our clunky computer boxes becoming miniaturized, stylish sci-fi-like phones and watches. Along with these shrinking computers come ever-smaller sensors that enable a once keyboard-constrained computer to listen, see, and feel. These developments pave the way to natural human-computer interfaces.
If sensors are like eyes and ears, software would be analogous to our brains.

Understanding human speech and gestures in real time is a challenging task for natural human-computer interaction. At a higher level, both speech and gesture recognition require similar processing pipelines that include data streaming from sensors, feature extraction, and pattern recognition of a time series of feature vectors. One of the main differences between the two is feature representation because speech involves audio data while gestures involve video data.

For gesture recognition, the first main step is locating the user’s hand. Popular libraries for doing this include Microsoft’s Kinect SDK or PrimeSense’s NITE library. However, these libraries only give the coordinates of the hands as points, so the actual hand shapes cannot be evaluated.

Fingertip tracking using a Kinect sensor. The green dots are the tracked fingertips.

Our team at the Massachusetts Institute of Technology (MIT) Computer Science and Artificial Intelligence Laboratory has developed methods that use a combination of skin-color and motion detection to compute a probability map of gesture salience location. The gesture salience computation takes into consideration the amount of movement and the closeness of movement to the observer (i.e., the sensor).

We can use the probability map to find the most likely area of the gesturing hands. For each time frame, after extracting the depth data for the entire hand, we compute a histogram of oriented gradients to represent the hand shape as a more compact feature descriptor. The final feature vector for a time frame includes 3-D position, velocity, and hand acceleration as well as the hand shape descriptor. We also apply principal component analysis to reduce the feature vector’s final dimension.

A 3-D model of pointing gestures using a Kinect sensor. The top left video shows background subtraction, arm segmentation, and fingertip tracking. The top right video shows the raw depth-mapped data. The bottom left video shows the 3D model with the white plane as the tabletop, the green line as the arm, and the small red dot as the fingertip.

The next step in the gesture-recognition pipeline is to classify the feature vector sequence into different gestures. Many machine-learning methods have been used to solve this problem. A popular one is called the hidden Markov model (HMM), which is commonly used to model sequence data. It was earlier used in speech recognition with great success.

There are two steps in gesture classification. First, we need to obtain training data to learn the models for different gestures. Then, during recognition, we find the most likely model that can produce the given observed feature vectors. New developments in the area involve some variations in the HMM, such as using hierarchical HMM for real-time inference or using discriminative training to increase the recognition accuracy.

Ying Yin

Ying Yin is a PhD candidate and a Research Assistant at the Massachusetts Institute of Technology (MIT) Computer Science and Artificial Intelligence Laboratory. Originally from Suzhou, China, Ying received her BASc in Computer Engineering from the University of British Columbia in Vancouver, Canada, in 2008 and an MS in Computer Science from MIT in 2010. Her research focuses on applying machine learning and computer vision methods to multimodal human-computer interaction. Ying is also interested in web and mobile application development. She has won awards in web and mobile programming competitions at MIT.

Currently, the newest development in speech recognition at the industry scale is a method called deep learning. Earlier machine-learning methods require careful selection of feature vectors. The goal of deep learning is automatic discovery of powerful features from raw input data. So far, it has shown promising results in speech recognition. It can possibly be applied to gesture recognition to see whether it can further improve accuracy.

As component form factors shrink, sensor resolutions grow, and recognition algorithms become more accurate, natural human-computer interaction will become more and more ubiquitous in our everyday life.

3-D Printing with Liquid Metals

by Collin Ladd and Michael Dickey

Our research group at North Carolina State University has been studying new ways to use simple processes to print liquid metals into 3-D shapes at room temperature. 3-D printing is gaining popularity because of the ability to quickly go from concept to reality to design, replicate, or create objects. For example, it is now possible to draw an object on a computer or scan a physical object into software and have a highly detailed replica within a few hours.

3-D printing with liquid metals: a line of dollsMost 3-D printers currently pattern plastics, but printing metal objects is of particular interest because of metal’s physical strength and electrical conductivity. Because of the difficulty involved with metal printing, it is considered one of the “frontiers” of 3-D printing.
There are several approaches for 3-D printing of metals, but they all have limitations, including high temperatures (making it harder to co-print with other materials) and prohibitively expensive equipment. The most popular approach to printing metals is to use lasers or electron beams to sinter fine metal powders together at elevated temperatures, one layer at a time, to form solid metal parts.

Our approach uses a simple method to enable direct printing of liquid metals at room temperature. We print liquid metal alloys primarily composed of gallium. These alloys have metallic conductivity and a viscosity similar to water. Unlike mercury, gallium is not considered toxic nor does it evaporate. We extrude this metal from a nozzle to create droplets that can be stacked to form 3-D structures. Normally, two droplets of liquid (e.g., water) merge together into a single drop if stacked on each other. However, these metal droplets do not succumb to surface-tension effects because the metal rapidly forms a solid oxide “skin” on its surface that mechanically stabilizes the printed structures. This skin also makes it possible to extrude wires or metal fibers.

This printing process is important for two reasons. First, it enables the printing of metallic structures at room temperature using a process that is compatible with other printed materials (e.g., plastics). Second, it results in metal structures that can be used for flexible and stretchable electronics.


Stretchable electronics are motivated by the new applications that emerge by building electronic functionality on deformable substrates. It may enable new wearable sensors and textiles that deform naturally with the human body, or even an elastic array of embedded sensors that could serve as a substitute for skin on a prosthetic or robot-controlled fingertip. Unlike the bendable polyimide-based circuits commonly seen on a ribbon cable or inside a digital camera, stretchable electronics require more mechanical robustness, which may involve the ability to deform like a rubber band. However, a stretchable device need not be 100% elastic. Solid components embedded in a substrate (e.g., silicone) can be incorporated into a stretchable device if the connections between them can adequately deform.

Using our approach, we can direct print freestanding wire bonds or circuit traces to directly connect components—without etching or solder—at room temperature. Encasing these structures in polymer enables these interconnects to be stretched tenfold without losing electrical conductivity. Liquid metal wires also have been shown to be self-healing, even after being completely severed. Our group has demonstrated several applications of the liquid metal in soft, stretchable components including deformable antennas, soft-memory devices, ultra-stretchable wires, and soft optical components.

Although our approach is promising, there are some notable limitations. Gallium alloys are expensive and the price is expected to rise due to gallium’s expanding industrial use. Nevertheless, it is possible to print microscale structures without using much volume, which helps keep the cost down per component. Liquid metal structures must also be encased in a polymer substrate because they are not strong enough to stand by themselves for rugged applications.

Our current work is focused on optimizing this process and exploring new material possibilities for 3-D printing. We hope advancements will enable users to print new embedded electronic components that were previously challenging or impossible to construct using a 3-D printer.

Collin Ladd (  is pursuing a career in medicine at the Medical University of South Carolina in Charleston, SC. Since 2009, he has been the primary researcher for the 3-D printed liquid metals project at The Dickey Group, which is headed by Michael Dickey. Collin’s interests include circuit board design and robotics. He has been an avid electronics hobbyist since high school.

Collin Ladd ( is pursuing a career in medicine at the Medical University of South Carolina in Charleston, SC. Since 2009, he has been the primary researcher for the 3-D printed liquid metals project at The Dickey Group, which is headed by Michael Dickey. Collin’s interests include circuit board design and robotics. He has been an avid electronics hobbyist since high school.

Michael Dickey ( is an associate professor at the North Carolina State University Department of Chemical and Biomolecular Engineering. His research includes studying soft materials, thin films and interfaces, and unconventional nanofabrication techniques. His research group’s projects include stretchable electronics, patterning gels, and self-folding sheets.

Michael Dickey ( is an associate professor at the North Carolina State University Department of Chemical and Biomolecular Engineering. His research includes studying soft materials, thin films and interfaces, and unconventional nanofabrication techniques. His research group’s projects include stretchable electronics, patterning gels, and self-folding sheets.




Q&A: Jeremy Blum, Electrical Engineer, Entrepreneur, Author

Jeremy Blum

Jeremy Blum

Jeremy Blum, 23, has always been a self-proclaimed tinkerer. From Legos to 3-D printers, he has enjoyed learning about engineering both in and out of the classroom. A recent Cornell University College of Engineering graduate, Jeremy has written a book, started his own company, and traveled far to teach children about engineering and sustainable design. Jeremy, who lives in San Francisco, CA, is now working on Google’s Project Glass.—Nan Price, Associate Editor

NAN: When did you start working with electronics?

JEREMY: I’ve been tinkering, in some form or another, ever since I figured out how to use my opposable thumbs. Admittedly, it wasn’t electronics from the offset. As with most engineers, I started with Legos. I quickly progressed to woodworking and I constructed several pieces of furniture over the course of a few years. It was only around the start of my high school career that I realized the extent to which I could express my creativity with electronics and software. I thrust myself into the (expensive) hobby of computer building and even built an online community around it. I financed my hobby through my two companies, which offered computer repair services and video production services. After working exclusively with computer hardware for a few years, I began to dive deeper into analog circuits, robotics, microcontrollers, and more.

NAN: Tell us about some of your early, pre-college projects.

JEREMY: My most complex early project was the novel prosthetic hand I developed in high school. The project was a finalist in the prestigious Intel Science Talent Search. I also did a variety of robotics and custom-computer builds. The summer before starting college, my friends and I built a robot capable of playing “Guitar Hero” with nearly 100% accuracy. That was my first foray into circuit board design and parallel programming. My most ridiculous computer project was a mineral oil-cooled computer. We submerged an entire computer in a fish tank filled with mineral oil (it was actually a lot of baby oil, but they are basically the same thing).

DeepNote Guitar Hero Robot

DeepNote Guitar Hero Robot

Mineral Oil-Cooled Computer

Mineral Oil-Cooled Computer

NAN: You’re a recent Cornell University College of Engineering graduate. While you were there, you co-founded Cornell’s PopShop. Tell us about the workspace. Can you describe some PopShop projects?

Cornell University's PopShop

Cornell University’s PopShop

JEREMY: I recently received my Master’s degree in Electrical and Computer Engineering from Cornell University, where I previously received my BS in the same field. During my time at Cornell, my peers and I took it upon ourselves to completely retool the entrepreneurial climate at Cornell. The PopShop, a co-working space that we formed a few steps off Cornell’s main campus, was our primary means of doing this. We wanted to create a collaborative space where students could come to explore their own ideas, learn what other entrepreneurial students were working on, and get involved themselves.

The PopShop is open to all Cornell students. I frequently hosted events there designed to get more students inspired about pursuing their own ideas. Common occurrences included peer office hours, hack-a-thons, speed networking sessions, 3-D printing workshops, and guest talks from seasoned venture capitalists.

Student startups that work (or have worked) out of the PopShop co-working space include clothing companies, financing companies, hardware startups, and more. Some specific companies include Rosie, SPLAT, LibeTech (mine), SUNN (also mine), Bora Wear, Yorango, Party Headphones, and CoVenture.

NAN: Give us a little background information about Cornell University Sustainable Design (CUSD). Why did you start the group? What types of CUSD projects were you involved with?

CUSD11JEREMY: When I first arrived at Cornell my freshman year, I knew right away that I wanted to join a research lab, and that I wanted to join a project team (knowing that I learn best in hands-on environments instead of in the classroom). I joined the Cornell Solar Decathlon Team, a very large group of mostly engineers and architects who were building a solar-powered home to enter in the biannual solar decathlon competition orchestrated by the Department of Energy.

By the end of my freshman year, I was the youngest team leader in the organization.  After competing in the 2009 decathlon, I took over as chief director of the team and worked with my peers to re-form the organization into Cornell University Sustainable Design (CUSD), with the goal of building a more interdisciplinary team, with far-reaching impacts.


Under my leadership, CUSD built a passive schoolhouse in South Africa (which has received numerous international awards), constructed a sustainable community in Nicaragua, has been the only student group tasked with consulting on sustainable design constraints for Cornell’s new Tech Campus in New York City, partnered with nonprofits to build affordable homes in upstate New York, has taught workshops in museums and school, contributed to the design of new sustainable buildings on Cornell’s Ithaca campus, and led a cross-country bus tour to teach engineering and sustainability concepts at K–12 schools across America. The group is now comprised of students from more than 25 different majors with dozens of advisors and several simultaneous projects. The new team leaders are making it better every day. My current startup, SUNN, spun out of an EPA grant that CUSD won.

CUSD7NAN: You spent two years working at MakerBot Industries, where you designed electronics for a 3-D printer and a 3-D scanner. Any highlights from working on those projects?

JEREMY: I had a tremendous opportunity to learn and grow while at MakerBot. When I joined, I was one of about two dozen total employees. Though I switched back and forth between consulting and full-time/part-time roles while class was in session, by the time I stopped working with MakerBot (in January 2013), the company had grown to more than 200 people. It was very exciting to be a part of that.

I designed all of the electronics for the original MakerBot Replicator. This constituted a complete redesign from the previous electronics that had been used on the second generation MakerBot 3-D printer. The knowledge I gained from doing this (e.g., PCB design, part sourcing, DFM, etc.) drastically outweighed much of what I had learned in school up to that point. I can’t say much about the 3-D scanner (the MakerBot Digitizer), as it has been announced, but not released (yet).

The last project I worked on before leaving MakerBot was designing the first working prototype of the Digitizer electronics and firmware. These components comprised the demo that was unveiled at SXSW this past April. This was a great opportunity to apply lessons learned from working on the Replicator electronics and find ways in which my personal design process and testing techniques could be improved. I frequently use my MakerBot printers to produce custom mechanical enclosures that complement the open-source electronics projects I’ve released.

NAN: Tell us about your company, Blum Idea Labs. What types of projects are you working on?

JEREMY: Blum Idea Labs is the entity I use to brand all my content and consulting services. I primarily use it as an outlet to facilitate working with educational organizations. For example, the St. Louis Hacker Scouts, the African TAHMO Sensor Workshop, and several other international organizations use a “Blum Idea Labs Arduino curriculum.” Most of my open-source projects, including my tutorials, are licensed via Blum Idea Labs. You can find all of them on my blog ( I occasionally offer private design consulting through Blum Idea Labs, though I obviously can’t discuss work I do for clients.

NAN: Tell us about the blog you write for element14.

JEREMY: I generally use my personal blog to write about projects that I’ve personally been working on.  However, when I want to talk about more general engineering topics (e.g., sustainability, engineering education, etc.), I post them on my element14 blog. I have a great working relationship with element14. It has sponsored the production of all my Arduino Tutorials and also provided complete parts kits for my book. We cross-promote each-other’s content in a mutually beneficial fashion that also ensures that the community gets better access to useful engineering content.

NAN: You recently wrote Exploring Arduino: Tools and Techniques for Engineering Wizardry. Do you consider this book introductory or is it written for the more experienced engineer?

JEREMY: As with all the video and written content that I produce on my website and on YouTube, I tried really hard to make this book useful and accessible to both engineering veterans and newbies. The book builds on itself and provides tons of optional excerpts that dive into greater technical detail for those who truly want to grasp the physics and programming concepts behind what I teach in the book. I’ve already had readers ranging from teenagers to senior citizens comment on the applicability of the book to their varying degrees of expertise. The Amazon reviews tell a similar story. I supplemented the book with a lot of free digital content including videos, part descriptions, and open-source code on the book website.

NAN: What can readers expect to learn from the book?

JEREMY: I wrote the book to serve as an engineering introduction and as an idea toolbox for those wanting to dive into concepts in electrical engineering, computer science, and human-computer interaction design. Though Exploring Arduino uses the Arduino as a platform to experiment with these concepts, readers can expect to come away from the book with new skills that can be applied to a variety of platforms, projects, and ideas. This is not a recipe book. The projects readers will undertake throughout the book are designed to teach important concepts in addition to traditional programming syntax and engineering theories.

NAN: I see you’ve spent some time introducing engineering concepts to children and teaching them about sustainable engineering and renewable energy. Tell us about those experiences. Any highlights?

JEREMY: The way I see it, there are two ways in which engineers can make the world a better place: they can design new products and technologies that solve global problems or they can teach others the skills they need to assist in the development of solutions to global problems. I try hard to do both, though the latter enables me to have a greater impact, because I am able to multiply my impact by the number of students I teach. I’ve taught workshops, written curriculums, produced videos, written books, and corresponded directly with thousands of students all around the world with the goal of transferring sufficient knowledge for these students to go out and make a difference.

Here are some highlights from my teaching work:


I taught BlueStamp Engineering, a summer program for high school students in NYC in the summer of 2012. I also guest-lectured at the program in 2011 and 2013.

I co-organized a cross-country bus tour where we taught sustainability concepts to school children across the country.

indiaI was invited to speak at Techkriti 2013 in Kanpur, India. I had the opportunity to meet many students from IIT Kanpur who already followed my videos and used my tutorials to build their own projects.

Blum Idea Labs partnered with the St. Louis Hacker Scouts to construct a curriculum for teaching electronics to the students. Though I wasn’t there in person, I did welcome them all to the program with a personalized video.

brooklyn_childrens_zoneThrough CUSD, I organized multiple visits to the Brooklyn Children’s Zone, where my team and I taught students about sustainable architecture and engineering.

Again with CUSD, we visited the Intrepid museum to teach sustainable energy concepts using potato batteries.


NAN: Speaking of promoting engineering to children, what types of technologies do you think will be important in the near future?

JEREMY: I think technologies that make invention more widely accessible are going to be extremely important in the coming years. Cheaper tools, prototyping platforms such as the Arduino and the Raspberry Pi, 3-D printers, laser cutters, and open developer platforms (e.g., Android) are making it easier than ever for any person to become an inventor or an engineer.  Every year, I see younger and younger students learning to use these technologies, which makes me very optimistic about the things we’ll be able to do as a society.

Using Socially Assistive Robots to Address the Caregiver Gap

David Feil-Seifer

Editor’s Note: David Feil-Seifer, a Postdoctoral Fellow in the Computer Science Department at Yale University, wrote this  essay for Circuit Cellar. Feil-Seifer focuses his research on socially assistive robotics (SAR), particularly the study of human-robot interaction for children with autism spectrum disorders (ASD). His dissertation work addressed autonomous robot behavior so that socially assistive robots can recognize and respond to a child’s behavior in unstructured play. He recently was hired as Assistant Professor of Computer Science at the University of Nevada, Reno.

There are looming health care and education crises on the horizon. Baby boomers are getting older and requiring more care, which puts pressure on caregivers. The US nursing shortage is projected to worsen. Similarly, the rapid growth of diagnoses of developmental disorders suggests a greater need for educators, one that the education system is struggling to meet. These great and growing shortfalls in the number of caregivers and educators may be addressed (in part) through the use of socially assistive robotics.

In health care, non-contact repetitive tasks make up a large part of a caregiver’s day. Tasks such as monitoring instruments only require a check to verify that readings are within norms. By offloading these tasks to an automated system, a nurse or doctor could spend more time doing work that better leverages their medical training. A robot can effectively perform simple repetitive tasks (e.g., monitoring breath spirometry exercises or post-stroke rehabilitation compliance).

I coined the term “socially assistive robotics” (SAR) to describe robots that provide such assistance through social rather than physical interaction. My research is the development of SAR algorithms and complete systems relevant to domains such as post-stroke rehabilitation, elder care, and therapeutic interaction for children with autism spectrum disorders (ASD). A key challenge for such autonomous SAR systems is the ability to sense, interpret, and properly respond to human social behavior.

One of my research priorities is developing a socially assistive robotic system for children with ASD. Children with ASD are characterized by social impairments, communication difficulties, and repetitive and stereotyped behaviors. Significant anecdotal evidence indicates that some children with ASD respond socially to robots, which could have therapeutic ramifications. We envision a robot that could act as a catalyst for social interaction, both human-robot and human-human, thus aiding ASD users’ human-human socialization. In such a scenario, the robot is not specifically generating social behavior or participating in social interaction, but instead behaves in a way known to provoke human-human interaction.

David Feil-Seifer developed an autonomous robot that recognizes and appropriately responds to a child’s free-form behavior in play contexts, similar to those seen in some more traditional autism spectrum disorder (ASD) therapies.

Enabling a robot to exhibit and understand social behavior with a child is challenging. Children are highly individual and thus technology used for social interaction needs to be robust to be effective. I developed an autonomous robot that recognizes and appropriately responds to a child’s free-form behavior in play contexts, similar to those seen in some more traditional ASD therapies.

To detect and mitigate child distress, I developed a methodology for learning and then applying a data-driven spatiotemporal model of social behavior based on distance-based features to automatically differentiate between typical vs. aversive child-robot interactions. Using a Gaussian mixture model learned over distance-based feature data, the developed system was able to detect and interpret social behavior with sufficient accuracy to recognize child distress. The robot can use this to change its own behavior to encourage positive social interaction.

To encourage human-human interaction once human-robot interaction was achieved, I developed a navigation planner that used the above spatiotemporal model. This was used to maintain the robot’s spatial relationship with a child to sustain interaction while also guiding the child to a particular location in a room. This could be used to encourage a child to move toward another interaction partner (e.g., a parent). The desired spatial interaction behavior is achieved by modifying an established trajectory planner to weigh candidate trajectories based on conformity to a trained model of the desired behavior.

I also developed a methodology for robot behavior that provides autonomous feedback for a robot-child imitation and turn-taking game. This was accomplished by incorporating an established therapeutic model of feedback along with a trained model of imitation behavior. This is used as part of an autonomous system that can play Simon Says, recognize when the rules have been violated, and provide appropriate feedback.

A growing body of data supports the hypothesis that robots have the potential to aid in addressing the needs of people through non-contact assistance. My research, along with that of many others, has resulted in technical advances for robots providing assistance to people. However, there is a long way to go before these systems can be deployed as a therapeutic platform. Given that the beneficiary populations are growing, and the required therapeutic needs are increasing far more rapidly than the existing resources to address it, SAR could provide lasting benefits to people in need.

David Feil-Seifer, a Postdoctoral Fellow in the Computer Science Department at Yale University, focuses his research on socially assistive robotics (SAR), particularly the study of human-robot interaction for children with autism spectrum disorders (ASD). His dissertation work addressed autonomous robot behavior so that socially assistive robots can recognize and respond to a child’s behavior in unstructured play. David received his MS and PhD in Computer Science from the University of Southern California and a BS in Computer Science from the University of Rochester, NY. He recently was hired as Assistant Professor of Computer Science at the University of Nevada, Reno.

CC275: Shape The Future

In January, Circuit Cellar introduced a new section, Tech the Future, which dedicates page 80 of our magazine to the insights of innovators in groundbreaking technologies.

We’ve reached out to a number of graduate students, professors, researchers, engineers, designers, and entrepreneurs, asking them to write short essays on their fields of expertise, with an emphasis on future trends.

Their topics have included high-speed data acquisition, Linux home automation, research into new materials to replace traditional silicon-based CMOS for circuitry design, control system theory for electronic device DIYers, and how open-source hardware will make world economies more democratic and efficient.

Our contributors have been diverse in more than just their topics. They have been talented

Tech the Future essayist Fergus Dixon designed this DNA sequencer, the subject of an article in the May 2013 issue of Circuit Cellar.

young researchers and seasoned professionals. Male and female. American, Portuguese, Italian, Indian, and Australian.

The one thing they have in common? They keep a close eye on the ever-changing landscape of technological change. And their essays have helped our readers focus on what to watch. We compensate authors for the essays we choose to publish, and we are eager to hear your suggestions on subjects for Tech the Future.

If you are an innovator interested in writing an essay for Tech the Future, e-mail me ( with the topic you’d like to address and some information about yourself. If you are a reader who wants to hear from someone in particular through Tech the Future or has a suggestion for an essay topic, please contact me.

The work of those we’ve featured so far can be found online at Here are just a few of the innovators you will find there:

Maurizio Di Paolo Emilio, a designer of data acquisition software for physics-related experiments and industrial applications, discussing the future of data acquisition technology.

Saptarshi Das, a nano materials researcher who holds a PhD in Electrical Engineering from Purdue University, focusing on the urgent need for alternatives to silicon-based CMOS. These alternative materials, now the subject of extensive scientific research, will be game changers for the microelectronics and nanoelectronics industries, he says.

Fergus Dixon, an Australian entrepreneur and designer of the popular software program “Simulator for Arduino,” explaining why open-source hardware is a valuable tool in the development of new medical devices. Design opportunities for such devices are countless. Hot technologies developed for 3-D printing and unmanned aerial vehicles (UAVs) have direct medical applications, including 3-D-printed prosthetic ears and nanorobots that utilize UAV technology.

Enjoy these articles and others online. In the meantime, I’ll be checking my e-mail for what you would like to see featured in Tech the Future.

New Products: June 2013

C-Programmable Autonomous Mobile Robot System

The RP6v2 is a C-programmable autonomous mobile robot system designed for hobbyists and educators at universities, trade schools, and high schools. The system includes a CD with software, an extensive manual, plenty of example programs, and a large C function library. All library and example programs are open-source GNU general public license (GPL).

The autonomous mobile robot system has a large payload capacity and expansion boards, which may be stacked as needed. It receives infrared (IR) codes in RC5 format and includes integrated light, collision, speed, and IR-obstacle sensors. Its powerful tank drive train can drive up steep ramps and over obstacles.

The RP6v2’s features include an Atmel ATmega32 8-bit RISC microcontroller, AVR-GCC and RobotLoader open-source software for use with Windows and Linux, six PCB expansion areas, two 7.2-VDC motors, an I2C bus expansion system, and a USB interface for easy programming and communication.
The fully assembled RP6v2 robotic system costs $199.

Global Specialties

Smart Panels with Powerful CPU and Multiple OS Support

The SP-7W61 and the SP-1061 smart panels are based on the Texas Instruments 1-GHz Sitara AM3715 Cortex-A8 processor and an Imagination Technologies integrated PowerVR SGX graphics accelerator. The products support multiple OSes—including Linux 2.6.37, Android 2.3.4, and Windows Compact 7—making them well suited for communications, medical and industrial control, human-machine interface (HMI), and transportation applications.

The SP-7W61 (7” and 16:9) and the SP-1061 (10” and 4:3) have a low-power, slim, fanless mechanical design and a high-value cost/performance (C/P) panel PC module that uses powerful and efficient components. Compared with other x86 HMI or open-frame products, the SP-7W61 and the SP-1061 successfully keep power consumption to less than 5.9 W, which is half the typical rate. The smart panels feature multiple display sizes and low power consumption options. They can be implemented into slim and thin chassis types (e.g., for HMI, control panels, or wall-mount controllers).

ADLINK provides full support on software customization based on different platforms. A virtual machine or software development kit (SDK) is provided with related documentation for different platforms, so users can easily set up the software environment.
Contact ADLINK for pricing.

ADLINK Technology, Inc.

Fast-Switching 0.65-TO-20-GHz Synthesizer

The APSYN420B is a 0.65-to-20-GHz frequency synthesizer with a 0.001-Hz resolution and 0.1° phase resolution. The synthesizer provides a nominal output power of 13 dBm into 50 ?. The module features a high-stability internal reference that can be phase-locked to a user-configurable external reference or used in a master-slave configuration for high phase coherence.

The APSYN420B’s key features include low phase noise, fast switching (settling time is typically 20 µs with a 20-µs frequency update), and an internal OCXO reference that can be configured for high phase coherence between multiple sources. The synthesizer offers USB and LAN interfaces and consumes less than 10 W when powered from an external 6-VDC supply.

The APSYN420B’s modulation capabilities include angle, pulse, pulse trains, and pulsed chirps. Linear, logarithmic, or random-frequency sweeps can be performed with combined modulation running. Frequency chirps (linear ramp, up/down) can also be accomplished. The device can accept external reference signals from 1 to 250 MHz.

Applications for the APSYN420B include automatic test equipment, satellite, and other telecommunications needs. The APSYN420B is designed for a 0°C-to-45°C operating temperature range and weighs less than 2 lb in a compact 2.4” × 4.2” × 8.3” enclosure.
Contact Saelig for pricing.

Saelig Co., Inc.

SoC for Next-Generation Multimedia and Navigation Systems

The R-Car H2 is the latest member of Renesas’s R-Car series of automotive system-on-a-chip (SoC) offerings. The SoC delivers more than 25,000 Dhrystone million instructions per second (DMIPS) and provides high-performance and state-of-the-art 3-D graphics capabilities for high-end multimedia and automotive navigation systems.
The R-Car H2 is powered by the ARM Cortex A-15 quad-core configuration running an additional ARM Cortex A-7 quad core. The SoC also features Imagination Technologies’s PowerVR Series6 G6400 graphics processing unit (GPU). The GPU supports open technologies (e.g., OpenGL ES 2.0) and the OpenGL ES 3.0 and OpenCL standards.
The R-Car H2’s bus architecture includes dedicated CPU and IP caches, which reduce the double data rate type three (DDR3) memory bandwidth consumption. To ensure adequate memory bandwidth, the R-Car H2 is equipped with two independent DDR3-1600 32-bit interfaces.

The R-Car H2 integrates advanced automotive interfaces including Ethernet audio video bridging (AVB), MOST150, and CAN and mass storage interfaces such as serial advanced technology attachment (SATA), USB 3.0/2.0, secure digital (SD) card, and PCI Express for system expansion. As a device option, the GPS baseband engine handles all modern navigation standards. The R-Car H2’s additional features include 24-bit digital signal processing (DSP) for codec, high-quality audio processing with hardware sample rate converters, and audio mixing. Its multi-core architecture enables you to implement real-time features (e.g., quick-boot, backup camera support, and media processing) parallel to the execution of advanced OSes, such as QNX Neutrino RTOS, Windows Embedded Automotive, or Linux.

The SoC’s media hardware accelerators enable features such as 4× HD 1080p video encoding/decoding including Blu-ray support at 60 frames per second, image/voice recognition, and high-resolution 3-D graphics with almost no CPU load. These implemented hardware modules also execute the display content improvements needed for HMI/navigation data similar to movie/DVD handling.
Contact Renesas for pricing.

Renesas Electronics Corp.

KNX Device Control

The KNX Gateway enables HAI by Leviton’s Omni and Lumina Ethernet-based controllers to communicate with and control KNX devices through KNX’s standardized network communications bus protocol. You can use an HAI by Leviton interface or automated controller programming to control KNX devices (e.g., lighting devices, temperature and energy management, motors for window coverings, shades, and shutters) in homes and businesses.

The KNX Gateway maps specific data points of each KNX device to a unit or thermostat number on the HAI by Leviton controller. The interface between the KNX Gateway and the HAI by Leviton controller utilizes a RS-485 serial connection.

Compatible controllers include HAI’s OmniPro II home-control system, Omni IIe, Omni LTe, Lumina Pro, and Lumina. The KNX Gateway is powered by either a power over Ethernet (PoE) connection or a 12-to-24-V AC/DC converter.
Contact Leviton for pricing.

Leviton Manufacturing Co., Inc.

DC/DC Controller Uses Only a Single Inductor

The LTC3863 is a high-voltage inverting DC/DC controller that uses a single inductor to produce a negative voltage from a positive-input voltage. All of the controller’s interface signals are positive ground referenced. None of the LTC3863’s pins are connected to a negative voltage, enabling the output voltage to be limited by only the external components selection.

Operating over a 3.5-to-60-V input supply range, the LTC3863 protects against high-voltage transients, operates continuously during automotive cold crank, and covers a broad range of input sources and battery chemistries. The controller helps increase the runtime in battery-powered applications.

It has a low 70-µA quiescent current in Standby mode with the output enabled in Burst Mode operation. The LTC3863’s output voltage can be set from –0.4 to 150 V or lower at up to 3 A typical, making it well suited for 12-or-24-V automotive, heavy equipment, industrial control, telecommunications, and robotic applications.

The LTC3863 drives an external P-channel MOSFET, operates with a selectable fixed frequency between 50 and 850 kHz, and is synchronizable to an external clock from 75 to 750 kHz. Its current-mode architecture provides easy loop compensation, fast transient response, cycle-by-cycle overcurrent protection, and excellent line regulation. Output current sensing is accomplished by measuring the voltage drop across a sense resistor.
The LTC3863’s additional features include programmable soft start or tracking, overvoltage protection, short-circuit protection, and failure mode and effects analysis (FMEA) verification for adjacent pin opens and shorts.

The LTC3863 is offered in 12-pin thermally enhanced MSOP and 3-mm × 4-mm QFN packages. The controllers cost $2.06 in 1,000-unit quantities.

Linear Technology Corp.

Enhanced Web-Based Monitoring Software

HOBOlink is a web-enabled software platform that provides 24/7 data access and remote management for Onset Computer’s web-based HOBO U30 data logging systems. The software’s enhanced version enables users to schedule automatic delivery of exported data files in CSV or XLSX format, via e-mail or FTP.

HOBOlink can configure exported data export in a customized manner. For example, a user with four HOBO U30 systems measuring multiple parameters may configure HOBOlink to automatically export temperature data only. The time range may also be specified.

HOBOlink also enables users to easily access current and historical data, set alarm notifications and relay activations, and manage and control HOBO U30 systems without going into the field. An application programming interface (API) is available to organizations that want to integrate energy and environmental data from HOBOlink web servers with custom software applications.
Contact Onset for pricing.

Onset Computer Corp.

Digitally Tunable Capacitors for LTE Smartphones

Peregrine Semiconductor expanded its DuNE digitally tunable capacitor (DTC) product line with six second-generation devices for antenna tuning in 4G long-term evolution (LTE) smartphones. The PE623060, PE623070, PE623080, and PE623090 (PE6230x0) DTCs have a 0.6-to-7.7-pF capacitance range and support main antenna power handling of up to 34 dBm. The PE621010 and the PE621020 (PE6210x0) DTCs have a 1.38-to-14-pF capacitance range and are optimized for power handling up to 26 dBm, making them well suited for diversity antennas. The highly versatile devices support a variety of tuning circuit topologies, particularly impedance-matching and aperture-tuning applications.
The PE6230x0 DTCs are optimized for key cellular frequency bands from 700 to 2,700 MHz, featuring direct battery voltage operation with consistent performance enabled by on-chip voltage regulation.

The 5-bit, 32-state PE623060/70/80 DTCs have a 0.9-to-4.6-pF capacitance range. The 4-bit, 16-state PE623090 DTC has a 0.6-to-2.35-pF capacitance range. The PE623090 DTC’s lower minimum capacitance solves a critical problem in high-frequency tuning. The 5-bit, 32-state PE6210x0 DTCs support the 100-to-3,000-MHz frequency range. These DTCs extend the range of diversity antennas and improve data rates by optimizing the antenna performance at the operating frequency. The PE621010 DTC has a 1.38-to-5.90-pF capacitance range.

The PE6230x0 and PE6210x0 product families enable designers to develop smaller, higher-performing antennas. The product’s antenna-tuning functions—including bias generation, integrated radio frequency (RF) filtering and bypassing, control interface, and electrostatic discharge (ESD) protection of 2-kV human body model (HBM)—are incorporated into a slim, 0.55-mm × 2-mm × 2-mm package. All decoding and biasing are integrated on-chip, and no external bypassing or filtering components are required.
Contact Peregrine for pricing.

Peregrine Semiconductor Corp.

New Products: May 2013


iC-Haus iC-TW8

The iC-TW8 is a high-resolution signal processor designed to evaluate sine/cosine sensors. Its automatic functions help minimize angular errors and jitters. The processor can be used for initial, push-button calibration and to permanently adapt signal-path parameters during operation. The angular position is calculated at a programmable resolution of up to 65,536 increments per input cycle and output as an indexed incremental signal. A 32-bit word, which includes the counted cycles, is available through the SPI.

As an application-specific DSP, the iC-TW8 has two ADCs that simultaneously sample at a 250-ksps rate, fast CORDIC algorithms, special signal filters, and an analog front end with differential programmable gate amplifier (PGA) inputs that accepts typical magnetic sensor signals from 20 mVPP and up. Signal frequencies of up to 125 kHz enable high rotary and linear speeds for position measuring devices and are processed at a 24-µs constant latency period.

The device’s 12-bit measurement accuracy works with one button press. Measuring tools are not required. The iC-TW8 independently acquires information about the signal corrections needed for offset, amplitude, and phase errors and stores them in an external EEPROM.

The iC-TW8 has two configuration modes. Preset functions and interpolation factors can be retrieved through pins and the device can be calibrated with a button push. No programming is required for initial operation.

The device’s functions—including an AB output divider for fractional interpolation, an advanced signal filter to reduce jitter, a table to compensate for signal distortion, and configurable monitors for errors and signal quality—can be accessed when the serial interfaces are used. Typical applications include magnetic linear displacement measuring systems, optical linear scales, programmable magnetic/optical incremental encoders, high-resolution absolute/incremental angle sensors with on-axis, Hall scanning, and the general evaluation of sine/cosine signals (e.g., PC measuring cards for 1 VPP and 11 µAPP).

The iC-TW8 operates on a 3.1-to-5.5-V single-ended supply within a –40°C-to-125°C extended operating temperature range. It comes in a 48-pin QFN package that requires 7 mm × 7 mm of board space. A ready-to-operate demo board is  available for evaluation. An optional PC operating program, in other words, a GUI, can be connected with a USB adapter.

The iC-TW8 costs $7.69 in 1,000-unit quantities.

iC-Haus GmbH


Analog Devices AD9675

The AD9675 and the AD9674 are the latest additions to Analog Devices’s octal ultrasound receiver portfolio. The devices and are pin compatible with the AD9670/AD9671.

The AD9675 is an eight-channel ultrasound analog front end (AFE) with an on-chip radio frequency (RF) decimator and Analog Devices’s JESD204B serial interface. It is designed for mid- to high-end portable and cart-based medical and industrial ultrasound systems. The device integrates eight channels of a low-noise amplifier, a variable-gain amplifier, an anti-aliasing filter, and a 14-bit ADC with a 125-MSPS sample rate and a 75-dB signal-to-noise ratio (SNR) performance for enhanced ultrasound image quality. The on-chip RF decimator enables the ADC to be oversampled, providing increased SNR for improved image quality while maintaining lower data I/O rates. The 5-Gbps JESD204B serial interface reduces ultrasound system I/O data routing.

The AD9674 offers similar functionality, but includes a standard low-voltage differential signaling (LVDS) interface. Both devices are available in a 144-ball, 10-mm × 10-mm ball grid array (BGA) package.

The AD9674 and the AD9675 cost $62 and $68, respectively.

Analog Devices, Inc.


Melexis MLX92212

Melexis MLX92212

MLX92212 digital output Hall-effect sensors are AEC-Q100-qualified devices that deliver robust, automotive-level performance. The MLX92212LSE-AAA low-hysteresis bipolar latch and the MLX92212LSE-ABA high-hysteresis unipolar switch are optimized for 2.5-to-5.5-V operation. They pair well with many low-power microcontrollers in embedded systems. The sensor and specified microcontroller can share the same power rail. The sensors’ open-drain outputs enable simple connectivity with CMOS/TTL. They exhibit minimal magnetic switch point drift over temperature (up to 150°C) or lifetime and can withstand 8 kV electrostatic discharge.

The MLX92212LSE-AAA is designed for use with multipole ring magnets or alternating magnetic fields. It is well suited for brushless DC electric motor commutation, speed sensing, and magnetic encoder applications. Typical automotive uses include anti-trap/anti-pinch window lift controls, automatic door/hatch systems, and automatic power seat positioning. The MLX92212LSE-ABA enables the use of generic/weak magnets or larger air gaps. It can be used in simple magnetic proximity sensing and interlocks in covers/hatches or ferrous-vane interrupt sensors for precise position and timing applications.

Both MLX92212 devices utilize chopper-stabilized amplifiers with switched capacitors. The CMOS technology makes this technique possible and contributes to the sensors’ low current consumption and small chip size.

The MLX92212 sensors cost $0.35 each in 5,000-unit quantities and $0.30 in 10,000-unit quantities.

Melexis Microelectronic Integrated Systems


Byte SPI Storm

Byte SPI Storm

The SPI Storm 50 and the SPI Storm 10 are the latest versions of Byte Paradigm’s SPI Storm serial protocol host adapter. The adapters support serial peripheral interface (SPI), Quad-SPI, and custom serial protocols in the same USB device.

The SPI Storm 50 and the SPI Storm 10 support serial protocols and master up to 50 and 10 MHz, respectively. The SPI Storm 10 features an 8-MB memory, while the higher-end devices are equipped with a 32-MB memory.

The SPI Storm adapters enable system engineers to access, communicate, and program their digital board and digital ICs, such as field-programmable gate array (FPGA), flash memories, application-specific integrated circuit (ASIC), and

system-on-a-chip (SoC). The SPI Storm 10 is well suited for engineering schools and universities because it is a flexible, all-around access device for hands-on digital electronics. The 50- and 100-MHz versions can be used in mid- and high-end testing and debugging for telecommunications, medical electronics, and digital imaging industries.

The SPI Storm 50 and the SPI Storm 10 cost $530 and $400, respectively.

Byte Paradigm


Microchip MCP19111

Microchip MCP19111

The MCP19111 digitally enhanced power analog controller is a new hybrid, digital and analog power-management device. In combination with the expanded MCP87xxx family of low-figure-of-merit (FOM) MOSFETs, it supports configurable, high-efficiency DC/DC power-conversion designs for many consumer and industrial applications.

The MCP19111 controller, which operates at 4.5 to 32 V, integrates an analog-based PWM controller with a fully functional flash-based microcontroller. This integration offers the flexibility of a digital solution with the speed, performance, and resolution of an analog-based controller.

The MCP19111 devices have integrated MOSFET drivers configured for synchronous, step-down applications. The MCP87018, MCP87030, MCP87090, and MCP87130 are 25-V-rated, 1.8-, 3-, 9-, and 13-mΩ logic-level MOSFETs that are specifically optimized for switched-mode-power-supply (SMPS) applications.

The MCP19111 evaluation board includes Microchip’s high-speed MOSFETs. This evaluation board includes standard firmware, which is user-configurable through an MPLAB X IDE graphical user interface (GUI) plug-in. The combined evaluation board, GUI, and firmware enable power-supply designers to configure and evaluate the MCP19111’s performance for their target applications.

The MCP19111 controllers cost $2.81 each and the MCP87018/030/090/130 MOSFETs cost $0.28 each, all in 5,000-unit quantities.

Microchip Technology, Inc.


Ironwood SG-QFE-7011

Ironwood SG-QFE-7011

The SG-QFE-7011 is a high-performance QFP socket for 0.4-mm pitch, 128-pin QFPs. The socket is designed for a

1.6-mm × 14-mm × 14-mm package size with a 16-mm × 16-mm lead tip to tip. It operates at bandwidths up to 10 GHz with less than 1 dB of insertion loss and has a typical 20 mΩ per I/O contact resistance. The socket connects all pins with 10-GHz bandwidth on all connections. The small-footprint socket is mounted with supplied hardware on the target PCB. No soldering is required. The small footprint enables inductors, resistors, and decoupling capacitors to be placed close to the device for impedance tuning.

The SG-QFE-7011’s swivel lid has a compression screw that enables ICs to be quickly changed out. The socket features a floating compression plate to force down the QFP leads on to elastomer. A hard-stop feature is built into the compression mechanism.

The sockets are constructed with high-performance, low-inductance gold-plated embedded wire on elastomer as interconnect material between a device and a PCB. They feature a –35°C-to-100°C temperature range, a 0.15-nH pin self inductance, a 0.025-nH mutual inductance, a 0.01-pF capacitance to ground, and a 2-A per pin current capacity.

The SG-QFE-7011 costs $474.

Ironwood Electronics

CC270: Forward Progress

As you might have noticed, parts of this issue look a bit different than the publication you’re used to reading. You can see a slightly updated layout, some different colors, and a few new sections. We’ve made these changes to reflect where we are today and where we’re taking this magazine in the months to come. It’s all about forward progress. Here are the broad strokes:


We’re planning an exciting layout redesign for 2013. The layout will be modern, clean, and engaging, but its fonts and colors won’t distract you from what you’re reading—professional engineering content. Since the new layout is still an issue or two away, we’re presenting you with this freshened up issue to mark the transition to 2013. We hope you like the changes.


On page 20 you’ll find a new section that will appear frequently in the coming months. The purpose of our client profiles is to shine a light on one company per month and bring you an exclusive offer for useful products or services.


Last month we ran Steve Ciarcia’s final “Priority Interrupt” editorial. This month we’re introducing a new section, “Tech the Future.” The EE/ECE community is on the verge of major breakthroughs in the fields of microcomputing, wireless communication, robotics, and programming. Each month, we’ll use page 80 to present some of the fresh ideas, thought-provoking research projects, and new embedded design-related endeavors from innovators who are working on the groundbreaking technologies of tomorrow.


You’ll soon have Circuit Cellar’s 25th (“CC25”) anniversary issue in your hands or on your PCs or mobile devices. Here are just a few of the exciting topics in the issue: Circuit Cellar in 1988, design/programming tips, engineers’ thoughts on the future of embedded tech, and much more. It’s going to be a classic.

Well, there’s certainly a lot of publishing-related innovation going on at our headquarters. And I know you’re equally busy at your workbenches. Just be sure to schedule some quiet time this month to read the articles in this issue. Perhaps one of our authors will inspire you to take on your first project of the new year. We feature articles on topics ranging from an MCU-based  helicopter controller to open-source hardware to embedded authentication to ’Net-based tools for energy efficiency. Enjoy!