Q&A: Marilyn Wolf, Embedded Computing Expert

Marilyn Wolf has created embedded computing techniques, co-founded two companies, and received several Institute of Electrical and Electronics Engineers (IEEE) distinctions. She is currently teaching at Georgia Institute of Technology’s School of Electrical and Computer Engineering and researching smart-energy grids.—Nan Price, Associate Editor

NAN: Do you remember your first computer engineering project?

MARILYN: My dad is an inventor. One of his stories was about using copper sewer pipe as a drum memory. In elementary school, my friend and I tried to build a computer and bought a PCB fabrication kit from RadioShack. We carefully made the switch features using masking tape and etched the board. Then we tried to solder it and found that our patterning technology outpaced our soldering technology.

NAN: You have developed many embedded computing techniques—from hardware/software co-design algorithms and real-time scheduling algorithms to distributed smart cameras and code compression. Can you provide some information about these techniques?

Marilyn Wolf

Marilyn Wolf

MARILYN: I was inspired to work on co-design by my boss at Bell Labs, Al Dunlop. I was working on very-large-scale integration (VLSI) CAD at the time and he brought in someone who designed consumer telephones. Those designers didn’t care a bit about our fancy VLSI because it was too expensive. They wanted help designing software for microprocessors.

Microprocessors in the 1980s were pretty small, so I started on simple problems, such as partitioning a specification into software plus a hardware accelerator. Around the turn of the millennium, we started to see some very powerful processors (e.g., the Philips Trimedia). I decided to pick up on one of my earliest interests, photography, and look at smart cameras for real-time computer vision.

That work eventually led us to form Verificon, which developed smart camera systems. We closed the company because the market for surveillance systems is very competitive.
We have started a new company, SVT Analytics, to pursue customer analytics for retail using smart camera technologies. I also continued to look at methodologies and tools for bigger software systems, yet another interest I inherited from my dad.

NAN: Tell us a little more about SVT Analytics. What services does the company provide and how does it utilize smart-camera technology?

MARILYN: We started SVT Analytics to develop customer analytics for software. Our goal is to do for bricks-and-mortar retailers what web retailers can do to learn about their customers.

On the web, retailers can track the pages customers visit, how long they stay at a page, what page they visit next, and all sorts of other statistics. Retailers use that information to suggest other things to buy, for example.

Bricks-and-mortar stores know what sells but they don’t know why. Using computer vision, we can determine how long people stay in a particular area of the store, where they came from, where they go to, or whether employees are interacting with customers.

Our experience with embedded computer vision helps us develop algorithms that are accurate but also run on inexpensive platforms. Bad data leads to bad decisions, but these systems need to be inexpensive enough to be sprinkled all around the store so they can capture a lot of data.

NAN: Can you provide a more detailed overview of the impact of IC technology on surveillance in recent years? What do you see as the most active areas for research and advancements in this field?

MARILYN: Moore’s law has advanced to the point that we can provide a huge amount of computational power on a single chip. We explored two different architectures: an FPGA accelerator with a CPU and a programmable video processor.

We were able to provide highly accurate computer vision on inexpensive platforms, about $500 per channel. Even so, we had to design our algorithms very carefully to make the best use of the compute horsepower available to us.

Computer vision can soak up as much computation as you can throw at it. Over the years, we have developed some secret sauce for reducing computational cost while maintaining sufficient accuracy.

NAN: You wrote several books, including Computers as Components: Principles of Embedded Computing System Design and Embedded Software Design and Programming of Multiprocessor System-on-Chip: Simulink and System C Case Studies. What can readers expect to gain from reading your books?

MARILYN: Computers as Components is an undergraduate text. I tried to hit the fundamentals (e.g., real-time scheduling theory, software performance analysis, and low-power computing) but wrap around real-world examples and systems.

Embedded Software Design is a research monograph that primarily came out of Katalin Popovici’s work in Ahmed Jerraya’s group. Ahmed is an old friend and collaborator.

NAN: When did you transition from engineering to teaching? What prompted this change?

MARILYN: Actually, being a professor and teaching in a classroom have surprisingly little to do with each other. I spend a lot of time funding research, writing proposals, and dealing with students.

I spent five years at Bell Labs before moving to Princeton, NJ. I thought moving to a new environment would challenge me, which is always good. And although we were very well supported at Bell Labs, ultimately we had only one customer for our ideas. At a university, you can shop around to find someone interested in what you want to do.

NAN: How long have you been at Georgia Institute of Technology’s School of Electrical and Computer Engineering? What courses do you currently teach and what do you enjoy most about instructing?

MARILYN: I recently designed a new course, Physics of Computing, which is a very different take on an introduction to computer engineering. Instead of directly focusing on logic design and computer organization, we discuss the physical basis of delay and energy consumption.

You can talk about an amazingly large number of problems involving just inverters and RC circuits. We relate these basic physical phenomena to systems. For example, we figure out why dynamic RAM (DRAM) gets bigger but not faster, then see how that has driven computer architecture as DRAM has hit the memory wall.

NAN: As an engineering professor, you have some insight into what excites future engineers. With respect to electrical engineering and embedded design/programming, what are some “hot topics” your students are currently attracted to?

MARILYN: Embedded software—real-time, low-power—is everywhere. The more general term today is “cyber-physical systems,” which are systems that interact with the physical world. I am moving slowly into control-oriented software from signal/image processing. Closing the loop in a control system makes things very interesting.

My Georgia Tech colleague Eric Feron and I have a small project on jet engine control. His engine test room has a 6” thick blast window. You don’t get much more exciting than that.

NAN: That does sound exciting. Tell us more about the project and what you are exploring with it in terms of embedded software and closed-loop control systems.

MARILYN: Jet engine designers are under the same pressures now that have faced car engine designers for years: better fuel efficiency, lower emissions, lower maintenance cost, and lower noise. In the car world, CPU-based engine controllers were the critical factor that enabled car manufacturers to simultaneously improve fuel efficiency and reduce emissions.

Jet engines need to incorporate more sensors and more computers to use those sensors to crunch the data in real time and figure out how to control the engine. Jet engine designers are also looking at more complex engine designs with more flaps and controls to make the best use of that sensor data.

One challenge of jet engines is the high temperatures. Jet engines are so hot that some parts of the engine would melt without careful design. We need to provide more computational power while living with the restrictions of high-temperature electronics.

NAN: Your research interests include embedded computing, smart devices, VLSI systems, and biochips. What types of projects are you currently working on?

MARILYN: I’m working on with Santiago Grivalga of Georgia Tech on smart-energy grids, which are really huge systems that would span entire countries or continents. I continue to work on VLSI-related topics, such as the work on error-aware computing that I pursued with Saibal Mukopodhyay.

I also work with my friend Shuvra Bhattacharyya on architectures for signal-processing systems. As for more unusual things, I’m working on a medical device project that is at the early stages, so I can’t say too much specifically about it.

NAN: Can you provide more specifics about your research into smart energy grids?

MARILYN: Smart-energy grids are also driven by the push for greater efficiency. In addition, renewable energy sources have different characteristics than traditional coal-fired generators. For example, because winds are so variable, the energy produced by wind generators can quickly change.

The uses of electricity are also more complex, and we see increasing opportunities to shift demand to level out generation needs. For example, electric cars need to be recharged, but that can happen during off-peak hours. But energy systems are huge. A single grid covers the eastern US from Florida to Minnesota.

To make all these improvements requires sophisticated software and careful design to ensure that the grid is highly reliable. Smart-energy grids are a prime example of Internet-based control.

We have so many devices on the grid that need to coordinate that the Internet is the only way to connect them. But the Internet isn’t very good at real-time control, so we have to be careful.

We also have to worry about security Internet-enabled devices enable smart grid operations but they also provide opportunities for tampering.

NAN: You’ve earned several distinctions. You were the recipient of the Institute of Electrical and Electronics Engineers (IEEE) Circuits and Systems Society Education Award and the IEEE Computer Society Golden Core Award. Tell us about these experiences.

MARILYN: These awards are presented at conferences. The presentation is a very warm, happy experience. Everyone is happy. These things are time to celebrate the field and the many friends I’ve made through my work.

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
editor@circuitcellar.com

Member Profile: Scott Weber

Scott Weber

Scott Weber

LOCATION:
Arlington, Texas, USA

MEMBER STATUS:
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.

TECH INTERESTS:
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.

RECENT EMBEDDED TECH ACQUISITION:
Scott said he recently treated himself to a brand-new Fluke 77-IV multimeter.

CURRENT PROJECTS:
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.”

THOUGHTS ON THE FUTURE OF EMBEDDED TECH:
“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!”

Arduino-Based Hand-Held Gaming System

gameduino2-WEBJames Bowman, creator of the Gameduino game adapter for microcontrollers, recently made an upgrade to the system adding a Future Technology Devices International (FTDI) FT800 chip to drive the graphics. Associate Editor Nan Price interviewed James about the system and its capabilities.

NAN: Give us some background. Where do you live? Where did you go to school? What did you study?

Bowman-WEB

James Bowman

 JAMES: I live on the California coast in a small farming village between Santa Cruz and San Francisco. I moved here from London 17 years ago. I studied computing at Imperial College London.

NAN: What types of projects did you work on when you were employed by Silicon Graphics, 3dfx Interactive, and NVIDIA?

JAMES: Always software and hardware for GPUs. I began in software, which led me to microcode, which led to hardware. Before you know it you’ve learned Verilog. I was usually working near the boundary of software and hardware, optimizing something for cost, speed, or both.

NAN: How did you come up with the idea for the Gameduino game console?

JAMES: I paid for my college tuition by working as a games programmer for Nintendo and Sega consoles, so I was quite familiar with that world. It seemed a natural fit to try to give the Arduino some eye-catching color graphics. Some quick experiments with a breadboard and an FPGA confirmed that the idea was feasible.

NAN: The Gameduino 2 turns your Arduino into a hand-held modern gaming system. Explain the difference from the first version of Gameduino—what upgrades/additions have been made?

Gameduinofinal-WEB

The Gameduino2 uses a Future Technology Devices International chip to drive its graphics

JAMES: The original Gameduino had to use an FPGA to generate graphics, because in 2011 there was no such thing as an embedded GPU. It needs an external monitor and you had to supply your own inputs (e.g., buttons, joysticks, etc.). The Gameduino 2 uses the new Future Technology Devices International (FTDI) FT800 chip, which drives all the graphics. It has a built-in color resistive touchscreen and a three-axis accelerometer. So it is a complete game system—you just add the CPU.

NAN: How does the Arduino factor into the design?

GameduinoPCB-WEB

An Arduino, Ethernet adapter, and a Gameduino

 JAMES: Arduino is an interesting platform. It is 5 V, believe it or not, so the design needs a level shifter. Also, the Arduino is based on an 8-bit microcontroller, so the software stack needs to be carefully built to provide acceptable performance. The huge advantage of the Arduino is that the programming environment—the IDE, compiler, and downloader—is used and understood by hundreds of thousands of people.

 NAN: Is it easy or possible to customize the Gameduino 2?

 JAMES: I would have to say no. The PCB itself is entirely surface mount technology (SMT) and all the ICs are QFNs—they have no accessible pins! This is a long way from the DIP packages of yesterday, where you could change the circuit by cutting tracks and soldering onto the pins.

I needed a microscope and a hot air station to make the Gameduino2 prototype. That is a long way from the “kitchen table” tradition of the Arduino. Fortunately the Arduino’s physical design is very customization-friendly. Other devices can be stacked up, adding networking, hi-fi sound, or other sensor inputs.

 NAN: The Gameduino 2 project is on Kickstarter through November 7, 2013. Why did you decide to use Kickstarter crowdfunding for this project?

 JAMES: Kickstarter is great for small-scale inventors. The audience it reaches also tends to be interested in novel, clever things. So it’s a wonderful way to launch a small new product.

NAN: What’s next for Gameduino 2? Will the future see a Gameduino 3?

 JAMES: Product cycles in the Arduino ecosystem are quite long, fortunately, so a Gameduino 3 is distant. For the Gameduino 2, I’m writing a book, shipping the product, and supporting the developer community, which will hopefully make use of it.

 

Programmable Logic Video Lessons

Interested in learning more about programmable logic? You’re in luck. Colin O’Flynn’s first article in his “Programmable Logic in Practice” column appears in Circuit Cellar’s October 2013 issue. To accompany his work, Colin is producing informative videos for you to view after reading his articles.

In the first video, Colin covers the topic of adding the Xilinx ChipScope ILA/VIO core using automatic and manual insertion with ISE.

 

Since 2002, Circuit Cellar has published several of O’Flynn’s articles. O’Flynn  is an engineer and lecturer at Dalhousie University in Halifax, Nova Scotia. He earned a Master’s in applied science from Dalhousie and pursued further graduate studies in cryptographic systems. Over the years, he has developed a wide variety of skills ranging from electronic assembly (including SMDs) to FPGA design in Verilog and VHDL to high-speed PCB design.