About Nan Price

Nan Price is an Associate Editor at Circuit Cellar. You can reach her at nprice@circuitcellar.com and @assoceditor_cc.

EMC Measurement Technology

LangerSX near-field probes enable electromagnetic compatibility (EMC) analyses of interferences emitted by electronic boards, components, and IC pins with high internal frequencies. The SX-R3-1 magnetic H-field probe is designed to detect high-frequency magnetic fields with a high geometrical resolution. The field orientation and distribution can be detected by moving the probe around conductor runs, bypass capacitors, EMC components, and within IC pin and supply system areas. The SX-E03 E-field probe detects bus structures and larger components.

The probes have a 1-to-10-GHz frequency range. Their high resolution (the SX R3-1 achieves 1 mm and the SX E03 covers up to 4 mm × 4 mm) enables them to pinpoint RF sources on densely packed boards or on IC pins. The magnetic-field probe heads are electrically shielded. The probes are connected to a spectrum analyzer input via a shielded cable and SMA connectors during measurement. High clock rates of 2 GHz, for example, may result in fifth-order harmonics of up to 10 GHz. These harmonics are coupled out by RF sources on the board (e.g., conductor-run segments, ICs, and other components). They may stimulate other structural parts of the board to oscillate and emit interferences.

Contact Langer for pricing.

Langer EMV-Technik

Q&A: Raspberry Pi Innovation

Orlando, FL-based web app developer and blogger Shea Silverman recently received Kickstarter funding for the latest version of PiPlay, his Raspberry Pi-based OS. Shea and I discussed his ongoing projects, his Raspberry Pi book, and what’s next for PiPlay.—Nan Price, Associate Editor



Shea Silverman

NAN: What is your current occupation?

SHEA: Web applications developer with the Center for Distributed Learning at the University of Central Florida (UCF).

NAN: Why and when did you decide to start your blog?

SHEA: I’ve been blogging on and off for years, but I could never keep to a schedule or really commit myself to writing. After I started working on side projects, I realized I needed a place to store tips and tricks I had figured out. I installed WordPress, posted some PhoneGap tips, and within a day got a comment from someone who had the same issue, and my tips helped them out. I have been blogging ever since. I make sure to post every Friday night.

NAN: Tell us about PiPlay, the Raspberry Pi OS. Why did you start the OS? What new developments, if any, are you working on?


Shea’s PiPlay Raspberry Pi OS recently reached 400% funding on Kickstarter.

SHEA: PiPlay is a gaming and emulation distribution for the Raspberry Pi single-board computer. It is built on top of the Raspbian OS, and tries to make it as easy as possible to play games on your Raspberry Pi. My blog got really popular after I started posting binaries and tutorials on how to compile different emulators to the Raspberry Pi, but I kept getting asked the same questions and saw users struggling with the same consistent issues.

I decided I would release a disk image with everything preconfigured and ready to be loaded onto an SD card. I’ve been adding new emulators, games, and tools to it ever since.

I just recently completed a Kickstarter that is funding the next release, which includes a much nicer front end, a web GUI, and a better controller configuration system.

NAN: You wrote Instant Raspberry Pi Gaming. Do you consider this book introductory or is it written for the more experienced engineer?

SHEA: Instant Raspberry Pi Gaming is written like a cookbook with recipes for doing various tasks. Some of them are very simple, and they build up to some more advanced recipes. One of the easier tasks is creating your user account on the Pi Store, while the more advanced recipes have you working with Python and using an API to interact with Minecraft.

Readers will learn how to setup a Raspberry Pi, install and use various emulators and games, a bit about the Minecraft API, and common troubleshooting tips.


The Pitroller is a joystick and buttons hooked up to the GPIO pins of a Raspberry Pi, which can act as a controller or keyboard for various emulators.

NAN: You are a member of FamiLAB, an Orlando, FL-based community lab/hackerspace. What types of projects have you worked on at the lab?


Disney director Rich Moore poses with Shea’s miniature arcade machine. The machine was based on Fix It Felix Jr. from Disney’s Wreck It Ralph.

SHEA: I spend a lot of time at the lab using the laser cutter. Creating a 2-D vector in Inkscape, and then watching it be cut out on a piece of wood or acrylic is really inspiring. My favorite project was making a little arcade machine featuring Fix It Felix Jr. from Wreck It Ralph. A marketing person from Disney was able to get it into the hands of the director Rich Moore. He sent me a bunch of pictures of himself holding my little arcade machine next to the full size version.

NAN: Give us a little background information. How did you become interested in technology?

SHEA: My mom always likes to remind me that I’ve been using computers since I was 2. My parents were very interested in technology and encouraged my curiosity when it came to computers. I always liked to take something apart and see how it worked, and then try to put it back together. As the years went on, I’ve devoted more and more time to making technology a major part of my life.

NAN: Tell us about the first embedded system you designed.

SHEA: I have a lot of designs, but I don’t think I’ve ever finished one. I’ll be halfway into a project, learn about something new, then cannibalize what I was working on and repurpose it for my new idea. One of the first embedded projects I worked on was a paintball board made out of a PICAXE microcontroller. I never got it small enough to fit inside the paintball marker, but it was really cool to see everything in action. The best part was when I finally had that “ah-ha!” moment, and everything I was learning finally clicked.

NAN: What was the last electronics-design related product you purchased and what type of project did you use it with?

SHEA: At UCF, one of our teams utilizes a ticket system for dealing with requests. Our department does a hack day each semester, so my coworker and I decided to rig up a system that changes the color of the lights in the office depending on the urgency of requests in the box. We coded up an API and had a Raspberry Pi ping the API every few minutes for updates. We then hooked up two Arduinos to the Raspberry Pi and color-changing LED strips to the Arduinos. We set it up and it’s been working for the past year and a half, alerting the team with different colors when there is work to do.

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

SHEA: My Kickstarter for PiPlay just finished at 400% funding. So right now I’m busy working on fulfilling the rewards, and writing the latest version of PiPlay.

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

SHEA: Wearable computing. Google Glass, the Pebble smart watch, Galaxy Gear—I think these are all great indicators of where our technology is heading. We currently have very powerful computers in our pockets with all kinds of sensors and gadgets built in, but very limited ways to physically interact with them (via the screen, or a keypad). If we can make the input devices modular, be it your watch, a heads-up display, or something else, I think that is going to spark a new revolution in user experiences.

Integrated Wi-Fi System in Package Module

EconaisThe EC19W01 is a small, smart, highly integrated 802.11b/g/n Wi-Fi system in package (SiP) module. The module is well suited for home automation and smart appliances; Wi-Fi audio speakers and headphones; wireless sensors and sensor networks; wireless monitoring (audio and video); smart appliances; health care and fitness devices; wearable devices; security, authentication, and admittance control; lighting; building/energy/industrial management/control; cloud-connected devices; remote control, data acquisition, and monitoring; and machine-to-machine (M2M) and Internet of Things (IoT) design.

The EC19W01’s features include an integrated 32-bit processor to support application customization, on-board flash and antenna, low power consumption, support for Serial-to-Wi-Fi and SPI-to-Wi-Fi, wireless transmit/receive rates of up to 20 Mbps, and a small 14-mm × 16-mm × 2.8-mm footprint.

Contact Econais for pricing.

Econais, Inc.

Q&A: Embedded Applications Consultant and Hacker Quinn Dunki

Quinn Dunki is more than just a hacker. This Los Angeles, CA-based embedded applications consultant and software game developer enjoys working on her homebrew 8-bit computer and dreams of a future filled with hackerspace-type libraries.—Nan Price, Associate Editor


NAN: Tell us about your computer game company, One Girl, One Laptop Productions. How did the company begin?

Quinn Dunki

Quinn Dunki

QUINN: I had been in the AAA games industry for most of my career. I’ve been making games in my spare time since I was six years old, but the “actually-getting-paid-for-it” time started in the 1990s with the Nintendo 64.

I’ve written games on everything from the Apple II to the Playstation 3. I worked at various companies including Bungie Studios and 3DO.

My longest stint was eight good years at a small studio called Pandemic in Los Angeles, CA. In 2009, the company was in financial trouble and was sold to Electronic Arts with the intention it would keep it going. Electronic Arts opted to close the studio down shortly thereafter. We got some severance with our walking papers, and I decided to spin that money into One Girl, One Laptop Productions

This was just at the tail end of the initial gold rush on Apple’s iOS platform, and it still seemed like there was money to be made there. Unfortunately, there was subsequently a mad rush to the bottom on pricing for iPhone games. Before I could establish a presence, the space got very crowded almost overnight. Low-volume, high-quality indie games became financially unviable (though I think they’re coming back now). I still do independent game development on the side, but my primary business now is consulting and hired-gun engineering for other companies needing mobile or embedded applications.

Quinn has two workspaces. She uses this one for the “small clean stuff.”

Quinn has two workspaces. She uses this one for the “small clean stuff.”

Quinn’s other workspace is used for the “big dirty stuff.”

NAN: Describe some of the software One Girl, One Laptop Productions develops. Do you have a favorite?

QUINN: As much as I love games, my true love is engineering itself. My favorite projects always end up being the ones with the most complex challenges. I don’t think I could pick just one.

A good recent example is the Olloclip, which is a combination photography app and lens attachment for the iPhone. The main killer feature is real-time barrel distortion correction that made for some very interesting development challenges.

Much like game consoles, working on mobile devices is often about taking a well-understood algorithm and making it work on a platform so small that nobody thinks it will be possible. On AAA games, I used to try and build complex artificial intelligence (AI) systems that ran in 3 ms of frame time. Now I’m trying to cram gigabyte-scale image processing systems into devices with little memory, minimal graphics processing units (GPUs), and slow CPUs. They are similar challenges with completely different contexts. Some days it feels like you’re trying to model high-energy particle physics on a washing machine, but it’s a great when you finally do solve a problem like that. It’s the engineering of the thing that’s exciting, whatever that thing is this week.

Another favorite has been the ICEdot project. It’s a health and safety sensor system that works with your mobile device and is targeted at athletes and coaches. It’s a fun mix of mobile and embedded systems development and it has pushed my skill set into a number of new areas—in particular, Bluetooth Low Energy (BLE), which is an exciting new technology. ICEdot is on the bleeding edge of that, and it’s been a big challenge to use it in the real world.

NAN: What types of projects did you work on while you were a Senior Engineer at Pandemic Studios?

QUINN: I started my tenure there on a squad tactics training simulator Pandemic was building for Simulation, Training, and Instrumentation Command (STRICOM), an experimental technology branch of the US Army. It’s a long story, but that simulator was later spun into a series of Xbox games called Full Spectrum Warrior.

The biggest project I worked on was an open-world game set in World War II called Saboteur. Unlike the usual shooter format the WWII genre is littered with, this was a third-person action-adventure game with a noir art style. Saboteur was a hugely ambitious project, and the awesome team there solved some very big challenges. We did things with physics, rendering, AI, clambering, animation, toolchains, content streaming, and game design that no game had done before. As so often happens with AAA games, the marketing budget was pulled at the last moment, so you can add it to the long list of “Greatest Games That Nobody Played.”

NAN: Your blog-style website BlondiHacks features hacking projects involving everything from development boards to two-layer PCB etching. Tell us about the types of projects you enjoy hacking.

QUINN: BlondiHacks is my outlet for whatever whim that comes to mind as far as hacking. I think hacking is more than a hobby—it’s kind of a way of life. It’s about shaping your environment to be what you think it should be. It’s about saving things from landfills and giving new life to forgotten or underappreciated artifacts. It’s part creativity, part environmentalism, part self-reliance, and all good times.

It’s fun to talk about stuff you’re doing, but most of my flights of fancy are so obscure or odd that only a select few would find them interesting. The power of the Internet is that it connects all of us oddballs to each other. Hence, BlondiHacks.

NAN: How did you become interested in technology?

QUINN: I don’t recall a time when I wasn’t interested, honestly, so that transition must have occurred before my brain was retaining memories. What age is that? Three? Four?
I may have been born with a multimeter in my hand (though my mom would probably have noted that in the medical report). My mom likes to say, the day they brought the Apple II into the house (when I was around age five) I crawled up on the stool and haven’t moved since.

To prolong her toothbrush’s life, Quinn replaced a toothbrush battery with a nickel–cadmium battery and added wires to the old battery’s PCB mount points.

To prolong her toothbrush’s life, Quinn replaced a toothbrush battery with a nickel–cadmium battery and added wires to the old battery’s PCB mount points.

NAN: What was your first project?

QUINN: That’s difficult to say, since my life is a series of endless overlapping projects. As soon as I was old enough to hold a soldering iron, I built a lot of things from the seminal Forrest Mims book RadioShack sold. You know the one: Getting Started in Electronics.
That book was my bible for many years. I remember hacking a remote-control truck to have headlights and speed control. I remember building a working guillotine for a school project about the French Revolution. It was 4’ tall and genuinely dangerous. I carried it on the bus and demonstrated it on bourgeoisie bananas in class. I don’t imagine kids would get away with that today.

More recently, my interest in hacking was probably rekindled with the simple act of replacing the “non-user-serviceable” battery in a very expensive toothbrush (see “Toothbrush Repair”). That was five years ago, and I’m still using that toothbrush today. To me, that’s the purest essence of hacking right there—fixing the one weakness in a product that would have otherwise halved its useful life.

Quinn’s homebrew computer, Veronica, includes a clock circuit and a CPU. The breadboard is shown.

Quinn’s homebrew computer, Veronica, includes a clock circuit and a CPU. The breadboard is shown.

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

QUINN: My biggest hobby project recently has been my homebrew computer, Veronica (see “Veronica”). The Apple II I mentioned was very formative for me, and [Apple Computer founder] Steve Wozniak was a bit of a hero figure. My whole life, I wanted to know how one person could just sit down and create something like that.

A couple of years ago, with no formal training in electrical engineering, I decided to see if I could do it. Veronica is the result, and it was the fulfillment of a lifelong goal to build a functioning, usable, 8-bit computer from scratch, complete with video graphics array (VGA) bitmapped video, a keyboard, game controllers, and built-in Pong.

Today, my most active project is repairing, restoring, and modifying an early 1990s Bally/Williams pinball machine called Johnny Mnemonic (see “Johnny”). Anyone who likes hacking should be into pinball machines. They are wonderlands of mechanical systems, electronics, software, and game theory all rolled into one. They are also bottomless pits of hacking and tinkering potential (not to mention money pits and time sinks).

Another big ongoing project is our 24 Hours of LeMons race team. The short version is that it’s a (very) low-budget form of endurance auto racing that involves a whole lot of hacking of all kinds. That’s probably an entire interview unto itself, but I feel I should at least mention it, since it’s such a big part of my hacking time.

Quinn is in the process of hacking a Bally/Williams Johnny Mnemonic pinball machine. This photo shows the machine’s circuitry.

Quinn is in the process of hacking a Bally/Williams Johnny Mnemonic pinball machine. This photo shows the machine’s circuitry.

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

QUINN: One “big idea“ that has been put forward that I’m excited about is the notion of hackerspaces replacing public libraries. The Internet is gradually replacing the role of pure information access that libraries have served. It has been suggested that access to high-end technology creation tools is the next such area where playing field leveling is required. Anyone wanting to improve their station in life by executing their ideas in a high-tech world will need access to CNC machines, 3-D printers, machine tools, high-end computer-aided design (CAD), video production software, and so forth.

Libraries are generally well located and already equipped with things such as fire exits, sprinkler systems, and commercial-grade electrical. Converting some libraries into hackerspaces sounds to me like a terrific use of public funds. It’s a bit “pie in the sky,” but places like Edmonton in Alberta, Canada, and North Logan, UT, are already experimenting with the idea. This is like hacking democracy itself, and I love it.

8-Bit Microcontroller IP Core

DigitalCoreDesignThe DF6808 IP core is binary-compatible with the industry-standard Motorola 68HC08 8-bit microcontroller. The IP core uses sophisticated on-chip peripheral capabilities to perform 45 to 100 million instructions per second. FAST architecture implemented in DF6808 enables the 68HC08 microcontroller to run at least three times faster than the original solution.

The DF6808’s 16-bit, free-running timer system has two input-capture lines and two output-compare lines. The IP core is equipped with proprietary safety functions, including self-monitoring circuitry, which helps protect against system errors; the computer operating properly (COP) watchdog system, which protects against software failures; and an illegal opcode detection circuit, which provides a non-maskable interrupt if an illegal opcode occurs.

For power conservation, the IP core includes two software-controlled power-saving modes (Wait and Stop). These modes make the DF6808 IP core well suited for automotive and battery-driven applications.

The DF6808 includes the DoCDTM real-time hardware debugger, which provides built-in support for Digital Core Design’s hardware debug system and the debugging capability of an entire system-on-a-chip (SoC). The DoCDTM enables nonintrusive debugging of running applications. It can halt, run, step into, or skip an instruction and read/write any microcontroller contents, including all registers, user-defined peripherals, data, and program memories.

Contact Digital Core Design for pricing.

Digital Core Design

Closed-Loop Module

CogiscanThe LCR Control Module is a fully integrated and closed-loop system designed to eliminate the risk of placing incorrect passive components on PCBs. Combined with the Offline Job Setup and/or Line Setup Control module, the LCR Control Module’s software is integrated with an electrical LCR meter. The system verifies that the measured values (e.g., inductance, capacitance, resistance) are within the tolerances specified for the component. This electrical verification can be done at any time prior to mounting the reel on the placement machine.

Contact Cogiscan for pricing.

Cogiscan, Inc.

A Serene Workspace for Board Evaluation and Writing

 Elecronics engineer, entrepreneur, and author Jack Ganssle recently sent us information about his Finksburg, MD, workspace:

I’m in a very rural area and I value the quietness and the view out of the window over my desk. However, there are more farmers than engineers here so there’s not much of a high-tech community! I work out of the house and share an office with my wife, who handles all of my travel and administrative matters. My corner is both lab space and desk. Some of the equipment changes fairly rapidly as vendors send in gear for reviews and evaluation.


Ganssle’s desk is home to ever-changing equipment. His Agilent Technologies MSO-X-3054A mixed-signal oscilloscope is a mainstay.

The centerpiece, though, is my Agilent Technologies MSO-X-3054A mixed-signal oscilloscope. It’s 500 MHz, 4 GSps, and includes four analog channels and 16 digital channels, as well as a waveform generator and protocol analyzer. I capture a lot of oscilloscope traces for articles and talks, and the USB interface sure makes that easy. That’s pretty common on oscilloscopes, now, but being an old-timer I remember struggling with a Polaroid scope camera.

The oscilloscope’s waveform generator has somewhat slow (20-ns) rise time when making pulses, so the little circuit attached to it sharpens this to 700 ps, which is much more useful for my work. The photo shows a Siglent SDS1102CML oscilloscope on the bench that I’m currently evaluating. It’s amazing how much capability gets packed into these inexpensive instruments.

The place is actually packed with oscilloscopes and logic analyzers, but most are tucked away. I don’t know how many of those little USB oscilloscope/logic analyzers vendors have sent for reviews. I’m partial to bench instruments, but do like the fact that the USB instruments are typically quite cheap. Most have so-so analog performance but the digital sampling is generally great.

Only barely visible in the picture, under the bench there’s an oscilloscope from 1946 with a 2” CRT I got on eBay just for fun. It’s a piece of garbage with a very nonlinear timebase, but a lot of fun. The beam is aimed by moving a magnet around! Including the CRT there are only four tubes. Can you imagine making anything with just four transistors today?

The big signal generator is a Hewlett-Packward 8640B, one of the finest ever made with astonishing spectral purity and a 0.5-dB amplitude flatness across 0.5 MHz to 1 GHz. A couple of digital multimeters and a pair of power supplies are visible as well. The KORAD supply has a USB connection and a serviceable, if klunky, PC application that drives it. Sometimes an experiment needs a slowly changing voltage, which the KORAD manages pretty well.

They’re mostly packed away, but I have a ton of evaluation kits and development boards. A Xilinx MicroZed is shown on the bench. It’s is a very cool board that has a pair of Cortex-A9s plus FPGA fabric in a single chip.

I use IDEs and debuggers from, well, everyone: Microchip Technology, IAR Systems, Keil, Segger, you name it. These run on a variety of processors but, along with so many others, more and more I’m using Cortex-M series parts.

My usual lab work is either evaluating boards, products and instruments, or running experiments that turn into articles. It pains me to see so much engineering is done via superstition today. For example, people pick switch contact debounce times based on hearsay or smoke signals or something. Engineers need data, so I tested about 50 pairs of switches to determine what real bounce characteristics are. The results are on my website. Ditto for watchdog timers and other important issues embedded people deal with.

Ganssle notes that his other “bench” is his woodworking shop. To learn more about Ganssle, read our 2013 interview.

Low-Power Micromodule

The ECM-DX2 is a highly integrated, low-power consumption micromodule. Its fanless operation and extended temperature are supported by the DMP Vortex86DX2 system-on-a-chip (SoC) CPU. The micromodule is targeted for industrial automation, transportation/vehicle construction, and aviation applications.
The ECM-DX2 withstands industrial operation environments for –40-to-75°C temperatures and supports 12-to-26-V voltage input. Multiple OSes, including Windows 2000/XP and Linux, can be used in a variety of embedded designs.

AvalueThe micromodule includes on-board DDR2 memory that supports up to 32-bit, 1-GB, and single-channel 24-bit low-voltage differential signaling (LVDS) as well as video graphics array (VGA) + LVDS or VGA + TTL multi-display configurations. The I/O deployment includes one SATA II interface, four COM ports, two USB 2.0 ports, 8-bit general-purpose input/output (GPIOs), two Ethernet ports, and one PS/2 connector for a keyboard and a mouse. The ECM-DX2 also provides a PC/104 expansion slot and one MiniPCIe card slot.

Contact Avalue Technology for pricing.

Avalue Technology, Inc.

Programmable Logic Controller Board

SmartTILE illustration 6.psdThe SmartTILE (Smart TRi Integrated Logic Engine) is a programmable logic controller CPU board that plugs onto a carrier I/O board. The board integrates a 32-bit CPU, ferroelectric RAM (FRAM) and flash memory, a battery-backed real-time clock, and an Ethernet port on board. Its digital, analog, and serial I/O signals are brought to a user’s carrier board via three sets of header pins.

All critical components are already built-in on board. A user just needs to design a simple carrier PCB that contains a D/A circuit that interfaces the SmartTILE’s low-voltage signals to real-world voltages and currents (e.g., 24, 120, or 240 V).

The SmartTILE-Fx provides 16 digital inputs, 16 digital outputs (5-V CMOS logic level), eight analog inputs, and four analog outputs (12-bit, 0-5V) and can be expanded to 128 digital inputs and 128 digital outputs. The controller board -Fx provides three channels of serial ports (3.3 V, TX, RX, and /RTS) that can interface to RS-232, RS-485, or even wireless radio. An I2C port (3.3 V) is also available, allowing OEM to interface to specialty ICs that support I2Cbus.

Contact Triangle Research International for pricing.

Triangle Research International, Inc.

Stand-Alone, 8-Channel Event, State, and Count Data Logger

DATAQThe DI-160 is a stand-alone event, state, and count data logger that features four programmable measurement modes. The data logger enables you to determine when events occur, the total number of events, and the period of time in between events. It can count parts by monitoring a proximity sensor’s pulse output, or determine a machine’s downtime by monitoring AC power.

The DI-160 includes eight channels. Four ±300-VDC/peak AC isolated channels can accommodate high-level DC voltage signals, pulse inputs up 2 kHz, or AC line voltage. Four ±30-VDC/peak AC non-isolated channels (pulled high) enable you to monitor lower-level DC voltages, TTL-level, signals, or switch closures.

You can use DATAQ’s Event Recorder set-up software, which is included with the data logger, to enable/disable channels, select measurement modes on a channel-by-channel basis, and choose one of 21 sample intervals, ranging from 1 s to 24 h. Data is stored to a removable SD memory card in CSV format, enabling up to 500 days of continuous recording and easy viewing in Microsoft Excel.

The DI-160’s AC channels provide channel-to-channel and input-to-output isolation up to 500 VDC (±250-V peak AC) and have a 4-V trigger threshold. The low-voltage channels are protected up to ±30 VDC/peak AC and trigger at 2.5 V.

A built-in rechargeable battery acts as a “bridge” when disconnecting the data logger from a PC and connecting it to the USB power supply. Three LEDs indicate when the DI-160 is actively acquiring data, when the unit is connected via USB to a PC (or the included AC power supply), and the battery’s charge state. A push button enables you to start and stop recording to the SD memory card.

The DI-160’s four selectable measurement modes. State mode determines an event’s duration. Event mode detects a single change of state (within a sample interval). High-Speed (HS) Counter mode yields the total number of state changes within a sample interval. AC Counter mode counts the number of times AC power turns on/off within a sample interval.

The DI-160 costs $299 and includes a mini screwdriver a 2-GB SD memory card, an AC power supply, and a mini-USB cable. The DATAQ Event Recorder software is available for free download.

DATAQ Instruments, Inc.

Q&A: Embedded Systems Consultant

Elecia White is an embedded systems engineer, consultant, author, and innovator. She has worked on a variety of projects: DNA scanners, health-care monitors, learning toys, and fingerprint recognition.—Nan Price, Associate Editor


NAN: Tell us about your company Logical Elegance. When and why did you start the company? What types of services do you provide?

ELECIA: Logical Elegance is a small San Jose, CA-based consulting firm specializing in embedded systems. We do system analysis, architecture, and software implementation for a variety of devices.

Elecia White

Elecia White

I started the company in 2004, after leaving a job I liked for a job that turned out to be horrible. Afterward, I wasn’t ready to commit to another full-time job; I wanted to dip my toe in before becoming permanent again.

I did eventually take another full-time job at ShotSpotter, where I made a gunshot location system. Logical Elegance continued when my husband, Chris, took it over. After ShotSpotter, I returned to join him. While we have incorporated and may take on a summer intern, for the most part Logical Elegance is only my husband and me.

I like consulting, it lets me balance my life better with my career. It also gives me time to work on my own projects: writing a book and articles, playing with new devices, learning new technologies. On the other hand, I could not have started consulting without spending some time at traditional companies. Almost all of our work comes from people we’ve worked with in the past, either people we met at companies where we worked full time or people who worked for past clients.

Here is Elecia’s home lab bench. She conveniently provided notes.

Here is Elecia’s home lab bench. She conveniently provided notes.

NAN: Logical Elegance has a diverse portfolio. Your clients have ranged from Cisco Systems to LeapFrog Enterprises. Tell us about some of your more interesting projects.

ELECIA: We are incredibly fortunate that embedded systems are diverse, yet based on similar bedrock. Once you can work with control loops and signal processing, the applications are endless. Understanding methodologies for concepts such as state machines, interrupts, circular buffers, and working with peripherals allows us to put the building blocks together a different way to suit a particular product’s need.

For example, for a while there, it seemed like some of my early work learning how to optimize systems to make big algorithms work on little processors would fall to the depths of unnecessary knowledge. Processors kept getting more and more powerful. However, as I work on wearables, with their need to optimize cycles to extend their battery life, it all is relevant again.

We’ve had many interesting projects. Chris is an expert in optical coherence tomography (OCT). Imagine a camera that can go on the end of a catheter to help a doctor remove plaque from a clogged artery or to aid in eye surgery. Chris is also the networking expert. He works on networking protocols such as Locator/ID Separation Protocol (LISP) and multicast.

I’m currently working for a tiny company that hopes to build an exoskeleton to help stroke patients relearn how to walk. I am incredibly enthusiastic about both the application and the technology.

That has been a theme in my career, which is how I’ve got this list of awesome things I’ve worked on: DNA scanners, race cars and airplanes, children’s toys, and a gunshot location system. The things I leave off the list are more difficult to describe but no less interesting to have worked on: a chemical database that used hydrophobicity to model uptake rates, a medical device for the operating room and ICU, and methods for deterring fraud using fingerprint recognition on a credit card.

Elecia says one of the great things about the explosion of boards and kits available is being able to quickly build a system. However, she explains, once the components work together, it is time to spin a board. (This system may be past that point.)

Elecia says one of the great things about the explosion of boards and kits available is being able to quickly build a system. However, she explains, once the components work together, it is time to spin a board. (This system may be past that point.)

In the last few years, Chris and I have both worked for Fitbit on different projects. If you have a One pedometer, you have some of my bits in your pocket.

The feeling of people using my code is wonderful. I get a big kick seeing my products on store shelves. I enjoyed working with Fitbit. When I started, it was a small company expanding its market; definitely the underdog. Now it is a success story for the entire microelectromechanical systems (MEMS) industry.

Not everything is rosy all the time though. For one start-up, the algorithms were neat, the people were great, and the technology was a little clunky but still interesting. However, the client failed and didn’t pay me (and a bunch of other people).

When I started consulting, I asked a more experienced friend about the most important part. I expected to hear that I’d have to make myself more extroverted, that I’d have to be able to find more contracts and do marketing, and that I’d be involved in the drudgery of accounting. The answer I got was the truth: the most important part of consulting is accounts receivable. Working for myself—especially with small companies—is great fun, but there is a risk.

NAN: How did you get from “Point A” to Logical Elegance?

ELECIA: ”Point A” was Harvey Mudd College in Claremont, CA. While there, I worked as a UNIX system administrator, then later worked with a chemistry professor on his computational software. After graduation, I went to Hewlett Packard (HP), doing standard software, then a little management. I was lured to another division to do embedded software (though we called it firmware).

Next, a start-up let me learn how to be a tech lead and architect in the standard start-up sink-or-swim methodology. A mid-size company gave me exposure to consumer products and a taste for seeing my devices on retailer’s shelves.

From there, I tried out consulting, learned to run a small business, and wrote a Circuit Cellar Ink article “Open Source Code Guide” (Issue 175, 2005). I joined another tiny start-up where I did embedded software, architecture, management, and even directorship before burning out. Now, I’m happy to be an embedded software consultant, author, and podcast host.

NAN: You wrote Making Embedded Systems: Design Patterns for Great Software (O’Reilly Media, 2011). What can readers expect to learn from the book?

ELECIA: While having some industry experience in hardware or software will make my book easier to understand, it is also suitable for a computer science or electrical engineering college student.

It is a technical book for software engineers who want to get closer to the hardware or electrical engineers who want to write good software. It covers many types of embedded information: hardware, software design patterns, interview questions, and a lot of real-world wisdom about shipping products.

Elecia White's BookMaking Embedded Systems is intended for engineers who are in transition: the hardware engineer who ends up writing software or the software engineer who suddenly needs to understand how the embedded world is different from pure software.

Unfortunately, most college degrees are either computer science or electrical engineering. Neither truly prepares for the half-and-half world of an embedded software engineer. Computer science teaches algorithms and software design methodology. Electrical engineering misses both of those topics but provides a practical tool kit for doing low-level development on small processors. Whichever collegiate (or early career) path, an embedded software engineer needs to have familiarity with both.

I did a non-traditional major that was a combination of computer science and engineering systems. I was prepared for all sorts of math (e.g., control systems and signal processing) and plenty of programming. All in all, I learned about half of the skills I needed to do firmware. I was never quite sure what was correct and what I was making up as I went along.

As a manager, I found most everyone was in the same boat: solid foundations on one side and shaky stilts on the other. The goal of the book is to take whichever foundation you have and cantilever a good groundwork to the other half. It shouldn’t be 100% new information. In addition to the information presented, I’m hoping most people walk away with more confidence about what they know (and what they don’t know).

Elecia was a judge at the MEMS Elevator Pitch Session at the 2013 MEMS Executive Congress in Napa, CA.

Elecia was a judge at the MEMS Elevator Pitch Session at the 2013 MEMS Executive Congress in Napa, CA.

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

ELECIA: I was a software engineer at the NetServer division at HP. I kept doing lower-level software, drivers mostly, but for big OSes: WinNT, OS/2, Novell NetWare, and SCO UNIX (a list that dates my time there).

HP kept trying to put me in management but I wasn’t ready for that path, so I went to HP Labs’s newly spun-out HP BioScience to make DNA scanners, figuring the application would be more interesting. I had no idea.

I lit a board on fire on my very first day as an embedded software engineer. Soon after, a motor moved because my code told it to. I was hooked. That edge of software, where the software touches the physical, captured my imagination and I’ve never looked back.

NAN: Tell us about the first embedded system you designed. Where were you at the time? What did you learn from the project?

ELECIA: Wow, this one is hard. The first embedded system I designed depends on your definition of “designed.” Going from designing subsystems to the whole system to the whole product was a very gradual shift, coinciding with going to smaller and smaller companies until suddenly I was part of the team not only choosing processors but choosing users as well.

After I left the cushy world of HP Labs with a team of firmware engineers, several electrical engineers, and a large team of software engineers who were willing to help design and debug, I went to a start-up with fewer than 50 people. There was no electrical engineer (except for the EE who followed from HP). There was a brilliant algorithms guy but his software skills were more MATLAB-based than embedded C. I was the only software/firmware engineer. This was the sort of company that didn’t have source version control (until after my first day). It was terrifying being on my own and working without a net.

I recently did a podcast about how to deal with code problems that feel insurmountable. While the examples were all from recent work, the memories of how to push through when there is no one else who can help came from this job.

Elecia is shown recording a Making Embedded Systems episode with the founders of electronics educational start-up Light Up. From left to right: Elecia’s husband and producer Christopher White, host Elecia White, and guests Josh Chan and Tarun Pondicherry.

Elecia is shown recording a Making Embedded Systems episode with the founders of electronics educational start-up Light Up. From left to right: Elecia’s husband and producer Christopher White, host Elecia White, and guests Josh Chan and Tarun Pondicherry.

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

ELECIA: I have a few personal projects I’m working on: a T-shirt that monitors my posture and a stuffed animal that sends me a “check on Lois” text if an elderly neighbor doesn’t pat it every day. These don’t get nearly enough of my attention these days as I’ve been very focused on my podcast: Making Embedded Systems on iTunes, Instacast, Stitcher, or direct from http://embedded.fm.

The podcast started as a way to learn something new. I was going to do a half-dozen shows so I could understand how recording worked. It was a replacement for my normal community center classes on stained glass, soldering, clay, hula hooping, laser cutting, woodshop, bookbinding, and so forth.

However, we’re way beyond six shows and I find I quite enjoy it. I like engineering and building things. I want other people to come and play in this lovely sandbox. I do the show because people continue to share their passion, enthusiasm, amusement, happiness, spark of ingenuity, whatever it is, with me.

To sum up why I do a podcast, in order of importance: to talk to people who love their jobs, to share my passion for engineering, to promote the visibility of women in engineering, and to advertise for Logical Elegance (this reason is just in case our accountant reads this since we keep writing off expenses).

NAN: What are your go-to embedded platforms? Do you have favorites, or do you use a variety of different products?

ELECIA: I suppose I do have favorites but I have a lot of favorites. At any given time, my current favorite is the one that is sitting on my desk. (Hint!)

I love Arduino although I don’t use it much except to get other people excited. I appreciate that at the heart of this beginner’s board (and development system) is a wonderful, useful processor that I’m happy to work on.

I like having a few Arduino boards around, figuring that I can always get rid of the bootloader and use the Atmel ATmega328 on its own. In the meantime, I can give them to people who have an idea they want to try out.

For beginners, I think mbed’s boards are the next step after Arduino. I like them but they still have training wheels: nice, whizzy training wheels but still training wheels. I have a few of those around for when friends’ projects grow out of Arduinos. While I’ve used them for my own projects, their price precludes the small-scale production I usually want to do.

Professionally, I spend a lot of time with Cortex-M3s, especially those from STMicroelectronics and NXP Semiconductors. They seem ubiquitous right now. These are processors that are definitely big enough to run an RTOS but small enough that you don’t have to. I keep hearing that Cortex-M0s are coming but the price-to-performance-to-power ratio means my clients keep going to the M3s.

Finally, I suppose I’ll always have a soft spot for Texas Instruments’s C2000 line, which is currently in the Piccolo and Delfino incarnations. The 16-bit byte is horrible (especially if you need to port code to another processor), but somehow everything else about the DSP does just what I want. Although, it may not be about the processor itself: if I’m using a DSP, I must be doing something mathy and I like math.

NAN: Do you have any predictions for upcoming “hot topics?”

ELECIA: I’m most excited about health monitoring. I’m surprised that Star Trek and other science fiction sources got tricorders right but missed the constant health monitoring we are heading toward with the rise of wearables and the interest in quantified self.
I’m most concerned about connectivity. The Internet of Things (IoT) is definitely coming, but many of these devices seem to be more about applying technology to any device that can stand the price hit, whether it makes sense or not.

Worse, the methods for getting devices connected keeps fracturing as the drive toward low-cost and high functionality leads the industry in different directions. And even worse, the ongoing battle between security and ease of use manages to give us things that are neither usable nor secure. There isn’t a good solution (yet). To make progress we need to consider the application, the user, and what they need instead of applying what we have and hoping for the best.

Gigabit Ethernet Designs

WurthWurth Electronics Midcom and Lantiq recently announced The Evaluation Kit, a jointly developed demonstration kit. The kit enables users to easily add Ethernet hardware to an application or device and provides all necessary information to understand the demands of an Ethernet hardware design.

The Evaluation Kit includes an easy-to-use 1-Gbps demonstration board. The (54-mm × 92-mm) credit card-sized demonstration board is powered by USB. The board plugs into PCs and provides up to 1-Gbps bidirectional data rates.

The Evaluation Kit costs approximately $175.

Wurth Electronics Midcom, Inc.


16-Bit Digitizer

SpectrumThe M2i.4960 and the M2i.4961 mid-speed 16-bit digitizers are available for PCI/PCI-X and PCIe. The devices offer two or four synchronous channels with a 60 megasamples-per-second (MSPS) speed and a 30-MHz bandwidth.

The channels can be individually switched between single-ended and true differential input mode, therefore single-ended and differential signals can be simultaneously acquired with one digitizer. Each input channel includes an on-board calibration. The channels can be software programmed for proper termination, user offset, and input range.

The devices’ acquisition modes include segmented acquisition, gated acquisition, or streaming mode. The devices also feature a versatile clock and trigger section, making them suitable for a variety of different applications. Multiple cards can be internally synchronized to obtain more synchronous channels or to directly synchronize to arbitrary and digital waveform generators or digital waveform capture cards.

A digital input option enables up to 32 synchronous digital input channels to be acquired by multiplexing them into the analog data in different ways. Each of the 16 digital inputs can completely replace one analog channel or each of the 2/4 digital inputs can be stored together with the A/D sample by reducing its resolution.

Contact Spectrum for pricing.

Spectrum GmbH

Ultra-Compact Ultrasonic Sensor Series

MaxbotixThe UCXL-MaxSonar-WR series of sensors are flexible, OEM-customizable products that can be integrated into a system with MaxBotix’s horns or flush-mounted into an existing housing. Mounting design recommendations are provided through MaxBotix’s 3-D CAD models (available in multiple formats) to facilitate your design process. The sensor layout offers four conveniently placed mounting holes for design flexibility.

The rugged, high performance sensors are individually calibrated and feature a 1-cm resolution, an operational temperature range from –40˚C to 70˚C, real-time automatic calibration (voltage, humidity, and ambient noise), 200,000+ h mean time between failures (MTBF), and an operational 3-to-5.5-V voltage range with a low 3.4-mA average current requirement.

Contact MaxBotix for pricing.

MaxBotix, Inc.

Low-Power Remote-Control Transceivers

LinxThe TT Series remote-control transceiver is designed for bidirectional, long-range, remote-control applications. The module includes an optimized frequency-hopping spread spectrum (FHSS) RF transceiver and an integrated remote-control transcoder.

The FHSS is capable of reaching more than 2 miles in typical line-of-sight environments with 0-dB gain antennas. An amplified version increases the output power from 12.5 to 23.5 dBm, boosting the range to more than 8 miles in line-of-sight environments with 0-dB antennas.

The TT Series transceiver features best-in-class receive sensitivity (up to −111 dBm) and low power consumption (only 19.2 mA in receive mode and 36 mA in transmit mode at 12.5 dBm). The initial version operates in the 902-to-928-Hz frequency band for North and South America.

The transceiver is housed in a compact reflow-compatible surface-mount technology (SMT) package. It doesn’t require any external RF components except an antenna, which simplifies integration and reduces assembly costs.

Programming is not required for basic operation. The transceiver’s primary settings are hardware-selectable, which eliminates the need for an external microcontroller or other digital interface. Eight status lines can be set up in any combination of inputs and outputs to transfer button or contact states. A selectable acknowledgement indicates that the transmission was successfully received. For advanced features, a UART interface provides optional software configuration.

A simple pairing operation configures two modules to operate together. A single button press on each side causes the modules to automatically swap their 32-bit addresses and store them in nonvolatile memory. It can be configured to automatically send an acknowledgement to the transmitting unit either after receiving a command or with external circuitry when an action has taken place. An optional external processor can send two data bytes with the acknowledgement.

The TT Series transceiver module is available as part of Linx Technologies’s master development system that comes with two development boards for benchmarking and prototyping. Each board is populated with a transceiver, two remote-control development boards, and programming boards. The system also includes antennas, a daughterboard with a USB interface, demonstration software, extra modules, and connectors.

Contact Linx Technologies for pricing.

Linx Technologies