Q&A: Scott Garman, Technical Evangelist

Scott Garman is more than just a Linux software engineer. He is also heavily involved with the Yocto Project, an open-source collaboration that provides tools for the embedded Linux industry. In 2013, Scott helped Intel launch the MinnowBoard, the company’s first open-hardware SBC. —Nan Price, Associate Editor

Scott Garman

Scott Garman

NAN: Describe your current position at Intel. What types of projects have you developed?

SCOTT: I’ve worked at Intel’s Open Source Technology Center for just about four years. I began as an embedded Linux software engineer working on the Yocto Project and within the last year, I moved into a technical evangelism role representing Intel’s involvement with the MinnowBoard.

Before working at Intel, my background was in developing audio products based on embedded Linux for both consumer and industrial markets. I also started my career as a Linux system administrator in academic computing for a particle physics group.

Scott was involved with an Intel MinnowBoard robotics and computer vision demo, which took place at LinuxCon Japan in May 2013.

Scott was involved with an Intel MinnowBoard robotics and computer vision demo, which took place at LinuxCon Japan in May 2013.

I’m definitely a generalist when it comes to working with Linux. I tend to bounce around between things that don’t always get the attention they need, whether it is security, developer training, or community outreach.

More specifically, I’ve developed and maintained parallel computing clusters, created sound-level management systems used at concert stadiums, worked on multi-room home audio media servers and touchscreen control systems, dug into the dark areas of the Autotools and embedded Linux build systems, and developed fun conference demos involving robotics and computer vision. I feel very fortunate to be involved with embedded Linux at this point in history—these are very exciting times!

Scott is shown working on an Intel MinnowBoard demo, which was built around an OWI Robotic Arm.

Scott is shown working on an Intel MinnowBoard demo, which was built around an OWI Robotic Arm.

NAN: Can you tell us a little more about your involvement with the Yocto Project (www.yoctoproject.org)?

SCOTT: The Yocto Project is an effort to reduce the amount of fragmentation in the embedded Linux industry. It is centered on the OpenEmbedded build system, which offers a tremendous amount of flexibility in how you can create embedded Linux distros. It gives you the ability to customize nearly every policy of your embedded Linux system, such as which compiler optimizations you want or which binary package format you need to use. Its killer feature is a layer-based architecture that makes it easy to reuse your code to develop embedded applications that can run on multiple hardware platforms by just swapping out the board support package (BSP) layer and issuing a rebuild command.

New releases of the build system come out twice a year, in April and October.

Here, the OWI Robotic Arm is being assembled.

Here, the OWI Robotic Arm is being assembled.

I’ve maintained various user space recipes (i.e., software components) within OpenEmbedded (e.g., sudo, openssh, etc.). I’ve also made various improvements to our emulation environment, which enables you to run QEMU and test your Linux images without having to install it on hardware.

I created the first version of a security tracking system to monitor Common Vulnerabilities and Exposures (CVE) reports that are relevant to recipes we maintain. I also developed training materials for new developers getting started with the Yocto Project, including a very popular introductory screencast “Getting Started with the Yocto Project—New Developer Screencast Tutorial

NAN: Intel recently introduced the MinnowBoard SBC. Describe the board’s components and uses.

SCOTT: The MinnowBoard is based on Intel’s Queens Bay platform, which pairs a Tunnel Creek Atom CPU (the E640 running at 1 GHz) with the Topcliff Platform controller hub. The board has 1 GB of RAM and includes PCI Express, which powers our SATA disk support and gigabit Ethernet. It’s an SBC that’s well suited for embedded applications that can use that extra CPU and especially I/O performance.

Scott doesn’t have a dedicated workbench or garage. He says he tends to just clear off his desk, lay down some cardboard, and work on things such as the Trippy RGB Waves Kit, which is shown.

Scott doesn’t have a dedicated workbench or garage. He says he tends to just clear off his desk, lay down some cardboard, and work on things such as the Trippy RGB Waves Kit, which is shown.

The MinnowBoard also has the embedded bus standards you’d expect, including GPIO, I2C, SPI, and even CAN (used in automotive applications) support. We have an expansion connector on the board where we route these buses, as well as two lanes of PCI Express for custom high-speed I/O expansion.

There are countless things you can do with MinnowBoard, but I’ve found it is especially well suited for projects where you want to combine embedded hardware with computing applications that benefit from higher performance (e.g., robots that use computer vision, as a central hub for home automation projects, networked video streaming appliances, etc.).

And of course it’s open hardware, which means the schematics, Gerber files, and other design files are available under a Creative Commons license. This makes it attractive for companies that want to customize the board for a commercial product; educational environments, where students can learn how boards like this are designed; or for those who want an open environment to interface their hardware projects.

I created a MinnowBoard embedded Linux board demo involving an OWI Robotic Arm. You can watch a YouTube video to see how it works.

NAN: What compelled Intel to make the MinnowBoard open hardware?

SCOTT: The main motivation for the MinnowBoard was to create an affordable Atom-based development platform for the Yocto Project. We also felt it was a great opportunity to try to release the board’s design as open hardware. It was exciting to be part of this, because the MinnowBoard is the first Atom-based embedded board to be released as open hardware and reach the market in volume.

Open hardware enables our customers to take the design and build on it in ways we couldn’t anticipate. It’s a concept that is gaining traction within Intel, as can be seen with the announcement of Intel’s open-hardware Galileo project.

NAN: What types of personal projects are you working on?

SCOTT: I’ve recently gone on an electronics kit-building binge. Just getting some practice again with my soldering iron with a well-paced project is a meditative and restorative activity for me.

Scott’s Blinky POV Kit is shown. “I don’t know what I’d do without my PanaVise Jr. [vise] and some alligator clips,” he said.

Scott’s Blinky POV Kit is shown. “I don’t know what I’d do without my PanaVise Jr. [vise] and some alligator clips,” he said.

I worked on one project, the Trippy RGB Waves Kit, which includes an RGB LED and is controlled by a microcontroller. It also has an IR sensor that is intended to detect when you wave your hand over it. This can be used to trigger some behavior of the RGB LED (e.g., cycling the colors). Another project, the Blinky POV Kit, is a row of LEDs that can be programmed to create simple text or logos when you wave the device around, using image persistence.

Below is a completed JeeNode v6 Kit Scott built one weekend.

Below is a completed JeeNode v6 Kit Scott built one weekend.

My current project is to add some wireless sensors around my home, including temperature sensors and a homebrew security system to monitor when doors get opened using 915-MHz JeeNodes. The JeeNode is a microcontroller paired with a low-power RF transceiver, which is useful for home-automation projects and sensor networks. Of course the central server for collating and reporting sensor data will be a MinnowBoard.

NAN: Tell us about your involvement in the Portland, OR, open-source developer community.

SCOTT: Portland has an amazing community of open-source developers. There is an especially strong community of web application developers, but more people are hacking on hardware nowadays, too. It’s a very social community and we have multiple nights per week where you can show up at a bar and hack on things with people.

This photo was taken in the Open Source Bridge hacker lounge, where people socialize and collaborate on projects. Here someone brought a brainwave-control game. The players are wearing electroencephalography (EEG) readers, which are strapped to their heads. The goal of the game is to use biofeedback to move the floating ball to your opponent’s side of the board.

This photo was taken in the Open Source Bridge hacker lounge, where people socialize and collaborate on projects. Here someone brought a brainwave-control game. The players are wearing electroencephalography (EEG) readers, which are strapped to their heads. The goal of the game is to use biofeedback to move the floating ball to your opponent’s side of the board.

I’d say it’s a novelty if I wasn’t so used to it already—walking into a bar or coffee shop and joining a cluster of friendly people, all with their laptops open. We have coworking spaces, such as Collective Agency, and hackerspaces, such as BrainSilo and Flux (a hackerspace focused on creating a welcoming space for women).

Take a look at Calagator to catch a glimpse of all the open-source and entrepreneurial activity going on in Portland. There are often multiple events going on every night of the week. Calagator itself is a Ruby on Rails application that was frequently developed at the bar gatherings I referred to earlier. We also have technical conferences ranging from the professional OSCON to the more grassroots and intimate Open Source Bridge.

I would unequivocally state that moving to Portland was one of the best things I did for developing a career working with open-source technologies, and in my case, on open-source projects.

MCU-Based Projects and Practical Tasks

Circuit Cellar’s January issue presents several microprocessor-based projects that provide useful tools and, in some cases, entertainment for their designers.

Our contributors’ articles in the Embedded Applications issue cover a hand-held PIC IDE, a real-time trailer-monitoring system, and a prize-winning upgrade to a multi-zone audio setup.

Jaromir Sukuba describes designing and building the PP4, a PIC-to-PIC IDE system for programming and debugging a Microchip Technology PIC18. His solar-powered,

The PP4 hand-held PIC-to-PIC programmer

The PP4 hand-held PIC-to-PIC programmer

portable computing device is built around a Digilent chipKIT Max32 development platform.

“While other popular solutions can overshadow this device with better UI and OS, none of them can work with 40 mW of power input and have fully in-house developed OS. They also lack PP4’s fun factor,” Sukuba says. “A friend of mine calls the device a ‘camel computer,’ meaning you can program your favorite PIC while riding a camel through endless deserts.”

Not interested in traveling (much less programming) atop a camel? Perhaps you prefer to cover long distances towing a comfortable RV? Dean Boman built his real-time trailer monitoring system after he experienced several RV trailer tire blowouts. “In every case, there were very subtle changes in the trailer handling in the minutes prior to the blowouts, but the changes were subtle enough to go unnoticed,” he says.

Boman’s system notices. Using accelerometers, sensors, and a custom-designed PCB with a Microchip Technology PIC18F2620 microcontroller, it continuously monitors each trailer tire’s vibration and axle temperature, displays that information, and sounds an alarm if a tire’s vibration is excessive.  The driver can then pull over before a dangerous or trailer-damaging blowout.

But perhaps you’d rather not travel at all, just stay at home and listen to a little music? This issue includes Part 1 of Dave Erickson’s two-part series about upgrading his multi-zone home audio system with an STMicroelectronics STM32F100 microprocessor, an LCD, and real PC boards. His MCU-controlled, eight-zone analog sound system won second-place in a 2011 STMicroelectronics design contest.

In addition to these special projects, the January issue includes our columnists exploring a variety of  EE topics and technologies.

Jeff Bachiochi considers RC and DC servomotors and outlines a control mechanism for a DC motor that emulates a DC servomotor’s function and strength. George Novacek explores system safety assessment, which offers a standard method to identify and mitigate hazards in a designed product.

Ed Nisley discusses a switch design that gives an Arduino Pro Mini board control over its own power supply. He describes “a simple MOSFET-based power switch that turns on with a push button and turns off under program control: the Arduino can shut itself off and reduce the battery drain to nearly zero.”

“This should be useful in other applications that require automatic shutoff, even if they’re not running from battery power,” Nisley adds.

Ayse K. Coskun discusses how 3-D chip stacking technology can improve energy efficiency. “3-D stacked systems can act as energy-efficiency boosters by putting together multiple chips (e.g., processors, DRAMs, other sensory layers, etc.) into a single chip,” she says. “Furthermore, they provide high-speed, high-bandwidth communication among the different layers.”

“I believe 3-D technology will be especially promising in the mobile domain,” she adds, “where the data access and processing requirements increase continuously, but the power constraints cannot be pushed much because of the physical and cost-related constraints.”

Small, Self-Contained GNSS Receiver

TM Series GNSS modules are self-contained, high-performance global navigation satellite system (GNSS) receivers designed for navigation, asset tracking, and positioning applications. Based on the MediaTek chipset, the receivers can simultaneously acquire and track several satellite constellations, including the US GPS, Europe’s GALILEO, Russia’s GLONASS, and Japan’s QZSS.

LinxThe 10-mm × 10-mm receivers are capable of better than 2.5-m position accuracy. Hybrid ephemeris prediction can be used to achieve less than 15-s cold start times. The receiver can operate down to 3 V and has a 20-mA low tracking current. To save power, the TM Series GNSS modules have built-in receiver duty cycling that can be configured to periodically turn off. This feature, combined with the module’s low power consumption, helps maximize battery life in battery-powered systems.

The receiver modules are easy to integrate, since they don’t require software setup or configuration to power up and output position data. The TM Series GNSS receivers use a standard UART serial interface to send and receive NMEA messages in ASCII format. A serial command set can be used to configure optional features. Using a USB or RS-232 converter chip, the modules’ UART can be directly connected to a microcontroller or a PC’s UART.

The GPS Master Development System connects a TM Series Evaluation Module to a prototyping board with a color display that shows coordinates, a speedometer, and a compass for mobile evaluation. A USB interface enables simple viewing of satellite data and Internet mapping and custom software application development.
Contact Linx Technologies for pricing.

Linx Technologies

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.

Compact Wi-Fi Transceiver


The LEMOS-LMX-WiFi wireless transceiver

The LEMOS-LMX-WiFi is a compact wireless transceiver that can operate on IEEE 802.11 networks. It is supported by a 32-bit microcontroller running a scalable TCP/IP stack. The transceiver is well suited for wireless embedded applications involving digital remote control, digital and analog remote monitoring, asset tracking, security systems, point of sale terminals, sensor monitoring, machine-to-machine (M2M) communication, environmental monitoring and control.

The 40.64-mm × 73.66-mm transceiver is available in two models: integrated PCB antenna or external antenna. Its features include software-selectable analog and digital I/O pins, a 2-Mbps maximum data rate, and a unique IEEE MAC address.

The LEMOS-LMX-WiFi can be powered by any 3.3-V to – 6-VDC source that can deliver 200 mA of current. The transceiver can interface to external devices that communicate via USART, I2C, and SPI. It also supports infrastructure and ad hoc networks.

Contact Lemos International for pricing.

Lemos International, Inc.

I/O Raspberry Pi Expansion Card

The RIO is an I/O expansion card intended for use with the Raspberry Pi SBC. The card stacks on top of a Raspberry Pi to create a powerful embedded control and navigation computer in a small 20-mm × 65-mm × 85-mm footprint. The RIO is well suited for applications requiring real-world interfacing, such as robotics, industrial and home automation, and data acquisition and control.

RoboteqThe RIO adds 13 inputs that can be configured as digital inputs, 0-to-5-V analog inputs with 12-bit resolution, or pulse inputs capable of pulse width, duty cycle, or frequency capture. Eight digital outputs are provided to drive loads up to 1 A each at up to 24 V.
The RIO includes a 32-bit ARM Cortex M4 microcontroller that processes and buffers the I/O and creates a seamless communication with the Raspberry Pi. The RIO processor can be user-programmed with a simple BASIC-like programming language, enabling it to perform logic, conditioning, and other I/O processing in real time. On the Linux side, RIO comes with drivers and a function library to quickly configure and access the I/O and to exchange data with the Raspberry Pi.

The RIO features several communication interfaces, including an RS-232 serial port to connect to standard serial devices, a TTL serial port to connect to Arduino and other microcontrollers that aren’t equipped with a RS-232 transceiver, and a CAN bus interface.
The RIO is available in two versions. The RIO-BASIC costs $85 and the RIO-AHRS costs $175.

Roboteq, Inc.

High-Tech Halloween

Still contemplating Halloween ideas? Do you have a costume yet? Is your house trick-or-treat ready? Perhaps some of these high-tech costumes and decorations will help get you in the spirit.

Recent Circuit Cellar interviewee Jeremy Blum designed a creative and high-tech costume that includes 12 individually addressable LEDs, an Adafruit microcontroller, and 3-D printing.


Custom animatronic skull


Animatronic talking raven

Looking for Halloween decoration inspiration? Peter Montgomery designed some programmable servo animation controllers built around a Freescale Semiconductor 68HC11 microcontroller and a Parallax SX28 configurable controller.

Peter’s Windows-based plastic skull is animated with RC servos controlled via a custom system. It moves at 24 or 30 frames per second over a custom RS-485 network.
This animatronic talking raven features a machined aluminum armature and moves via RC servos. The servos are controlled by a custom system using Windows and embedded controllers.

Peter’s Halloween projects were originally featured in “Servo Animation Controller” (Circuit Cellar 188, 2006). He displays the Halloween projects every year.

Feeling inspired? Share your tech-based Halloween projects with us.

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?


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?


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?


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.


Designing Wireless Data Gloves

Kevin Marinelli, IT manager for the Mathematics Department at the University of Connecticut, recently answered CC.Post’s newsletter invitation to readers to tell us about their wearable electronics projects. Kevin exhibited his project,  “Wireless Data Gloves,” at the World Maker Faire New York in September. He spoke with Circuit Cellar Managing Editor Mary Wilson about the gloves, which are based on an Adafruit ATmega32U4 breakout board, use XBee modules for wireless communication, and enable wearers to visually manipulate data and 3-D graphics.

MARY: Tell us a little bit about yourself and your educational and professional background.

KEVIN: I am originally from Sydney, Nova Scotia, in Canada. From an early age I have

Kevin Marinelli

Kevin Marinelli

always been interested in taking things apart and creating new things. My degrees are a Bachelor’s in Computer Science from Dalhousie University in Halifax, Nova Scotia, and a Master’s in Computer Science from the University of New Brunswick in Fredericton, New Brunswick. I am currently working on my PhD in Computer Science at the University of Connecticut (UConn).

My first full-time employment was with ITS (the computer center) at Dalhousie University. After eight years, I moved on to an IT management position the Ocean Mapping Group at the University of New Brunswick. I am currently the IT manager for the Mathematics Department at  UConn.

I am also an active member of MakeHartford, which is a local group of makers in Hartford, Connecticut.

MARY: Describe the wireless data gloves you recently exhibited at the World Maker Faire in New York. What inspired the idea?

KEVIN: The idea was initially inspired 20 years ago when using a Polhemus 6 Degree-of-Freedom sensor for manipulating computer graphics when I was at the University of New Brunswick. The device used magnetic fields to locate a sensor in three-dimensional space and detect its orientation. The combined location and orientation data provides data with six degrees of freedom. I have been interested in creating six degrees of freedom input devices ever since. With the Arduino and current sensor technologies, that is now possible.

Wireless data gloves on display at World Maker Faire New York. (Photo: Rohit Mehta)

Wireless data gloves on display at World Maker Faire New York. (Photo: Rohit Mehta)

MARY: What do the gloves do? What applications are there? Can you provide an example of who might use them and for what purpose?

KEVIN: The data gloves allow me to use my hands to wirelessly transmit telemetry data to a base station computer, which collects the data and provides it to any application programs that need it.

There are a number of potential applications, such as manipulating 3-D computer graphics, measurement of data for medical applications, remote control of vehicles, remote control of animatronics and puppetry.

MARY: Can you tell me about the data gloves’s design and the components used?

KEVIN: The basic design guidelines were to make the gloves self-contained, lightweight, easy to program, wireless, and rechargeable. The main electronic components are an Adafruit ATmega32U4 breakout board  (Arduino Leonardo software compatible), a SparkFun 9d0f sensor board, an XBee Pro packet radio, a LiPo battery charger circuit, and a LiPo battery. These are all open hardware projects or, in the case of the battery, are ordinary consumer products.

The choice of the ATMega32U4 for the processor was made to provide a USB port without any external components such as an FTDI chip to convert between serial and USB communications. This frees up the serial port on the processor for communicating with the XBee radio.

For the sensors, the SparkFun 9dof board was perfect because of its miniscule size and

Top of glove

Top of glove

because it only requires four connections: two connections for power and two connections for I2C. The board has components with readily available data sheets, and there is access to working example code for the sensor board. This reduced the design work greatly by using an off-the-shelf product instead of designing one myself.

The choice of an 800-mAh LiPo battery provides an excellent lightweight rechargeable power supply in a small form factor. The relatively small battery powers the project for more than 24 h of continuous use.

Palm of glove

Palm of glove

A simple white cotton glove acts as the structure to mount the electronics. For user-controlled input, the glove has conductive fabric fingertips and palm. Touching a finger to the thumb, or the pad on the palm, closes an electrical pathway, which allows the microcontroller to detect the input.

For user-selectable input, each fingertip and the palm of the hand has a conductive fabric pad connected to the Adafruit microcontroller. The thumb and palm act as a voltage source, while the fingertips act as inputs to the microcontroller. This way, the microcontroller can detect which fingers are touching the thumb and the palm pads. Insulated wires of 30 gauge phosphor bronze are sewn into the glove to connect the pads to the microcontroller.

MARY: Are the gloves finished? What were some of the design challenges? Do you plan any changes to the design?

KEVIN: The initial glove design and second version of the prototype have been completed. The major design challenges were finding a microcontroller board with sufficient capabilities to fit on the back of a hand, and configuring the XBee radios. The data glove design will continue to evolve over the next year as newer and more compact components become available.

Initially I was designing and building my own microcontroller circuit based on the ATmega32U4, but Adafruit came out with a nice, usable, designed board for my needs. So I changed the design to use their board.

SparkFun has a well-designed micro USB-based LiPo battery charger circuit. This would have been ideal for my project except that it does not have an On/Off switch and only has some through-hole solder points for powering an external project. I used their CadSoft EAGLE files to redesign the circuit to make it slightly more compact, added in a power switch and a JST connector for the power output for projects.

The XBee radios were an interesting challenge on their own. My initial design used the standard XBee, but that caused communication complications when using multiple data gloves simultaneously. In reading Robert Faludi’s book Building Wireless Sensor Networks: With ZigBee, XBee, Arduino, and Processing, I learned that the XBee Pro was more suited to my needs because it could be configured on a private area network (PAN) with end-nodes for the data gloves and a coordinator for the base station.

One planned future change is to switch to the surface-mount version of the XBee Pro. This will reduce both the size and weight of the electronics for the project.

The current significant design challenge I am working on is how to prevent metal fatigue in the phosphor bronze wires as they bend when the hand and fingers flex. The fatigue problem occurs because I use a small diamond file to remove the Kapton insulation on the wires. This process introduces small nicks or makes the wires too thin, which then promotes the metal fatigue.

A third version is in the design stage. The new design will replace the SparkFun 9dof board with a smaller single-chip sensor, which I hope can be mounted directly on the Adafruit ATmega32U4 board.

MARY: What new skills or technologies did you learn from the project, if any?

KEVIN: Along the way to creating the gloves, I learned a great deal about modern electronics. My previous skills in electronics were learned in the ’70s with single-sided circuits with through-hole components and pre-made circuit boards. I can now design and create double-sided circuit boards with primarily surface-mounted components. For initial prototype designs, I use double-sided photosensitized circuit boards and etch them at home.

Learning to program Arduino boards and Arduino clones has been incredible. The fact that the boards can be programmed using C in a nice IDE with lots of support libraries for common programming tasks makes the platform an incredibly efficient tool. Having an enormous following makes it very easy to find technical support for solving problems with Arduino products and making Arduino clones.

Wireless networking is a key component for the success of the project. I was lucky to have a course in wireless sensor network design at UConn, which taught me how to leverage wireless technology and avoid many of the pitfalls. That, combined with some excellent reference books I found, insured that the networking is stable. The network design provides for more network bandwidth than a single pair of data gloves require, so it is feasible to have multiple people collaborating manipulating the same on the same project.

Designing microcontroller circuits using EAGLE has been an interesting experience. While most of the new components I use regularly in designs are available in libraries from Adafruit and SparkFun, I occasionally have to design my own parts in EAGLE. Using EAGLE to its fullest potential will still take some time, but I have become reasonably proficient with it.

For soldering, I mostly still use a standard temperature controlled soldering iron with a standard tip. Amazingly, this allows me to solder 0402 resistors and capacitors and up to 100 pitch chips. When I have components that need to be soldered under the surface, I use solder paste and a modified electric skillet. This allows me to directly control the temperature of the soldering and gives me direct access to monitoring the process.

The battery charger circuit on my data glove is hand soldered and has a number of 0402-sized components, as  well as a micro USB connector, which also is a challenge to hand solder properly.

MARY: Are there similar “data gloves” out there? How are yours different?

There are a number of data glove projects, which can be found on the Internet. Some are commercial products, while others are academic projects.

My gloves are unique in that they are lightweight and self-contained on the cotton glove. All other projects that you can find on the Internet are either hard-wired to a computer or have components such as the microcontroller, batteries, or radio strapped to the arm or body.

Also, because the main structure is a self-contained cotton glove; the gloves do not interfere with other activities such as typing on a keyboard, using a mouse, writing with a pen, or even drinking from a glass. This was quite handy when developing the software for the glove because I could test the software and make programming corrections without having the inconvenience of putting the gloves on and taking them off repeatedly.

MARY: Are you working on any other projects you’d like to briefly tell us about?

KEVIN: At UConn, we are lucky to have one of the few academic programs in puppetry in the US. In the spring, I plan on taking a fine arts course at UConn in designing and making marionette puppets. This will allow me to expand the use of my data gloves into controlling and manipulating puppets for performance art.

I am collaborating on designing circuit boards with a number of people in Hartford. The more interesting collaborations are with artists, where they think differently about technology than I do. Balam Soto of Open Wire Labs is a new media artist and one of the creative artists I collaborate with regularly. He is also a member of MakeHartford and presents at Maker Faires.

MARY: What was the response to the wireless data gloves at World Maker Faire New York?

KEVIN: The response to the data gloves was overwhelmingly positive. People were making comparisons to the Nintendo Power Glove and to the movie “Minority Report.” Several musicians commented that the gloves should be excellent for performing and recording virtual musical instruments such as a guitar, trumpet and drums.

For the demonstration, I showed a custom application; which allowed both hands (or two people) to interactively manipulate points and lines on a drawing. Many people were encouraged to use the gloves for themselves, which enhanced the quality of the feedback I received.

The gloves are large-sized to fit my hands, which was quite a challenge for younger children to use because their hands were “lost” in the gloves. Even with the size challenge, it was fun watching younger children manipulating the objects on the computer screen.

I look forward to the Maker Faire next year, when I will have implemented the newer design for the data gloves and will have additional software to demonstrate. I plan on trying to put together a presentation on some form of performance art using the data gloves.

Small Plug-In Embedded Cellular Modem

Skywire plug-in modem

Skywire plug-in modem

The Skywire is a small plug-in embedded cellular modem. It uses a standard XBee form factor and 1xRTT CDMA operating mode to help developers minimize hardware and network costs. Its U.FL port ensures antenna flexibility.

The Skywire modem features a Telit CE910-DUAL wireless module and is available with bundled CDMA 1xRTT data plans from leading carriers, enabling developers to add fully compliant cellular connectivity without applying for certification. Future versions of the Skywire will support GSM and LTE. Skywire is smaller than many other embedded solutions and simple to deploy due to its bundled carrier service plans.

Skywire is available with a complete development kit that includes the cellular modem, a baseboard, an antenna, a power supply, debug cables, and a cellular service plan. The Skywire baseboard is an Arduino shield, which enables direct connection to an Arduino microcontroller.

Skywire modems cost $129 individually and $99 for 1,000-unit quantities. A complete development kit including the modem costs $262.

NimbeLink, LLC

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 (www.jeremyblum.com/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.

Processing, Wiring, and Arduino (EE Tip 101)

Processing is a language and an open-source programming environment for programming images, animations, and interactions. The project, an initiative from Ben Fry and Casey Reas, is based on ideas developed by the Aesthetics and Computation Group of the MIT Media Lab. Processing was created in order to teach the fundamentals of programming in a visual context and to serve as a sketchbook or professional software production tool. Processing runs under GNU/Linux, Mac OS X, and Windows. Several books have already been written on Processing.

Source: Clemens Valens, “Microcontrollers for Dummes,” 080931-I, Elektor, 2/2009.

Source: Clemens Valens, “Microcontrollers for Dummes,” 080931-I, Elektor, 2/2009.

Just like Arduino, Wiring is a programming environment with microcontroller board for exploring electronic arts, teaching programming, and quick prototyping. Wiring, programmed in Processing, is an initiative by Hernando Barragán and was designed at the Interaction Design Institute Ivrea (IDII) in Italy.

Arduino is a fast, open-source electronic prototyping platform. Arduino is aimed at DIYers, electronics enthusiasts, and anyone interested in creating objects or interactive environments. Created by Massimo Banzi, Gianluca Martino, David Cuartielles, and David Mellis, Arduino uses a programming language based on Processing. Arduino may be regarded as a simplification of Wiring.

For more information, refer to Clemens Valens’s article, “Microcontrollers for Dummies,” 080931-I, Elektor, 2/2009.

CC278: Serial Displays Save Resources (BMP Files)

In Circuit Cellar’s September issue, columnist Jeff Bachiochi provides his final installment in a three-part series titled “Serial Displays Save Resources.” The third article focuses on bitmap (BMP) files, which store images.


A BMP file has image data storage beginning with the image’s last row. a—Displaying this data as stored will result in an upside-down image. b—Using the upsidedown=1 command will rotate the display 180°. c—The mirror=1 command flips the image horizontally. d—Finally, an origin change is necessary to shift the image to the desired location. These commands are all issued prior to transferring the pixels, to correct for the way the image data is stored.

LCDs are inexpensive and simple to use, so they are essential to many interesting projects, Jeff says. The handheld video game industry helped popularize the use of LCDs among DIYers.

Huge production runs in the industry “made graphic displays commonplace, helping to quickly reduce their costs,” Jeff says. “We can finally take advantage of lower-cost graphic displays, with one caveat: While built-in hardware controllers and drivers take charge of the pixels, you are now responsible for more than just sending a character to be printed to the screen. This makes the controllers and drivers not work well with the microcontroller project. That brings us to impetus for this article series.

“In Part 1 (‘Routines, Registers and Commands,’ Circuit Cellar 276, 2013), I began by discussing how to use a graphic display to print text, which, of course, includes character generation. In essence, I showed how to insert some intelligence between a project and the display. This intermediary would interpret some simple commands that enable you to easily make use of the display’s flexibility by altering position, screen orientation, color, magnification, and so forth.

“Part 2 (‘Button Commands,’ Circuit Cellar 277) revealed how touch-sensitive overlays are constructed and used to provide user input. The graphic display/touch overlay combination is a powerful combination that integrates I/O into a single module. Adding more commands to the interface makes it easier to create dynamic buttons on the graphic screen and reports back whenever a button is touched.

The prototype PCB I used for this project mounts to the reverse side of the thin-film transistor (TFT) LCD. The black connector holds the serial and power connections to your project. The populated header is for the Microchip Technology MPLAB ICD 3 debugger/programmer.

“Since I am using a graphic screen, it makes sense to investigate graphic files. This article (Part 3, ‘BMP Files,’ Circuit Cellar 277) examines the BMP file makeup and how this relates to the graphic screen.”

To learn more about the BMP graphical file format and Jeff’s approach to working with a graphic icon’s data, check out the September issue.


Q&A: Jack Ganssle, Electronics Entrepreneur

Jack Ganssle is a well-known engineer, author, lecturer, and consultant. After learning about oscilloscopes, transistors, and capacitors in his father’s engineering lab, Jack went on to write hundreds of articles and several books about embedded development-related topics. He also started and sold three electronics companies, worked on classified government projects, and founded The Ganssle Group, based in Reisterstown, MD. I recently spoke with Jack about some of his career highlights, his current work, and what’s next in the embedded design industry.—Nan Price, Associate Editor

NAN: You’ve been interested in electronics since the age of 9. Give us a little background information. What was your first project?

Jack Ganssle

Jack Ganssle

JACK: My first project was a crystal radio with the inductor wound on the quintessential Quaker oatmeal box! It was really exciting to get AM reception over that. Back then, pretty much no one had FM. AM was it.

Later I learned to repair TVs and made pocket money doing that. Those sets were all vacuum tubes. Usually there was just a bad tube or dried out capacitor. But from there, my friends and I learned to design amplifiers (the Beatles were very hot and everyone was starting a band). For graduation from eighth grade, my dad gave me an old oscilloscope he had built from a kit years earlier.

He was part of a startup when I was in my early teens. We kids were coerced into being the (unpaid) janitors for the place. That was annoying at first. But, we were allowed to keep anything we swept up. The engineering lab’s floor was always covered in resistors, capacitors, transistors, and the like, so my parts collection grew. (ICs existed then, but were rare.)

When I was 16 I got a ham license, built  various transmitters, and used WWII surplus receivers. One day an angry letter arrived from the Federal Communications Commission (FCC). They had picked me up on my second harmonic clear across the country. I was really proud of that contact.

But it wasn’t long before some resistor-transistor logic (RTL) digital ICs came my way. Projects included controls for tube transmitters, Estes model rocket telemetry, and even a crude TV camera that used a photomultiplier tube to scan a spiral set of holes in a spinning disk. A couple of us worked on a ham radio moon bounce, but I accidentally shorted out a resistor and my only hydrogen thyratron (sort of a tube version of an SCR) blew up. There was no money for a replacement, so that project died. The transmitter used a little lighthouse tube that had a maximum rating of a couple of watts, but it worked OK when pulsing it for a few microseconds at 1 kW.

Senior year of high school a friend and I hitchhiked from Maryland to Boston to go to a surplus store. I bought a core memory plane that was 13,000 bits in a 6 in2 cube. Long hair didn’t help. We were picked up on the New Jersey Turnpike and strip searched. The cops never believed my explanation that the thing was computer memory.

A few years later, I had a 6501 microprocessor in the glove compartment of my Volkswagen bus (which I lived in for a year while saving for a sailboat). Coming into a sleepy Maine town from Canada that event was repeated when the border cops searched the bus and found the chip. They didn’t believe in computers on a chip. But the PC was years away and computers were mostly seen in science fiction films.

Freshman year of college, I designed and built a 12-bit computer using hundreds of TTL chips soldered together using phone company wire on vectorboards. For I/O there was an old Model 15 teletype using 5-bit Baudot codes that my software drove via bit banging. The OS, such as it was, lived in a pair of 1702 EPROMs, which each held 256 bytes. The computer worked great! And then the 8008, the first 8-bit microcontroller, came out and the thing was obsolete. I junked it, and now I wish I had saved at least the schematics.

But by then I had been working part-time as an electronics technician for a few years and the company needed to update its analog products to digital. No one knew anything about computers, so they promoted me to engineer. Eventually I ran the digital group there. We designed one of the first floppy disk controllers, insanely high-resolution graphics controllers, and a lot of other products. We also integrated minicomputers (Data General Novas and DEC PDP-11s) into systems with microprocessors. We bought a 5-MB disk drive for a Nova. It cost $5,000 (back when that was a lot of money) and weighed 500 lb. How things have changed.

NAN: Tell us about The Ganssle Group (www.ganssle.com). When and why did you start the company? What types of services do you provide?

JACK:  I formed The Ganssle Group in 1997 after 15 years of running an in-circuit emulator company. Working 70 h a week was getting old and I wanted more time with my kids. So my objective was to reverse the usual model. Instead of fitting life around a job, I wanted to fit the job into life.

Goal 1: Four months of vacation a year. It turns out that is elusive, in no small part due to the cool stuff going on around here, but most years we do manage two to three months off. My wife, Marybeth, works with me. She takes care of all of the administrative/travel and the like.

Goal 2: No commute. So we work out of the house (for the first few years, we worked out of the houseboat where we raised two kids).

Now the kids are grown, so there’s a Goal 3: Have as much fun as possible with Marybeth, so when I travel to new or interesting places she often accompanies me. There’s a lot more to life than work. Some of my side projects are available at www.ganssle.com/jack.

I’m not really sure what I do. I write—a lot. Readers are incredibly smart and vocal. The dialogue with them is a highlight of my day. I also give one- and two-day seminars on pretty much every continent (except Antarctica—so far!) about ways to get better firmware done faster. Sometimes I do an expert witness gig. Those are always fascinating as one gets to dig deeply into products and learn about the law. On rare occasions, I’ll do a day or three of consulting if the problem is particularly interesting. And there’s always some experiment I’m working on, which sometimes gets written up as an article.

NAN: Speaking of articles, you’ve written hundreds—including nine for Circuit Cellar magazine—on topics ranging from the history of the embedded systems programming industry, to memory management, to using programmable logic devices (PLDs). You also write a column for Embedded (www.embedded.com) and you are editor of the biweekly newsletter The Embedded Muse. Tell us about the types of projects you enjoy constructing and writing about.

The breadboard is discharging batteries. To the left, a battery is soldered to some coax. Using the waveform generator in the oscilloscope I’m measuring the battery's reactance (which, it turns out, is entirely capacitive). The IAR tool is profiling current consumption of an evaluation board.

The breadboard is discharging batteries. To the left, a battery is soldered to some coax. Using the waveform generator in the oscilloscope I’m measuring the battery’s reactance (which, it turns out, is entirely capacitive). The IAR tool is profiling current consumption of an evaluation board.

JACK: I have one experiment that’s running right now. For the last four months I’ve been discharging coin cells. It sounds dull, but some microcontroller vendors are making outrageous claims about battery life that are on the surface true but irrelevant in real circuits. This circuit runs a complex profile on the batteries, tossing different loads on for a few milliseconds, and an ARM microcontroller samples the batteries’ voltage (as well as the transistors, VCE drop) into a log file. That data goes into a spreadsheet for further analysis. I’m making a much bigger version of this now, which will handle far more batteries at a time. I recently gave some preliminary results at a talk in Asilomar, CA, which garnered a lot of interest. More results will be forthcoming soon…I promise!

Another aspect of this is leakage. Does handling a battery leave finger oils that can affect the decades-long life claimed by the vendors? To test this, I built a femtoammeter. A polypropylene capacitor is charged and feeds a super-low bias current op-amp. Another ARM board monitors the op-amp voltage to watch the capacitor discharge as various contaminants are electrically connected to the capacitor. With no contaminants connected, even after 48 h, the cap discharged less than 1 mV. The thing resolves to better than 10 fA. (One fA is a millionth of a nanoamp, or about 6,000 electrons/second).

In fact, the ADC’s transfer function is a proxy for temperature. We heat the house with wood and you could see a perfect correlation of op-amp output and temperature throughout the day. (It’s lowest in the morning as the fire burns out overnight.)

NAN: You wrote the two-part Circuit Cellar article series, “Writing a Real-Time Operating System” (Issue 7 and 8, 1989) about the Hitachi HD64180 Z80-based embedded microprocessor nearly 15 years ago. Circuit Cellar also featured another HD64180-based article, “Huge Arrays on the HD64180: Taking Advantage of Memory Management” (Issue 16, 1990). What was your fascination with the HD64180? Also, is either of these projects still current? Have you changed any of the design components?

JACK: Gee, I have no idea. I wrote those using Microsoft Works, but the file format has changed and Works can no longer open those articles. Alas, the HD64180 is quite obsolete. It was a grown-up version of the Z80 and very popular in its day.

In 1974, Intel introduced the 8080, which was the first really decent 8-bit microprocessor. But it needed two clocks and three power supplies. The folks at Zilog came out with the Z80 a year later. It could run 8080 code, but had one clock, a single 5-V supply, and it offered additional instructions that massively improved code density. Intel responded with the 8085, but it was really an 8080 in drag. The couple of new instructions added just couldn’t give the Z80 a run for its money. Eventually Zilog came out with the Z180, and Hitachi the 64180 clone, which included on-board peripherals and a memory management unit to address 1 MB using standard Z80 instructions. It was a great idea, but since there was no on-board memory, it couldn’t compete with microcontrollers such as the ancient, and still-going-strong, 8051.

NAN: In addition to writing, you lecture and teach at conferences and symposiums worldwide. Tell us about your one-day “Better Firmware Faster” seminar. How did it begin? What can attendees expect to gain from it?

JACK: I’m completely frustrated with the state of firmware. It’s inevitably late and buggy. While there’s no doubt that crafting firmware is extremely difficult—after all, software is the most complex engineered product ever invented—we can and must do better. It’s astonishing that so few groups keep even the simplest metrics, yet engineering is all about numbers.

The seminar is a fast-paced event that shows developers better ways to get their code to market. It covers process issues, as well as a lot of technology areas unique to embedded systems, such as managing memory and dealing with tough real-time problems.

What can attendees get from it? It varies from very little to a lot. Some groups refuse to change anything, so will always maintain the status quo. Others do better. Some report 40% improvements to the schedule and up to an order of magnitude of reduction in shipped bugs.

NAN: You started three high-tech companies prior to The Ganssle Group. Tell us about your work experience. Any highlights?

JACK: Well, there was one instrument that used infrared light to measure protein in cow poop. Though it was interesting technology, it’s hard to call that a highlight. The design I’m most proud of was my first emulator, which had only 17 ICs and used insanely complex code. Eventually we offered emulators that required hundreds of chips, but those cost $7,000, while the first one sold for $600.

Some of the government work I’ve done was very interesting and used extremely sophisticated electronics. But I can’t talk about those projects. A buddy and I did the White House security system during the Reagan administration. It was fun to work in the basement there, but the bureaucracy was stifling. We lost our White House passes the same day Oliver North did, but he got more press.

NAN: What do you consider to be the “next big thing” in the embedded design industry? Is there a particular technology that you’ve used or seen that will change the way engineers design in the coming months and years?

JACK: Everything is going to change for us over the next five to 10 years. We will have tools that automatically find lots of bugs. Everyone is familiar (and has a love/hate relationship) with lint. But static analyzers can today find lots of runtime bugs. These are currently expensive and frustrating, but they demonstrate that such products can, and will, exist. When the issues are resolved, I expect they’ll be as common as IDEs. Debugging manually is hugely expensive.

Another tool is slowly gaining acceptance: so-called virtualization products (e.g., from Wind River and others). These are not the hypervisors people think about when using the word “virtualization.” Rather, they are complete software models of a target system. You can run all—and I mean all—of your code on the model. The hardware is always late. These tools will permit debugging to start at the beginning of the project. The tools are also expensive and somewhat clumsy, but will get better over time.

A modern smartphone has more than 10 million lines of code. Automobiles often have more. One thing is certain: Firmware will continue to grow in size and complexity. The current techniques we use to develop code will change as well.


Two-Channel CW Laser Diode Driver with an MCU Interface

The iC-HT laser diode driver enables microcontroller-based activation of laser diodes in Continuous Wave mode. With this device, laser diodes can be driven by the optical output power (using APC), the laser diode current (using ACC), or a full controller-based power control unit.

The maximum laser diode current per channel is 750 mA. Both channels can be switched in parallel for high laser diode currents of up to 1.5 A. A current limit can also be configured for each channel.

Internal operating points and voltages can be output through ADCs. The integrated temperature sensor enables the system temperature to be monitored and can also be used to analyze control circuit feedback. Logarithmic DACs enable optimum power regulation across a large dynamic range. Therefore, a variety of laser diodes can be used.

The relevant configuration is stored in two equivalent memory areas. Internal current limits, a supply-voltage monitor, channel-specific interrupt-switching inputs, and a watchdog safeguard the laser diodes’ operation through iC-HT.

The device can be also operated by pin configuration in place of the SPI or I2C interface, where external resistors define the APC performance targets. An external supply voltage can be controlled through current output device configuration overlay (DCO) to reduce the system power dissipation (e.g., in battery-operated devices or systems).

The iC-HT operates on 2.8 to 8 V and can drive both blue and green laser diodes. The diode driver has a –40°C-to-125°C operating temperature range and is housed in a 5-mm × 5-mm, 28-pin QFN package.

The iC-HT costs $13.20 in 1,000-unit quantities.

iC-Haus GmbH