Member Profile: Tom Freund

Tom Freund

Tom Freund

West Hartford, CT, USA

Tom has been a member for four years.

Tom says he enjoys machine learning; algorithm design; embedded, prognostic, and diagnostic systems; and eLua and C programming.

Tom recently bought a Femtoduino board and a Texas Instruments TMP102 sensor breakout board.

His current microcontrollers of choice are the STMicroelectronics STM32 32-bit ARM Cortex and Atmel’s ATmega328.

Tom is working on PicoDB, an open-source, NoSQL database tool for 32-bit microcontrollers written in Lua. (To learn more, visit

Tom says when he thinks about embedded technology’s future, just one phrase comes to mind: “the Internet of things.”

“In 10 to 15 years time, we will look back and think of Facebook, Twitter, and (yes) even Google as the ’Model T’ days of global networking,” he says. “That is because everything will be connected to everything at various levels of security. We and our infrastructure will be ’minded’ by unseen digital butlers that help us cope with life and its unpredictability, as well as protect that which should be kept private.”

3-D Printing with Liquid Metals

by Collin Ladd and Michael Dickey

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

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

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

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


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

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

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

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

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

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

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

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




PWM Controller Uses BJTs to Reduce Costs

Dialog iW1679 Digital PWM Controller

Dialog iW1679 Digital PWM Controller

The iW1679 digital PWM controller drives 10-W power bipolar junction transistor (BJT) switches to reduce  costs in 5-V/2-A smartphone adapters and chargers. The controller enables designers to replace field-effect transistors (FETs) with lower-cost BJTs to provide lower standby power and higher light-load and active average efficiency in consumer electronic products.

The iW1679 uses Dialog’s adaptive multimode PWM/PFM control to dynamically change the BJT switching frequency. This helps the system improve light-load efficiency, power consumption, and electromagnetic interference (EMI). The iW1679 provides high, 83% active average efficiency; maintains high efficiency at loads as light as 10%. It achieves less than 30-mW no-load standby power with fast standby recovery time. The controller meets stringent global energy efficiency standards, including: US Department of Energy, European Certificate of Conformity (CoC) version 5, and Energy Star External Power Supplies (EPS) 2.0.

The iW1679 offers a user-configurable, four-level cable drop compensation option. It comes in a standard, low-cost, eight-lead SOIC package and provides protection from fault conditions including output short-circuit, output overvoltage, output overcurrent, and overtemperature.

The iW1679 costs $0.29 each in 1,000-unit quantities.

Dialog Semiconductor

MIT’s Self-Assembling Robots

Calling it a low-tech solution to a high-tech challenge, MIT researchers have received a lot of attention recently for their modular system of self-assembling robot cubes. The video of the so-called M-Blocks in action, which MIT posted earlier this month on YouTube, has also become high profile. A recent tally has the video at nearly 1.5 million views and counting.


The text accompanying the video explains how the cubes are able to move around and climb over each other,  jump into the air, and roll across surfaces as they connect in a variety of configurations. And they do all this without any external moving parts. Instead, each M-Block contains a flywheel that can reach speeds of 20,000 rpm. When the flywheel brakes, it imparts angular momentum to the cube.  Precisely placed magnets on every face and edge of each M-Block enable any two cubes to attach to each other.

The simple design holds short- and long-term promise.  According  to an October 4 article by Larry Hardesty of the MIT News Office, it is hoped that the blocks can be miniaturized someday, perhaps to swarming microbots that can self-assemble with a purpose. Even at their current size, further development of the M-Blocks might lead to “armies of mobile cubes” that can help repair bridges and buildings in emergencies, raise scaffolding, reconfigure into heavy equipment or furniture as needed, or head in to environments hostile to humans to diagnose and repair problems, the article suggests.

While it may not rise to “cooperative group behavior,”  the ability of one cube to drag another and influence its alignment is impressive. What could 100 or more of these robots accomplish as MIT researchers continue to develop algorithms to control them?

A prototype of the new modular robot, with its flywheel exposed. (Photo: M. Scott Brauer)

A prototype of the new modular robot, with its interior and flywheel exposed.
(Photo: M. Scott Brauer)

Client Profile: Pico Technology

Pico Technology
320 North Glenwood Boulevard
Tyler, TX 75702


Embedded Products/Services: Pico Technology’s PicoScope 5000 series uses reconfigurable ADC technology to offer a choice of resolutions from 8 to 16 bits. For more information, visit

PicoProduct information: The new PicoScope 5000 series oscilloscopes have a significantly different architecture. High-resolution ADCs can be applied to the input channels in different series and parallel combinations to boost the sampling rate or the resolution.

In Series mode, the ADCs are interleaved to provide 1 GB/s at 8 bits. In Parallel mode, multiple ADCs are sampled in phase on each channel to increase the resolution and dynamic performance (up to 16 bits).

In addition to their flexible resolution, the oscilloscopes have ultra-deep memory buffers of up to 512 MB to enable long captures at high sampling rates. They also feature standard, advanced software, including serial decoding, mask limit testing, and segmented memory.

The PicoScope 5000 series oscilloscopes are currently available at

The two-channel, 60-MHz model with built-function generator costs $1,153. The four-channel, 200-MHz model with built-in arbitrary waveform generator (AWG) costs $2,803. The pricing includes a set of matched probes, all necessary software, and a five-year warranty.

Kevin Hannan Wins the CC Code Challenge (Week 19)

We have a winner of last week’s CC Weekly Code Challenge, sponsored by IAR Systems! We posted a code snippet with an error and challenged the engineering community to find the mistake!

Congratulations to Kevin Hannan of Marietta, Georgia, USA for winning the CC Weekly Code Challenge for Week 19! Kevin will receive a CCGold Issues Archive.

Kevin’s correct answer was randomly selected from the pool of responses that correctly identified an error in the code. Kevin answered:

Line 17: WHERE should be HAVING


You can see the complete list of weekly winners and code challenges here.

What is the CC Weekly Code Challenge?
Each week, Circuit Cellar’s technical editors purposely insert an error in a snippet of code. It could be a semantic error, a syntax error, a design error, a spelling error, or another bug the editors slip in. You are challenged to find the error.Once the submission deadline passes, Circuit Cellar will randomly select one winner from the group of respondents who submit the correct answer.

Inspired? Want to try this week’s challenge? Get started!

Submission Deadline: The deadline for each week’s challenge is Sunday, 12 PM EST. Refer to the Rules, Terms & Conditions for information about eligibility and prizes.

Dual-Channel Waveform Generators

B&K Precision 4053 Waveform Generator

B&K Precision 4053 Waveform Generator

The 4050 Series is a new line of four dual-channel function/arbitrary waveform generators. The instruments can generate 5-to-50-MHz waveforms for applications requiring stable and precise sine, square, triangle, and pulse waveforms with modulation and arbitrary waveform capabilities.

All models provide a main output voltage that can be vary from 0 to 10 VPP into 50 Ω and a secondary output that can vary from 0 to 3 VPP into 50 Ω. The generators feature a 3.5” color LCD, a rotary control knob, and a numeric keypad with dedicated waveform keys and output buttons.

The 4050 Series provides users with 48 built-in arbitrary waveforms. Using the included waveform editing software via the standard USB interface on the rear, users can create and load up to 10 custom 16-kpt waveforms. For general-purpose interface bus (GPIB) connectivity, an optional USB-to-GPIB adapter is available.

The generators offer a variety of modulation schemes for modulated signal applications including amplitude and frequency modulation (AM/FM), double sideband amplitude modulation (DSB-AM), amplitude and frequency shift keying (ASK/FSK), phase modulation (PM), and pulse-width modulation (PWM). Additional standard features include a linear and logarithmic sweep function, a built-in counter, sync output, a trigger I/O terminal, and a USB host port on the front panel to save and recall instrument settings and waveforms. A standard external 10-MHz reference clock input is provided to synchronize the instrument to another generator.

The 4052 (5-MHz) costs $499, the 4053 (10 MHz) costs $599, the 4054 (25 MHz) costs $850, and the 4055 (50 MHz) costs $1,050. Note: B&K Precision is offering 10% off MSRP through November 30, 2013. See website for details.

B&K Precision Corp.

Electrical Engineering Crossword (Issue 279)

The answers to Circuit Cellar’s October electronics engineering crossword puzzle are now available.



1.    ERASABLE—The second “E” in EEPROM
4.    NYCRESISTOR—Brooklyn, NY-based open-community workspace [two words]
5.    WHITEHAT—A hacker with ethics may don one of these [two words]
6.    WIMAX—aka, IEEE 802.16
8.    STRUCTUREDQUERY—A type of data-management language [two words]
9.    PACKETSWITCHING—Data grouping method [two words]
11.    VOLTOHMMETER—Capable of measuring  voltage, current, and resistance [three words]
12.    ELUA—It’s free, open source, and embedded
13.    BUCK—A switched-mode power supply converter
14.    GOODPUT—This can be calculated by dividing a transmitted file’s size by the amount of time it takes to transfer the file
16.    GRAYCODE—One bit makes a difference [two words]
17.    UBUNTU—Linux-based OS
18.    WEARLEVELING—When applied to a flash memory, this technique can level out the amount of writes to any given memory block across the entire memory chip [two words]
19.    MOODLE—E-learning software developed by Australian computer scientist Martin Dougiamas
20.    CROSSEDFIELD—This type of microwave amplifier can also be used as an oscillator [two words]


2.    LONGTERMEVOLUTION—Wireless communication standard [three words]
3.    CHEMILUMINESCENCE—A chemical reaction that creates a light emission
7.    BAXANDALL—A negative-feedback circuit used in high-quality audio amplifiers
15.    PAUSEUS—BASIC command that creates a microsecond-based delay


SRPP Headphone Amp (EE Tip #106)

Mention tube amplifiers and many designers go depressive instantly over the thought of a suitable output transformer. The part will be in the history books forever as esoteric, bulky and expensive because, it says, it is designed and manufactured for a specific tube constellation and output power. There exist thick books on tube output transformers, as well as gurus lecturing on them and winding them by hand. However, with some concessions to distortion (but keeping a lot of money in your pocket) a circuit configuration known as series regulated push-pull (SRPP) allows a low-power tube amplifier to be built that does not require the infamous output transformer. SRPP is normally used for pre-amplifier stages only, employing two triodes in what looks like a cascade arrangement.

Here we propose the use of two EL84 (6BQ5) power pentodes in triode SRPP configuration. The reasons for using the EL84 (6CA5) are mainly that it’s cheap, widely available ,and forgiving of the odd overload condition. Here, two of these tubes are SRPPed into an amplifier that’s sure to reproduce that ‘warm thermionic sound’ so much in demand these days.

Martin Louw Kristoffersen, Elektor, 081151-I, 7-8/2009

Martin Louw Kristoffersen, Elektor, 081151-I, 7-8/2009

Before describing the circuit operation, it must be mentioned that construction of this circuit must not be attempted unless you have experience in working with tubes at high voltages, or can rely on the advice and assistance of an “old hand.” As a safety measure, two anti-series connected Zener diodes are fitted at the amplifier output. These devices protect the output (i.e., your headphones and ears) against possibly dangerous voltages at switch-on, or when output capacitor C3 breaks down.

The power supply is sized for two channels (i.e., a stereo version of the amplifier). The values in brackets are for Elektor readers on 120-V AC networks. Note the doubled values of fuses F1 and F3 in the AC primary circuits. The PSU is a conventional design, possibly with the exception of the 6.3-V heater voltage being raised to a level of about +80 V through voltage divider R7-R8. This is done to prevent exceeding the maximum cathode heater voltage specified for the EL84 (6CA5). R6 is a bleeder resistor emptying the reservoir capacitors C8 and C9 in a quick but controlled manner when the amplifier is switched off. Rectifier diodes D3–D6 each have an anti-rattle capacitor across them.

In the amplifier, assuming the tubes used have roughly the same emission, the half-voltage level of about +145 V exists at the junction of the anode of V1 and the control grid of V2. The SRPP is no exception to the rule that high quality, (preferably) new capacitors are essential not just for reproduction and sound fidelity, but also for safety.

—Martin Louw Kristoffersen, Elektor, 081151-I, 7-8/2009

Workspace for Coding and Control System Development

Not every engineer’s workspace includes a recliner and a Chihuahua—but this setup works for David Cass Tyler, a retired embedded systems engineer from Willard, NM. Tyler’s “work environment” enables him to “do things at his own pace.”


“This is my normal working environment,” Tyler said. “My assistant is a 3-year-old Chihuahua that believes he is essential for me to correctly code.”

Tyler explained his work setup via e-mail:

When I require extra space to spread out, I move into the spare bedroom and use the desk in there to set up the hardware.

Almost all of my projects are developed to be distributed and accessible through the network. When I need to program on a different computer, I tend to use the remote desktop to program on other Windows-based systems. There is seldom a time when I have to physically move to one of the other systems, so this keeps my dog happy.


Tyler’s 256 I/O channel hardware simulator is shown. “This 24-VDC system has enough channels to comfortably simulate the hardware of almost any of my projects,” he explained.

Tyler is currently working on a 256 I/O channel hardware simulator. He says the PC/104 hardware stack gives him 256 channels of I/O, including 64 analog inputs, 24 analog outputs, and 168 digital I/Os, all in a single compact stack.

He provided some background detail about the system:

In 1995, I was a supervisor with ATK. I designed and had my crew build this system to provide hardware inputs to a control system we were developing for a government customer. I personally programmed the base system and others in my crew used it to develop the hardware simulator.

We also had a 3U 19” rack-mounted box that contained six Rabbit Semiconductor BL2100s, which were the actual controllers used in the system. They enabled us to build the control system before the actual hardware being controlled was delivered. This was the only time in my 30-plus year career that the system was delivered, the controllers were hooked up, and the system ran right out of the box. Of course we had some tweaking and tuning to do, but the system came up under control. There were subsystems that were potentially dangerous to human life, but, with the controllers in place, we were able to safely start up without hurting anyone and without breaking expensive custom equipment.

CassTylerBottom of Canister

The system connectors to Tyler’s 256-channel hardware system are shown.

Tyler also listed some advantages to using the system:

  • You can build the control system without having possession of the actual system.
  • During code coverage and fault testing, you can simulate faults that would be expensive or dangerous to test otherwise.
  • You can continue to develop components after the actual system has been delivered.
  • When writing the simulator, you can understand the interactions better and more completely.
  • You can do virtually all of the training on the simulator, using the exact actual software that will be delivered to the customer.
  • You can respond to many customer requests without having be present at the customer’s site.
CassTyler1553 Box

Tyler’s 1553 system

Tyler’s “workspace” includes several development systems from Rabbit Semiconductor and NetBurner as well as Microchip Technology PIC microcontrollers. He also has a MIL-STD-1553 system with a bus controller and a remote terminal, both controlled by Advantech PCM-3350 CPUs.

Tyler described some of his projects by saying:

I use a combination of hardware and software simulation to develop my control systems. Using hardware simulation, you can feed expected values to controllers to calibrate them and check their functionality. Using software-only functionality, you can develop systems anywhere. With virtual computers, you can test control systems distributed between multiple “computers.” Using this technique, you can deliver control systems, ready for final debugging, at the same time the system hardware is delivered—all from the comfort of your easy chair.

He provided a final thought about built-in web servers:

You can now embed web servers that enable you to run your system without installing anything on the user’s system. With ample available storage, you can put all the datasheets, manuals, and data files directly on the embedded controllers so they are always available, even without an Internet connection. Usually, you can also put some degree of manual control on the web server so you can perform at least rudimentary diagnostics and control.

Tyler is the owner and author of The Control Freak, which he uses to share back to the community. His is currently working on a Standard Commands for Programmable Instruments (SCPI) parser.

Tyler recently wrote a two-part article about Calibration. Part 1 will appear in Circuit Cellar’s November issue.


Battery Basics (Part 2): Battery Back-Up Power

Circuit Cellar columnist George Novacek has been “burned” more than once by manufacturers of battery-powered devices that include chargers poorly suited for the batteries required.

To get the full life out of a rechargeable battery, the charger must be “specifically designed” for the battery type, Novacek says in his October issue column “Battery Basics (Part 2): Battery Back-Up Power.”

The charger schematic diagram is shown.

The charger schematic diagram is shown.

When cordless phone, lawn mower, or power tool batteries die before their time, it gets expensive.

“The replacement cost of battery packs in my equipment represents about 50% of the equipment’s purchase price,” Novacek says. “Consequently, I would have expected the supplied or built-in chargers to be optimized for the batteries. Unfortunately, this is just wishful thinking. I have spent a fortune on replacement power packs for several of my battery-operated devices.”

Novacek’s column discusses what causes short battery life, how to purchase the right charger, and tips on building your own charger.

“As an engineer, if I can’t buy what I need or have been burned by commercial,off-the-shelf equipment, I design my own solution to the problem,” he says. “Building a good battery charger is easy these days because many ICs are specifically designed for battery chargers.

“The plethora of available ICs—together with exhaustive application notes—enables you to design a charger with minimal external parts for almost any battery type. The resulting circuits are often small enough to fit inside enclosures of your original, poorly designed chargers.”

You can also build a good charger out of parts found in your component box, Novacek says. In fact, he did just that when he needed a reliable floating backup power source for the fans of his home’s gas-fired Franklin stove. “I selected two 12-V/7-Ah sealed lead-acid batteries connected in parallel. They are widely available, reasonably priced, and have adequate capacity for my needs. I also built the charger with components I had lying around my workbench.”

Photo 1: The charger is built on a small piece of a perforated board. An ample heatsink is needed during constant current mode. The six-pin header on the right side is used to in-circuit program the Atmel ATtiny85 microcontroller.

Here is a small portion of his description the charger design.

Figure 1 shows the charger schematic diagram… Series regulator U1, a Texas Instruments LM117 adjustable regulator, works as a current source with R4 determining the 1.5-A current. When the battery voltage reaches 14.5 to 14.7 V, MOSFET Q1 is turned on, changing U1 to a constant voltage source. Potentiometer R1 trims the voltage to 13.6 V, which is crucial for long battery life.

“U2 is a 5-V regulator that feeds the microcontroller U3, an Atmel ATtiny85, which monitors the charger’s status and switches between the operating modes. Zener diodes D7 and D8 and signal diodes D9, D10, and D11 together with JFET Q3 serve as a level shifter to monitor the battery voltage. They subtract 10.5 V from the battery voltage to place it within the 5-V input range of the ATtiny’s ADC.JFET Q3 ensures constant current through the diodes and the voltage drop across the diodes is essentially independent of the battery voltage.”

Photo 1 shows the charger construction. “The header at the right-hand edge is for the ATtiny85’s in-circuit programmer,” he says. “Also, notice that the ATtiny85 inputs are protected by Schottky diodes and 10-kΩ series resistors to prevent its input pins’ excursion beyond 5 V.”

Novacek’s column goes on to explain how you can change a few components of the charger to make it work with different lead-acid battery types.

For those details and others, check out Novacek’s full column in the October issue.


PC-Programmable Temperature Controller

Oven Industries 5R7-388 temperature controller

Oven Industries 5R7-388 temperature controller

The 5R7-388 is a bidirectional temperature controller. It can be used in independent thermoelectric modules or in conjunction with auxiliary or supplemental resistive heaters for cooling and heating applications. The solid-state MOSFET output devices’ H-bridge configuration enables the bidirectional current flow through the thermoelectric modules.
The RoHS-compliant controller is PC programmable via an RS-232 communication port, so it can directly interface with a compatible PC. It features an easily accessible communications link that enables various operational mode configurations. The 5R7-388 can perform field-selectable parameters or data acquisition in a half duplex mode.

In accordance with RS-232 interface specifications, the controller accepts a communications cable length. Once the desired set parameters are established, the PC may be disconnected and the 5R7-388 becomes a unique, stand-alone controller. All parameter settings are retained in nonvolatile memory. The 5R7-388’s additional features include 36-VDC output using split supply, a PC-configurable alarm circuit, and P, I, D, or On/Off control.

Contact Oven Industries for pricing.

Oven Industries, Inc.

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

Jeremy Blum

Jeremy Blum

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

NAN: When did you start working with electronics?

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

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

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

DeepNote Guitar Hero Robot

DeepNote Guitar Hero Robot

Mineral Oil-Cooled Computer

Mineral Oil-Cooled Computer

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

Cornell University's PopShop

Cornell University’s PopShop

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

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

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

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

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

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


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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Here are some highlights from my teaching work:


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

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

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

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

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

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


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

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

Laurent Haas Wins the CC Code Challenge (Week 18)

We have a winner of last week’s CC Weekly Code Challenge, sponsored by IAR Systems! We posted a code snippet with an error and challenged the engineering community to find the mistake!

Congratulations to Laurent Haas of Paris, France for winning the CC Weekly Code Challenge for Week 18! Laurent will receive an IAR Kickstart: KSK-LPC4088-JL.

Laurent’s correct answer was randomly selected from the pool of responses that correctly identified an error in the code. Laurent answered:

Line 19 : Should be “write(*,*) average”


You can see the complete list of weekly winners and code challenges here.

What is the CC Weekly Code Challenge?
Each week, Circuit Cellar’s technical editors purposely insert an error in a snippet of code. It could be a semantic error, a syntax error, a design error, a spelling error, or another bug the editors slip in. You are challenged to find the error.Once the submission deadline passes, Circuit Cellar will randomly select one winner from the group of respondents who submit the correct answer.

Inspired? Want to try this week’s challenge? Get started!

Submission Deadline: The deadline for each week’s challenge is Sunday, 12 PM EST. Refer to the Rules, Terms & Conditions for information about eligibility and prizes.

Maker Faire in Rome Highlights Big News For Arduino Fans

If you like working on Arduino projects, you probably welcome some big news on two Linux-capable boards that came out of the recent Maker Faire in Rome.

Arduino founder Massimo Banzi announced a new collaboration with Intel called the Intel Galileo, an Arduino-compatible microcontroller board that uses Intel’s 32-bit Pentium-class




With the Galileo’s small, 32-bit Quark processor, the collaboration gives Intel a toehold in the low-power device market, while providing Arduino-compatible boards that have more processing power. (Arduino devices currently use Atmel’s 8-bit microcontrollers.)

An October 3 Arduino blog post by Zoe Romano says the Galileo is “a great tool for quickly prototyping simple interactive designs like LED light displays that respond to social media, or for tackling more complex projects from automating home appliances to building life-size robots that you control from your smartphone.”

Also at the Maker Faire, Banzi and Texas Instruments spokesmen discussed their collaboration on Arduino TRE, a next-generation Arduino SBC based on TI’s Sitara AM335x ARM Cortex-A8 processor.

Arduino TRE is the “most powerful Arduino to date” and will be able to run full Linux, according to another Arduino blog post by Romano.

“Arduino developers will get up to 100 times more performance with the Sitara-processor-based TRE than they do on the Arduino Leonardo or Uno,”  Romano says. For example, the Linux Arduino will be able to run high-speed communications and high-performance desktop applications.

Intel may be closely  following  news about the Arduino TRE, Stephen Shankland suggests in his October 5 article on the c/net website.

“The Arduino Tre speed boost comes from its Texas Instruments Sitara AM335x processor, which is based on the Cortex-A8 design from ARM Holdings,” Shankland’s article says. “Because ARM chips are nearly universal in the smartphone market that Intel has been struggling to penetrate, they’re a top competitive concern for Intel, and TI’s move means it might not be Intel’s Pentium-derived Quark chips that hobbyists end up with when looking for their next widget.”

However the competition plays out, it all seems nothing but good news for electronics tinkerers, hardware hackers, hobbyists, and designers who want more choices and more processing power for their Arduino-based projects.