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.

AAR Arduino Autonomous Mobile Robot

The AAR Arduino Robot is a small autonomous mobile robot designed for those new to robotics and for experienced Arduino designers. The robot is well suited for hobbyists and school projects. Designed in the Arduino open-source prototyping platform, the robot is easy to program and run.

The AAR, which is delivered fully assembled, comes with a comprehensive CD that includes all the software needed to write, compile, and upload programs to your robot. It also includes a firmware and hardware self test. For wireless control, the robot features optional Bluetooth technology and a 433-MHz RF.

The AAR robot’s features include an Atmel ATmega328P 8-bit AVR-RISC processor with a 16-MHz clock, Arduino open-source software, two independently controlled 3-VDC motors, an I2C bus, 14 digital I/Os on the processor, eight analog input lines, USB interface programming, an on-board odometer sensor on both wheels, a line tracker sensor, and an ISP connector for bootloader programming.

The AAR’s many example programs help you get your robot up and running. With many expansion kits available, your creativity is unlimited.

Contact Global Specialties for pricing.

Global Specialties

LED Characterization: An Arduino-Based Curve Tracer

Circuit Cellar columnist Ed Nisley doesn’t want to rely solely on datasheets to understand the values of LEDs in his collection. So he built a curve tracer to measure his LEDs’ specific characteristics.

Why was he so exacting?

“Most of the time, we take small light-emitting diodes for granted: connect one in series with a suitable resistor and voltage source, it lights up, then we expect it to work forever,” he says in his July column in Circuit Cellar. “A recent project prompted me to take a closer look at commodity 5-mm LEDs, because I intended to connect them in series for better efficiency from a fixed DC supply and in parallel to simplify the switching. Rather than depend on the values found in datasheets, I built a simple Arduino-based LED Curve Tracer to measure the actual characteristics of the LEDs I intended to use.”

The Arduino Pro Micro clone in this hand-wired LED Curve Tracer controls the LED current and measures the resulting voltage.

Ed decided to share the curve tracer with his Circuit Cellar readers.

“Even though this isn’t a research-grade instrument, it can provide useful data that helps demonstrate LED operation and shows why you must pay more attention to their needs,” he says.

Ed says that although he thinks of his circuit as an “LED Curve Tracer,” it doesn’t display its data.

“Instead, I create the graphs with data files captured from the Arduino serial port and processed through Gnuplot,” he says. “One advantage of that process is that I can tailor the graphs to suit the data, rather than depend on a single graphic format. One disadvantage is that I must run a program to visualize the measurements. Feel free to add a graphics display to your LED Curve Tracer and write the code to support it!”

He adds that “any circuit attached to an Arduino should provide its own power to avoid overloading the Arduino’s on-board regulator.”

“I used a regulated 7.5 VDC wall wart for both the Arduino Pro Mini board and the LED under test, because the relatively low voltage minimized the power dissipation in the Arduino regulator,” he says. “You could use a 9 VDC or 12 VDC supply.”

To read more about Ed’s curve tracer, check out Circuit Cellar’s July issue.


ALTspace – Cubes, Shame and Art

ALTSpace is a Community Art Workshop in Seattle. Creative people of all kinds share this spacious workshop, teaching, experimenting, making and learning. Members can spend time bouncing ideas off one another, hold or attend classes, work away from home and have the space to get even large projects done.

Location 2318 E. Cherry Street, Seattle, WA
Members 37

ALTspace hackerspace, Seattle

Co-founder Mike tells us about his space:
Tell us about your meeting space!

We have a total of about 2800 sq ft. We have two garage spaces for industrial machines, loud and dirty operations. (about 700 sq ft total) The rest of the space is for personal workspaces and public areas for working, meeting, hanging out. We have 2 showers, 2 bathrooms, a kitchen, a laundry room and an outdoor patio.

What tools do you have in your space? (Soldering stations? Oscilloscopes? 3-D printers?)

Full list of ALTspace’s tools & equipment.

Are there any tools your group really wants or needs?

A laser cutter would be our next purchase.

Does your group work with embedded tech (Arduino, Raspberry Pi, embedded security, MCU-based designs, etc.)?

Yes, we do quite a bit of electronics. One of our more well known projects, the Groovik’s Cube (A 30ft playable Rubik’s Cube) is an arduino driven project.

Can you tell us about some of your group’s recent tech projects?

Groovik’s Cube:

ALTspace's Groovik's CubeWe first built the cube as an art project for Burning Man 2009 and we’ve since been working hard to try and bring this project to the general public. We’ve been collaborating with the Science Center since summer ’10 and we’ve been doing a number of refurbishments including a brand new light-weight aluminum structure to create a neater look suitable for an indoor museum environment.

Groovik’s cube is a fully playable, LED driven Rubik’s cube, hung from the ceiling, corner down. (the motion is of course simulated, not mechanical, i.e. the colors move around, not the structure itself). It can be played and solved by the visitors. A particularly interesting feature is that we have split the controls into 3 stations placed around the cube, each allowing only one axis of rotation. This means 3 people have to collaborate together to solve it. The stations are ~30-50 ft apart from each other. This makes the puzzle considerably harder with a current record solution time of 50 minutes (achieved on Friday night @ Burning Man 09). It also turns a very introverted game into a collaborative challenge which is fun to watch. Imagine people shouting instructions to each other and running around checking on the state of the cube from different angles.

Temple of Shame:

ALTspace's Temple of Shame

by Alissa Mortenson, Nebunele Theatre, The Temple of Shame was a 6ft wide, 18ft tall wooden Temple dedicated to the collection of shame from the participants of Black Rock City. The temple was ceremonially burned on the last night of the festival to symbolically release all the shame collected.

From “The experience of shame is part of our shared humanity, yet paradoxically, the times when we are ashamed are the times when we feel most alone. But within shame lies a capacity for human connection. The Shame Bearers seek to explore this emotion as a powerful medium for reaching a state of shared vulnerability. In order to make connection –the core human desire– we must believe that we are enough, that we are worthy of love and acceptance. In our vulnerability and our recognition of our mutual imperfections, we can find worthiness and connection. That is the power of this project.”

What’s the craziest project your group or group members have completed?

Groovik’s cube for sure.

Do you have any events or initiatives you’d like to tell us about? Where can we learn more about it?

Indeed: We’re trying to raise funding for a new Groovik’s cube that will travel the World for 7 years together with Liberty Science Center and Erno Rubik!

What would you like to say to fellow hackers out there?

Hack more! Not satified with availability of hackerspaces near you ? Start one! It’s easier than you think and people come out of the woodwork to come and help and donate time and tools.

ALTspace’s tools & equipment:


  • 2HP Metal Mill & Lathe
  • Lincoln 220 MIG Welder (up to 1/4″ steel)
  • TIG 200Amp DC/AC (i.e. Steel, Aluminum & other non-ferrous)
  • Plasma Torch (Up to 1″ steel or aluminum)
  • Stick Welder
  • Metal Grinding wheels, belt sanders
  • 4×6 Metal Bandsaw
  • Deburring wheel and 2 buffers
  • Wire bender
  • Abrasive metal chop saw

Machine Shop (Wood):

  • 3/4HP Table saw
  • Router table & Hand Router
  • Various Sanders (Orbital & Belt)
  • Miter Chop saw

Other Machine Shop amenities:

  • 90 PSI Compressor
  • 3/4HP 1/2″ Shank Drill press
  • Hand drills, Sander
  • 110V/230V Power (50A)


  • Glass fusing/slumping/casting kiln, up to 1600 deg F

Jewelery setup:

  • Small Propane/Oxygen torch for soldering/annealing
  • Flexshaft Rotary grinder
  • Rolling Mill
  • Disc Die Cutter & Hemisphere punch

Electronics benches:

  • Maker bot
  • Soldering station with fume extractor and static pad
  • Multimeter
  • 100 Mhz Oscilloscope (Techronix)
  • Basic tools (snippers, strippers, screwdrivers, etc)
  • Variable voltage / current power supply
  • Stock of common components
  • Anti-static worktop

Sewing Area:

  • Pfaff industrial sewing machine
  • Janome domestic sewing machine
  • Hoseki HK757G is a 5-thread industrial serger
  • White domestic 4-thread serger
  • irons, cork-topped layout table, digitizing table, pattern plotter
  • Janome Computerized domestic sewing machine
  • Rowenta domestic iron
  • Sleeve board
  • Tailor’s ham
  • Pattern Drafting Rulers and curves
  • Costuming books

Read more about ALTspace’s Groovik’s Cube project on indiegogo or on Mike’s website, or about The Shame Project on!

You can read about more of ALTspace’s projects on their art page.

Show us your hackerspace! Tell us about your group! Where does your group design, hack, create, program, debug, and innovate? Do you work in a 20′ × 20′ space in an old warehouse? Do you share a small space in a university lab? Do you meet at a local coffee shop or bar? What sort of electronics projects do you work on? Submit your hackerspace and we might feature you on our website!

Ace Monster Toys – 3D Printing, DIY Book Scanners and “Dirty Shops”

Ace Monster Toys is a Hackerspace in the East San Francisco Bay Area dedicated to education, hacking, and maker culture since September 2010. They are a membership based group with regular free open-to-the-public classes and events. They are open to anyone and non-members are welcome.

Location 6050 Lowell Street, Oakland, CA
Members 55

Ace Monster Toys Hackerspace

Here’s what Ace Monster Toys member David has to say about his group:
Tell us about your meeting space!

Our space is 1600 sq ft, divided among three rooms, one upstairs and two downstairs. The upstairs is the “less dirty” area, with desks for working on projects, space for meetings and classes, electronics work area, and 3D printers. Downstairs is the “dirty shop,” in which one room is mostly woodworking tools with a large CNC mill and the other room contains the laser cutter and some storage. We have many shelves where members can put their projects in boxes as well as a few small storage lockers, both upstairs and downstairs.

What tools do you have in your space? (Soldering stations? Oscilloscopes? 3-D printers?)

Everything and the kitchen sink it seems like! Downstairs is a giant 80W laser cutter, a giant CNC router table (both capable of taking full sheets of plywood or other woods), a mini desktop CNC router, several different woodworking tools (bandsaw, chop saw, radial arm saw, table saw, router table, jointer, wood lathe, various power hand tools), a metal bandsaw, a micro metal lathe, a drill press, and a Zcorp powder based 3D printer. Upstairs we have several textile machines (serger, sewing machines), oscilloscopes, logic analyzers, soldering stations, three plastic FDM type 3D printers, a DIY book scanner, a large format inkjet printer, and a roomba or three.

Are there any tools your group really wants or needs?

A more reliable 3D printer would be pretty nice. Also a CNC mill capable of working metal would be really cool and would allow us to fabricate metal parts. A decent tabletop or larger metal lathe would expand our fabrication abilities. For textiles: Supplies for conductive sewing projects/classes… lilipad everything, conductive fabric, thread, battery packs, batteries. Not just for the classes themselves but also for prototyping projects.

Does your group work with embedded tech (Arduino, Raspberry Pi, embedded security, MCU-based designs, etc.)?

Yes! We have lots of Arduino and Raspberry Pi fans, but of course we have people who work with other microcontrollers as well (ARM based mostly I’d say).

Can you tell us about some of your group’s recent tech projects?

One group project we built was a laser shooting gallery — targets had light sensors and were attached to servo motors, would pop up, and then you had to shoot them with a laser pointer gun. There were sound effects and a score display. You can read more details about it here: and there are some videos here: (on the left side) One of our members has been working on using a small desktop CNC router to make custom circuit boards. It uses a neat hack to probe the level of the bed to create more accurate cuts. The results have been pretty good. There’s lots of details about this project here:

Another cool and not too complex project is 3D scanning our members and then printing out the models on our 3D printer. We use an inexpensive xbox kinect to do the scanning, along with the free version of the software Skanect, and then we load that model into our Makergear Mosaic 3D printer and spit them out. Here’s a picture of two of our members in plastic model format:

3D Scans of Ace Monster Toys' members

What’s the craziest project your group or group members have completed?

Craziest? It’s hard to say, lots of crazy stuff comes out of this place. One impressive project is our Book Scanner, made from plywood, random hardware store nuts and bolts, and a bike brake cable which triggers the shutters on two cameras to photograph two pages at once. It’s gotten a lot of press, the inventor even gave a TED Talk about it. He made his own website for it, you can find more details here:

Do you have any events or initiatives you’d like to tell us about? Where can we learn more about it?

Our current biggest initiative is moving to a bigger space. We would like to double our square footage and offer more facilities & capabilities including accessibility. For events which are going on, many of them weekly, check out the calendar on our website or on

What would you like to say to fellow hackers out there?

“Collaboration and connection has done more to further my knowledge and to produce better, more creative art and projects and innovative ideas than any other factor. Be fearless. Ask questions, try it. Don’t be afraid to cut, or solder or try even when it seems hard or complicated. Everybody starts somewhere.” ~ Crafty Rachel

Check out Ace Monster Toys’ pages on Instructables and Facebook!

You can read all about their projects on their wiki page.

Show us your hackerspace! Tell us about your group! Where does your group design, hack, create, program, debug, and innovate? Do you work in a 20′ × 20′ space in an old warehouse? Do you share a small space in a university lab? Do you meet at a local coffee shop or bar? What sort of electronics projects do you work on? Submit your hackerspace and we might feature you on our website!

Brooklyn-Based Alpha One Labs

Alpha One Labs is a very active hackerspace located in Brooklyn. They frequently host events and offer many services to their members.

Location 657 Meeker Ave #1L
Brooklyn NY, 11222
Members 25-35

Alpha One Labs

Mary Auriti is co-founder and secretary at Alpha One Labs. We ask her what she has to tell us about her space:

What’s your meeting space like?

Approximately 900 sq. ft. with 18 ft. ceilings which could accommodate a second floor. We have a wall of pegboard with tools and custom built shelves with clear containers for supplies as well as small bins for little items. There is eight heavy duty desks, a taller work table and an adjustable height desk/work table. In the front area of our space we have a little lounge area with a small sofa, book shelf, fridge, coffee maker, big flat screen TV, twitter LED scroller, old school video consoles and games, and a gallery wall featuring a local artist’s work.

What tools do you have in your space? (Soldering stations? Oscilloscopes? 3-D printers?)

We have a JCUT 6090 laser cutter, a RepRap, drill press, saws, a Dremel, and other hand tools. Also, oscilloscopes and soldering irons.

If you could add three more tools, what would they be?

Welder, Epilogue laser cutter, and a CNC 5 axis mill

Does your group work with embedded tech (Arduino, Raspberry Pi, embedded security, MCU-based designs, etc.)?

We use Arduinos and are getting into Raspberry Pi.

Can you tell us about some of your group’s recent tech projects?

We have had a wide range of projects come through our lab as well as the ongoing big project of the physical lab space itself. Some projects from the past four years are:

  • the “Twitmas Tree” (ornaments that light up every time someone tweets a holiday related word)
  • butter churning with kosher cream from bed sty
  • self-watering rooftop veggie garden
  • LED hat displaying preset or dynamic messages
  • Internet time piece
  • and a stair climbing wheelchair — to name few

What’s the craziest project your group or group members have completed?

“Shot in the Dark” — A laser pointing to the center of the toilet bowel so men have a target.

Where can the CC Community learn more about it?

We post all our events on our web site and host a few meetups from time to time as people contact us. We like to be there for any group that needs us and shares our interests in the great wide space of making, art, technology, science, education, environmentalism, hacking.

What would you like to say to fellow hackers out there?

Come on down! We are open to all and love the diversity of people who come through our lab. We are consistently working on making our lab a place to encourage innovation and give people what they need to get their projects off the ground.

Keep up with Alpha One Labs! Check out their Facebook page or Twitter feed for current events or to get involved.

Show us your hackerspace! Tell us about your group! Where does your group design, hack, create, program, debug, and innovate? Do you work in a 20′ × 20′ space in an old warehouse? Do you share a small space in a university lab? Do you meet at a local coffee shop or bar? What sort of electronics projects do you work on? Submit your hackerspace and we might feature you on our website!

Game On with the Arduino Esplora

Every time the Arduino team is about to release a new board, we expect something great in terms of better specs, more I/Os, a faster processor, more memory—or, well, just something to “fill the gap,” such as small-scale versions. With “Esplora” the Arduino team pleasantly surprises us again!

Arduino Esplora

The brand new Esplora is targeted toward gaming applications. It consists of a gamepad-shaped development board that includes an Arduino-compatible Atmel ATmega32U4, a light sensor, a temperature sensor, an accelerometer, a joystick, push buttons, a slider, an RGB LED, and a buzzer.

The Esplora is as a ready-to-use solution for designers who don’t want to deal with soldering or prototyping by means of discrete components. In fact, it comes preprogrammed with a controller script, so you only have to connect it to a PC, download the free game “Super Tux Cart,” and have fun.

An additional color LCD will be released soon in order to create a portable console. The only drawback is you can’t directly connect standard Arduino shields to it , mainly because of space limitations. Nevertheless, the board itself includes enough features to make it interesting.

The Esplora should enable you to implement a controller for almost any application you dream up. In our case, we’re sure it will bring back nice memories of the time when we were too young for soldering irons but already pros with gamepads!—Jaime González Arintero Berciano, Elektor International Media


CC269: Break Through Designer’s Block

Are you experiencing designer’s block? Having a hard time starting a new project? You aren’t alone. After more than 11 months of designing and programming (which invariably involved numerous successes and failures), many engineers are simply spent. But don’t worry. Just like every other year, new projects are just around the corner. Sooner or later you’ll regain your energy and find yourself back in action. Plus, we’re here to give you a boost. The December issue (Circuit Cellar 269) is packed with projects that are sure to inspire your next flurry of innovation.

Turn to page 16 to learn how Dan Karmann built the “EBikeMeter” Atmel ATmega328-P-based bicycle computer. He details the hardware and firmware, as well as the assembly process. The monitoring/logging system can acquire and display data such as Speed/Distance, Power, and Recent Log Files.

The Atmel ATmega328-P-based “EBikeMeter” is mounted on the bike’s handlebar.

Another  interesting project is Joe Pfeiffer’s bell ringer system (p. 26). Although the design is intended for generating sound effects in a theater, you can build a similar system for any number of other uses.

You probably don’t have to be coerced into getting excited about a home control project. Most engineers love them. Check out Scott Weber’s garage door control system (p. 34), which features a MikroElektronika RFid Reader. He built it around a Microchip Technology PIC18F2221.

The reader is connected to a breadboard that reads the data and clock signals. It’s built with two chips—the Microchip 28-pin PIC and the eight-pin DS1487 driver shown above it—to connect it to the network for testing. (Source: S. Weber, CC269)

Once considered a hobby part, Arduino is now implemented in countless innovative ways by professional engineers like Ed Nisley. Read Ed’s article before you start your next Arduino-related project (p. 44). He covers the essential, but often overlooked, topic of the Arduino’s built-in power supply.

A heatsink epoxied atop the linear regulator on this Arduino MEGA board helped reduce the operating temperature to a comfortable level. This is certainly not recommended engineering practice, but it’s an acceptable hack. (Source: E. Nisley, CC269)

Need to extract a signal in a noisy environment? Consider a lock-in amplifier. On page 50, Robert Lacoste describes synchronous detection, which is a useful way to extract a signal.

This month, Bob Japenga continues his series, “Concurrency in Embedded Systems” (p. 58). He covers “the mechanisms to create concurrently in your software through processes and threads.”

On page 64, George Novacek presents the second article in his series, “Product Reliability.” He explains the importance of failure rate data and how to use the information.

Jeff Bachiochi wraps up the issue with a article about using heat to power up electronic devices (p. 68). Fire and a Peltier device can save the day when you need to charge a cell phone!

Set aside time to carefully study the prize-winning projects from the Reneas RL78 Green Energy Challenge (p. 30). Among the noteworthy designs are an electrostatic cleaning robot and a solar energy-harvesting system.

Lastly, I want to take the opportunity to thank Steve Ciarcia for bringing the electrical engineering community 25 years of innovative projects, essential content, and industry insight. Since 1988, he’s devoted himself to the pursuit of EE innovation and publishing excellence, and we’re all better off for it. I encourage you to read Steve’s final “Priority Interrupt” editorial on page 80. I’m sure you’ll agree that there’s no better way to begin the next 25 years of innovation than by taking a moment to understand and celebrate our past. Thanks, Steve.

From the IBM PC AT to AVRs & Arduinos (CC 25th Anniversary Preview)

During the last 25 years, hundreds of the world’s most brilliant electrical engineers and embedded developers have published articles in Circuit Cellar magazine. But only a choice few had the skill, focus, creativity, and stamina to consistently publish six or more articles per year. Ed Nisley is a member of that select group. Since Issue 1, Nisley has covered topics ranging from a video hand scanner project to X10 powerline control to Arduino-based designs to crystal characterization.

In the upcoming Circuit Cellar 25th Anniversary Issue—which is slated for publication in early 2013—Nisley describes some of his most memorable projects, such as his hand Scanner design from Issue #1. He writes:

The cable in the upper-left corner went to the serial port of my Genuine IBM PC AT. The hand-wired circuit board in front came from an earlier project: an 8031-based video digitizer that captured single frames and produced, believe it or not, RS-232 serial data. It wasn’t fast, but it worked surprisingly well and, best of all, the board was relatively inexpensive. Having built the board and written the firmware, I modified it to output compressed data from hand images, then wrote a PC program to display the results.

Combining a TV camera, a prototype 8031-based video digitizer, and an IBM PC with custom firmware and software produced a digital hand scanner for Circuit Cellar Issue 1. The aluminum case came from an external 8″ floppy drive!

The robust aluminum case originally housed an external 8″ floppy drive for one of my earlier DIY “home computers” (they sure don’t make ‘em like they used to!) and I assembled the rest of the hardware in my shop. With hardware and software in hand, I hauled everything to Circuit Cellar Galactic HQ for a demo.

Some of the work Nisley details is much more modern. For instance, the photo below shows the Arduino microcontroller boards he has been using in many of his recent projects. Nisley writes:

The processors, from the Atmel AVR microcontroller family, date to the mid-1990s, with a compiler-friendly architecture producing good performance with high-level languages. Barely more than breakout boards wrapped around the microcontrollers, Arduinos provide a convenient way to mount and wire to the microcontroller chips. The hardware may be too expensive to incorporate in a product, but it’s ideal for prototypes and demonstrations.

The Arduino microcontroller project provides a convenient basis for small-scale projects like this NiMH cell tester. Simple interconnections work well with low-speed signals and lowcurrent hardware, but analog gotchas always lie in wait.

Even better, a single person can still comprehend all of a project’s hardware and software, if only because the projects tend to be human scaled. The Arduino’s open-source licensing model fits well with my column’s readily available hardware and firmware: you can reproduce everything from scratch, then extend it to suit your needs.

Circuit Cellar’s Circuit Cellar 25th Anniversary Issue will be available in early 2013. Stay tuned for more updates on the issue’s content.

Q&A: Andrew Spitz (Co-Designer of the Arduino-Based Skube)

Andrew Spitz is a Copenhagen, Denmark-based sound designer, interaction designer, programmer, and blogger studying toward a Master’s interaction design at the Copenhagen Institute of Interaction Design (CIID). Among his various innovative projects is the Arduino-based Skube music player, which is an innovative design that enables users to find and share music.

The Arduino-based Skube

Spitz worked on the design with Andrew Nip, Ruben van der Vleuten, and Malthe Borch. Check out the video to see the Skube in action.

On his blog, Spitz writes:

It is a fully working prototype through the combination of using ArduinoMax/MSP and an XBee wireless network. We access the API to populate the Skube with tracks and scrobble, and using their algorithms to find similar music when in Discover mode.

The following is an abridged  version of an interview that appears in the December 2012 issue of audioXpress magazine, a sister publication of Circuit Cellar magazine..

SHANNON BECKER: Tell us a little about your background and where you live.

Andrew Spitz: I’m half French, half South African. I grew up in France, but my parents are South African so when I was 17, I moved to South Africa. Last year, I decided to go back to school, and I’m now based in Copenhagen, Denmark where I’m earning a master’s degree at the Copenhagen Institute of Interaction Design (CID).

SHANNON: How did you become interested in sound design? Tell us about some of your initial projects.

Andrew: From the age of 16, I was a skydiving cameraman and I was obsessed with filming. So when it was time to do my undergraduate work, I decided to study film. I went to film school thinking that I would be doing cinematography, but I’m color blind and it turned out to be a bigger problem than I had hoped. At the same time, we had a lecturer in sound design named Jahn Beukes who was incredibly inspiring, and I discovered a passion for sound that has stayed with me.

Shannon: What do your interaction design studies at CIID entail? What do you plan to do with the additional education?

Andrew: CIID is focused on a user-centered approach to design, which involves finding intuitive solutions for products, software, and services using mostly technology as our medium. What this means in reality is that we spend a lot of time playing, hacking, prototyping, and basically building interactive things and experiences of some sort.

I’ve really committed to the shift from sound design to interaction design and it’s now my main focus. That said, I feel like I look at design from the lens of a sound designer as this is my background and what has formed me. Many designers around me are very visual, and I feel like my background gives me not only a different approach to the work but also enables me to see opportunities using sound as the catalyst for interactive experiences. Lots of my recent projects have been set in the intersection among technology, sound, and people.

SHANNON: You have worked as a sound effects recordist and editor, location recordist and sound designer for commercials, feature films, and documentaries. Tell us about some of these experiences?

ANDREW: I love all aspects of sound for different reasons. Because I do a lot of things and don’t focus on one, I end up having more of a general set of skills than going deep with one—this fits my personality very well. By doing different jobs within sound, I was able to have lots of different experiences, which I loved! nLocation recording enabled me to see really interesting things—from blowing up armored vehicles with rocket-propelled grenades (RPGs) to interviewing famous artists and presidents. And, documentaries enabled me to travel to amazing places such as Rwanda, Liberia, Mexico, and Nigeria. As a sound effects recordist on Jock of the Bushvelt, a 3-D animation, I recorded animals such as lions, baboons, and leopards in the South African bush. With Bakgat 2, I spent my time recording and editing rugby sounds to create a sound effects library. This time in my life has been a huge highlight, but I couldn’t see myself doing this forever. I love technology and design, which is why I made the move...

SHANNON: Where did the idea for Skube originate?

Andrew: Skube came out of the Tangible User Interface (TUI) class at CIID where we were tasked to rethink audio in the home context. So understanding how and where people share music was the jumping-off point for creating Skube.

We realized that as we move more toward a digital and online music listening experience, current portable music players are not adapted for this environment. Sharing mSkube Videousic in communal spaces is neither convenient nor easy, especially when we all have such different taste in music.

The result of our exploration was Skube. It is a music player that enables you to discover and share music and facilitates the decision process of picking tracks when in a communal setting.

audioXpress is an Elektor International Media publication.

MCU-Based Prosthetic Arm with Kinect

James Kim—a biomedical student at Ryerson University in Toronto, Canada—recently submitted an update on the status of an interesting prosthetic arm design project. The design features a Freescale 9S12 microcontroller and a Microsoft Kinect, which tracks arm movements that are then reproduced on the prosthetic arm.

He also submitted a block diagram.

Overview of the prosthetic arm system (Source: J. Kim)

Kim explains:

The 9S12 microcontroller board we use is Arduino form-factor compatible and was coded in C using Codewarrior.  The Kinect was coded in C# using Visual Studio using the latest version of Microsoft Kinect SDK 1.5.  In the article, I plan to discuss how the microcontroller was set up to do deterministic control of the motors (including the timer setup and the PID code used), how the control was implemented to compensate for gravitational effects on the arm, and how we interfaced the microcontroller to the PC.  This last part will involve a discussion of data logging as well as interfacing with the Kinect.

The Kinect tracks a user’s movement and the prosthetic arm replicates it. (Source: J. Kim, YouTube)

The system includes:

Circuit Cellar intends to publish an article about the project in an upcoming issue.

Q&A: Guido Ottaviani (Roboticist, Author)

Guido Ottaviani designs and creates innovative microcontroller-based robot systems in the city from which remarkable innovations in science and art have originated for centuries.

Guido Ottaviani

By day, the Rome-based designer is a technical manager for a large Italian editorial group. In his spare time he designs robots and interacts with various other “electronics addicts.” In an a candid interview published in Circuit Cellar 265 (August 2012), Guido described his fascination with robotics, his preferred microcontrollers, and some of his favorite design projects. Below is an abridged version of the interview.

NAN PRICE: What was the first MCU you worked with? Where were you at the time? Tell us about the project and what you learned.

GUIDO OTTAVIANI: The very first one was not technically an MCU, that was too early. It was in the mid 1980s. I worked on an 8085 CPU-based board with a lot of peripherals, clocked at 470 kHz (less than half a megahertz!) used for a radio set control panel. I was an analog circuits designer in a big electronics company, and I had started studying digital electronics on my own on a Bugbook series of self-instruction books, which were very expensive at that time. When the company needed an assembly programmer to work on this board, I said, “Don’t worry, I know the 8085 CPU very well.” Of course this was not true, but they never complained, because that job was done well and within the scheduled time.

I learned a lot about how to optimize CPU cycles on a slow processor. The program had very little time to switch off the receiver to avoid destroying it before the powerful transmitter started.

Flow charts on paper, a Motorola developing system with the program saved on an 8” floppy disk, a very primitive character-based editor, the program burned on an external EPROM and erased with a UV lamp. That was the environment! When, 20 years later, I started again with embedded programming for my hobby, using Microchip Technology’s MPLAB IDE (maybe still version 6.xx) and a Microchip Technology PIC16F84, it looked like paradise to me, even if I had to relearn almost everything.

But, what I’ve learned about code optimization—both for speed and size—is still useful even when I program the many resources on the dsPIC33F series…

NAN: You worked in the field of analog and digital development for several years. Tell us a bit about your background and experiences.

GUIDO: Let me talk about my first day of work, exactly 31 years ago.

Being a radio amateur and electronics fan, I went often to the surplus stores to find some useful components and devices, or just to touch the wonderful receivers or instruments: Bird wattmeters, Collins or Racal receivers, BC 312, BC 603 or BC 1000 military receivers and everything else on the shelves.

The first day of work in the laboratory they told to me, “Start learning that instrument.” It was a Hewlett-Packard spectrum analyzer (maybe an HP85-something) that cost more than 10 times my annual gross salary at that time. I still remember the excitement of being able to touch it, for that day and the following days. Working in a company full of these kinds of instruments (the building even had a repair and calibration laboratory with HP employees), with more than a thousand engineers who knew everything from DC to microwaves to learn from, was like living in Eden. The salary was a secondary issue (at that time).

I worked on audio and RF circuits in the HF to UHF bands: active antennas, radiogoniometers, first tests on frequency hopping and spread spectrum, and a first sample of a Motorola 68000-based GPS as big as a microwave oven.

Each instrument had an HPIB (or GPIB or IEEE488) interface to the computer. So I started approaching this new (for me) world of programming an HP9845 computer (with a cost equivalent to 5 years of my salary then) to build up automatic test sets for the circuits I developed. I was very satisfied when I was able to obtain a 10-Hz frequency hopping by a Takeda-Riken frequency synthesizer. It was not easy with such a slow computer, BASIC language, and a bus with long latencies. I had to buffer each string of commands in an array and use some special pre-caching features of the HPIB interface I found in the manual.

Every circuit, even if it was analog, was interfaced with digital ports. The boards were full of SN74xx (or SN54xx) ICs, just to make some simple functions as switching, multiplexing, or similar. Here again, my lack of knowledge was filled with the “long history experience” on Bugbook series.

Well, audio, RF, programming, communications, interfacing, digital circuits. What was I still missing to have a good background for the next-coming hobby of robotics? Ah! Embedded programming. But I’ve already mentioned this experience.

After all these design jobs, because my knowledge started spreading on many different projects, it was natural to start working as a system engineer, taking care of all the aspects of a complex system, including project management.

NAN: You have a long-time interest in robotics and autonomous robot design. When did you first become interested in robots and why?

GUIDO: I’ve loved the very simple robots in the toy store windows since I was young, the same I have on my website (Pino and Nino). But they were too simple. Just making something a little bit more sophisticated required too much electronics at that time.

After a big gap in my electronics activity, I discovered a newly published robotic magazine, with an electronic parts supplement. This enabled me to build a programmable robot based on a Microchip PIC16F84. A new adventure started. I felt much younger. Suddenly, all the electronics-specialized neurons inside my brain, after being asleep for many years, woke up and started running again. Thanks to the Internet (not yet available when I left professional electronics design), I discovered a lot of new things: MCUs, free IDEs running even on a simple computer, free compilers, very cheap programming devices, and lots of documentation freely available. I threw away the last Texas Instruments databook I still had on my bookshelf and started studying again. There were a lot of new things to know, but, with a good background, it was a pleasant (if frantic) study. I’ve also bought some books, but they became old before I finished reading them.

Within a few months, jumping among all the hardware and software versions Microchip released at an astonishing rate, I found Johann Borenstein et al’s book Where Am I?: Systems and Methods for Mobile Robot Positioning (University of Michigan, 1996). This report and Borenstein’s website taught me a lot about autonomous navigation techniques. David P. Anderson’s “My Robots” webpage ( inspired all my robots, completed or forthcoming.

I’ve never wanted to make a remote-controlled car, so my robots must navigate autonomously in an unknown environment, reacting to the external stimuli. …

NAN: Robotics is a focal theme in many of the articles you have contributed to Circuit Cellar. One of your article series, “Robot Navigation and Control” (224–225, 2009), was about a navigation control subsystem you built for an autonomous differential steering explorer robot. The first part focused on the robotic platform that drives motors and controls an H-bridge. You then described the software development phase of the project. Is the project still in use? Have you made any updates to it?

The “dsNavCon” system features a Microchip Technology dsPIC30F4012 motor controller and a general-purpose dsPIC30F3013. (Source: G. Ottaviani, CC224)

GUIDO: After I wrote that article series, that project evolved until the beginning of this year. There is a new switched power supply, a new audio sensor, the latest version of dsNav dsPIC33-based board became commercially available online, some mechanical changing, improvements on telemetry console, a lot of modifications in the firmware, and the UMBmark calibration performed successfully.

The goal is reached. That robot was a lab to experiment sensors, solutions, and technologies. Now I’m ready for a further step: outdoors.

NAN: You wrote another robotics-related article in 2010 titled, “A Sensor System for Robotics Applications” (Circuit Cellar 236). Here you describe adding senses—sight, hearing, and touch—to a robotics design. Tell us about the design, which is built around an Arduino Diecimila board. How does the board factor into the design?

An Arduino-based robot platform (Source: G. Ottavini, CC236)

GUIDO: That was the first time I used an Arduino. I’ve always used PICs, and I wanted to test this well-known board. In that case, I needed to interface many I2C, analog sensors, and an I2C I/O expander. I didn’t want to waste time configuring peripherals. All the sensors had 5-V I/O. The computing time constraints were not so strict. Arduino fits perfectly into all of these prerequisites. The learning curve was very fast. There was already a library of every device I’ve used. There was no need for a voltage level translation between 3.3 and 5 V. Everything was easy, fast, and cheap. Why not use it for these kinds of projects?

NAN: You designed an audio sensor for a Rino robotic platform (“Sound Tone Detection with a PSoC Part 1 and Part 2,” Circuit Cellar 256–257, 2011). Why did you design the system? Did you design it for use at work or home? Give us some examples of how you’ve used the sensor.

GUIDO: I already had a sound board based on classic op-amp ICs. I discovered the PSoC devices in a robotic meeting. At that moment, there was a special offer for the PSoC1 programmer and, incidentally, it was close to my birthday. What a perfect gift from my relatives!

This was another excuse to study a completely different programmable device and add something new to my background. The learning curve was not as easy as the Arduino one. It is really different because… it does a very different job. The new PSoC-based audio board was smaller, simpler, and with many more features than the previous one. The original project was designed to detect a fixed 4-kHz tone, but now it is easy to change the central frequency, the band, and the behavior of the board. This confirms once more, if needed, that nowadays, this kind of professional design is also available to hobbyists. …

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?

GUIDO: As often happens, the “big thing” is one of the smallest ones. Many manufacturers are working on micro-nano-pico watt devices. I’ve done a little but not very extreme experimenting with my Pendulum project. Using the sleeping features of a simple PIC10F22P with some care, I’ve maintained the pendulum’s oscillation bob for a year with a couple of AAA batteries and it is still oscillating behind me right now.

Because of this kind of MCU, we can start seriously thinking about energy harvesting. We can get energy from light, heat, any kind of RF, movement or whatever, to have a self-powered, autonomous device. Thanks to smartphones, PDAs, tablets, and other portable devices, the MEMS sensors have become smaller and less expensive.

In my opinion, all this technology—together with supercapacitors, solid-state batteries or similar—will spread many small devices everywhere to monitor everything.

The entire interview is published in Circuit Cellar 265 (August 2012).

Issue 265: Embedded Systems Abound

I recently read on the transcript of an interview (May 9, 2002) with arachnologist Norman Platnick who stated: “You’re probably within seven or eight feet of spider no matter where you are. The only place on earth that has no spiders at all—as far as we know—is Antarctica.” It didn’t take long for me to start thinking about embedded systems and my proximity to them. Is the average person always within several feet of embedded systems? Probably not. But what about 50% or 60% of the time? E-mail me your thoughts.

Circuit Cellar 265, August 2012 - Embedded Development

Embedded systems are becoming ubiquitous. They’re in vehicles, mobile electronics, toys, industrial applications, home appliances, and more. If you’re indoors, the temperature is likely monitored and controlled by an embedded system. When you’re engaged in outdoor activities (e.g., hiking, golfing, biking, or boating), you probably have a few MCU-controlled devices nearby, such as cell phones, rangefinders, pedometers, and navigation systems. This month we present articles about how embedded systems work, and our authors also provide valuable insight about topics ranging from concurrency to project development.

Freescale’s Mark Pedley kicks off the issue with a revealing article about a tilt-compensating electronic compass (p. 16). Now you can add an e-compass to your next MCU-based project.

E-compass technology (Source: M. Pedley, CC265)

Turn to page 24 for an in-depth interview with Italy-based engineer Guido Ottaviani. His fascination with electronics engineering, and robotics in particular, will inspire you.

Have you ever come across a product that you know you could have designed better? Scott Weber had that experience and then acted on his impulse to build a more effective system. He created an MCU-based light controller (p. 32).

The MCU-based light controller is on the right (Source: S. Weber, CC265)

If you want to ensure a microcontroller works efficiently within one of your systems, you should get to know it inside and out. Shlomo Engelberg examines the internal structure of an I/O pin with a pull-up resistor (p. 40).

Bob Japenga continues his series “Concurrency in Embedded Systems” on page 44. He covers atomicity and time of check to time of use (TOCTTOU).

On page 48 George Novacek presents the second part of his series on project development. He covers project milestones and design reviews.

Ed Nisley’s June 2012 article introduced the topic of MOSFET channel resistance. On page 52 he covers his Arduino-based MOSFET tester circuitry and provides test results.

The MOSFET tester PCB hides the Arduino that runs the control program and communicates through the USB cable on the left edge. (Source: E. Nisley, CC265)

If you read Robert Lacoste’s June 2012 article, you now understand the basics of frequency mixers. This month he presents high-level design methods and tools (p. 58).

Jeff Bachiochi wraps up the issue with an examination of a popular topic—energy harvesting (p. 68). He covers PV cell technology, maximum power point tracking (MPPT), and charge management control.

A great way to investigate MPPT for your design is to use an STMicroelectronics evaluation board, such as this STEVAL-ISV006V2 shown in the top of the photo. The smaller cell in the center is rated at 165 mW (0.55-V output at 0.3 A) measuring 1.5” × 0.75”. At the bottom is a Parallax commercial-quality solar cell that is rated at 2.65 W (0.534-V output at 5.34 A) measuring 125 mm. (Source: J. Bachiochi, CC265)

Circuit Cellar 265 is currently on newsstands.

Elektor Weekly Wrap-Up: Receiver Project, Arduino-Based Design, & More

It’s officially summertime when Elektor’s special summer issue hits the newsstands. This year the team put together an attention-grabbing issue—complete with a redesigned layout—that’s packed with articles on projects such as a wearable distance-measuring device for swimmers, a music-making application with an Arduino, an “e-smog” detector, an innovative two-transistor regenerative receiver project, and more.

The two-transistor regenerative receiver

Editor-in-Chief Wisse Hettinga presents the issue in the following short video.

The 2012 summer issue is now available.

Elektor's 2012 summer issue

In other news, the Elektor team announced a new book on BASCOM-AVR is in the pipeline.

AVR microcontrollers are popular, easy to use and extremely versatile. Elektor magazine already produced a wealth of special applications and circuit boards based on ATmega and ATtiny controllers. These were mostly finished projects. In this book however the programming of these controllers is the foremost concern. BASCOM is an ideal tool for this. After a minimal preparation phase, you can start right away putting your own ideas into practice.

BASCOM and AVR microcontrollers — it’s an unbeatable team! Whatever you want to develop, in most cases the ATmega has everything you need on board. Ports, timers, A/D converters, PWM outputs and serial interfaces, RAM, flash ROM and EEPROM: everything is in plentiful supply, and with BASCOM their use is child’s play. More challenging peripherals like LCDs, RC5 and I2C can be used as well with just a handful of instructions. A wide hardware platform is available, too. Whether you’re using Atmel’s STK500 kit, the Elektor ATM18 or your own board, you can instantly turn the examples from this book into practice. For less exacting tasks controllers from the ATtiny are series used. That way, you can realize your own projects quickly and with little expense.

The companion CD-ROM with this book provides sample programs and software including BCAVRDMO, AVR STUDIO, LCDTOOLS, and TERMINAL.EXE.

Elektor members can preorder the book now. is an Elektor International Media publication.


A Workspace Where Meccano Meets Arduino

Peeking into someone’s workspace gives you a glimpse of their interests, personality, and aspirations. Thus, in the same way no two personalities are exactly same, no two workspaces are identical. Some workspaces are retreat-like locations where designers spend their precious “alone time”; other spaces are 24/7 where innovators work, play, eat, and even sleep. Some spaces are intended for leisurely designing, learning, programming, and tinkering. Other spaces are high-pressure work zones where electronics innovators endeavor around the clock to create the systems and programs that pay their bills. And so it’s due to the personal nature of each workspace that we’re grateful to the generous innovators who’ve pulled back the curtains to give us a look.

Today let’s check out a space that’s intended more for innovation and learning than building the next money-making embedded system.

Ralph Laughton’s multifunctional London-based workspace was designed for model-making and Meccano-building. It wasn’t intended to be an electrical engineering workspace.

But Circuit Cellar and Elektor members shouldn’t overlook a space simply because it isn’t full of MCUs, soldering irons, PCBs, and EE test equipment. You can learn a lot by studying someone’s work area: innovative storage systems, novel workbench designs, handy power supply solutions, equipment customization, and more.

Laughton's bench in London

Laughton wrote the following with his submission:

Please find attached a photograph of my modest workspace here in my workshop in London, England. My space has to be shared with other activities such as model making as in this picture. Component storage and larger equipment is stored to one side of the bench, keeping the main area clear. The shelves across the window are mounted on adjustable brackets. Not only does this give flexibility, but it enables easy access to the window and blind for cleaning and maintenance.

On his blog he writes:

My workshop has to accommodate woodworking, model making, photography as well as anything else that needs fixing, modifying or investigating.

When comes to investigating, Laughton has begun learning about Arduino. In late April he posted the following about his early experiences with it:

I am now at the stage where I can make it do what it is supposed to do and I have even written and modified my own lump of code. This may not seem like much to some of you reading this but for me this is a big leap into the world of digital electronics and microprocessors—something I didn’t think I would ever entertain. Mind you, what do I know? I used to think digital photography would never catch on.

So, with Arduino and the recent purchase of a scope (see his May 2 post), Laughton is positioning himself to take on more electronics projects in his multifuctional workspace

We can’t wait to see what sorts of Arduino-controlled Meccano projects he creates.

Do you want to share photos of your personal electronics workspace, hackspace, or “circuit cellar”? Do you have an article or tutorial you’d Circuit Cellar to consider for publication? Click here to submit your proposal or write-up and photos. Write “Submission” or “Proposal” in the subject line of your email.