About Circuit Cellar Staff

Circuit Cellar's editorial team comprises professional engineers, technical editors, and digital media specialists. You can reach the Editorial Department at editorial@circuitcellar.com, @circuitcellar, and facebook.com/circuitcellar

How to Protect Electronic Systems

Engineers must protect their electronic systems. Thus, we frequently get requests for tips, tricks, and insight on the topic. For instance, a UK-based community member recently requested some insight into electronics protection and bullet proofing. We provided him with the content below. And now we want to pass it on to you as well.

Robert Lacoste shows the 3-D printer (a) he used to build an acrylonitrile butadiene styrene (ABS) shield (b).

Robert Lacoste shows the 3-D printer (a) he used to build an acrylonitrile butadiene styrene (ABS) shield (b).

Self-Reconfiguring Robotic Systems & M-Blocks

Self-reconfiguring robots are no longer science fiction. Researchers at MIT are rapidly innovating shape-shifting robotic systems. In the August 2014 issue of Circuit Cellar, MIT researcher Kyle Gilpin presents M-Blocks, which are 50-mm cubic modules capable of controlled self-reconfiguration.

The creation of autonomous machines capable of shape-shifting has been a long-running dream of scientists and engineers. Our enthusiasm for these self-reconfiguring robots is fueled by fantastic science fiction blockbusters, but it stems from the potential that self-reconfiguring robots have to revolutionize our interactions with the world around us.

Source: Kyle Gilpin

Source: Kyle Gilpin

Imagine the convenience of a universal toolkit that can produce even the most specialized tool on demand in a matter of minutes. Alternatively, consider a piece of furniture, or an entire room, that could change its configuration to suit the personal preferences of its occupant. Assembly lines could automatically adapt to new products, and construction scaffolding could build itself while workers sleep. At MIT’s Distributed Robotics Lab, we are working to make these dreams into reality through the development of the M-Blocks.

The M-Blocks are a set of 50-mm cubic modules capable of controlled self-reconfiguration. Each M-Block is an autonomous robot that can not only move independently, but can also magnetically bond with other M-Blocks to form larger reconfigurable systems. When part of a group, each module can climb over and around its neighbors. Our goal is that a set of M-Blocks, dispersed randomly across the ground, could locate one another and then independently move to coalesce into a macro-scale object, like a chair. The modules could then reconfigure themselves into a sphere and collectively roll to a new location. If, in the process, the collective encounters an obstacle (e.g., a set of stairs to be ascended), the sphere could morph into an amorphous collection in which the modules climb over one another to surmount the obstacle.  Once they have reached their final destination, the modules could reassemble into a different object, like a desk.

The M-Blocks move and reconfigure by pivoting about their edges using an inertial actuator. The energy for this actuation comes from a 20,000-RPM flywheel contained within each module. Once the motor speed has stabilized, a servomotor-driven, self-tightening band brake decelerates the flywheel to a complete stop in 15 ms. All of the momentum that had been accumulated in the flywheel is transferred to the frame of the M-Block. Consequently, the module rolls forward from one face to the next, or if the flywheel velocity is high enough, it rapidly shoots across the ground or even jumps several body lengths through the air. (Refer to www.youtube.com/watch?v=mOqjFa4RskA  to watch the cubes move.)

While the M-Blocks are capable of independent movement, their true potential is only realized when many modules operate as a group. Permanent magnets on the outside of each M-Block serve as un-gendered connectors. In particular, each of the 12 edges holds two cylindrical magnets that are captive, but free to rotate, in a semi-enclosing cage. These magnets are polarized through their radii, not through their long axes, so as they rotate, they can present either magnetic pole. The benefit of this arrangement is that as two modules are brought together, the magnets will automatically rotate to attract. Furthermore, as one and then two additional M-Blocks are added to form a 2 × 2 grid, the magnets will always rotate to realign and accommodate the additional modules.

The same cylindrical magnets that bond neighboring M-Blocks together form excellent pivot axes, about which the modules may roll over and around one another. We have shown that the modules can climb vertically over other modules, move horizontally while cantilevered from one side, traverse while suspended from above, and even jump over gaps. The permanent magnet connectors are completely passive, requiring no control and no planning. Because all of the active components of an M-Block are housed internally, the modules could be hermetically sealed, allowing them to operate in extreme environment where other robotic systems may fail.

While we have made significant progress, many exciting challenges remain. In the current generation of modules, there is only a single flywheel, and it is fixed to the module’s frame, so the modules can only move in one direction along a straight line. We are close to publishing a new design that enables the M-Blocks to move in three dimensions, makes the system more robust, and ensures that the modules’ movements are highly repeatable. We also hope to build new varieties of modules that contain cameras, grippers, and other specialized, task-specific tools. Finally, we are developing algorithms that will allow for the coordinated control of large ensembles of hundreds or thousands of modules. With this continued development, we are optimistic that the M-Blocks will be able to solve a variety of practical challenges that are, as of yet, largely untouched by robotics.

Kyle Gilpin

Kyle Gilpin


Kyle Gilpin, PhD, is a Postdoctoral Associate in the Distributed Robotics Lab at the Massachusetts Institute of Technology (MIT) where he is collaborating with Professor Daniela Rus and John Romanishin to develop the M-Blocks. Kyle works to improve communication and control in large distributed robotic systems. Before earning his PhD, Kyle spent two years working as a senior electrical engineer at a biomedical device start-up. In addition to working for MIT, he owns a contract design and consulting business, Crosscut Prototypes. His past projects include developing cellular and Wi-Fi devices, real-time image processing systems, reconfigurable sensor nodes, robots with compliant SMA actuators, integrated production test systems, and ultra-low-power sensors.

Circuit Cellar 289 (August 2014) is now available.

Data Communication Between “Smart” Pendants

As head of the Computer Science and Software  Engineering department at Penn State Erie, The Behrend College, Chris Coulston is busy.

But not too busy to surf the ‘Net for design inspiration.

And one of his latest projects may earn him the title of “social jewelry designer,” along with college professor and department chair.

In the June issue of Circuit Cellar, Coulston writes about his design and construction of an RGB LED pendant that “cycles through a color sequence, detects when another pendant is brought into its proximity, and communicates color sequence information to the other pendant through its LED.” The heart of the design is a Seoul Semiconductor SFT722 RGB LED.

Coulston was online a few years ago when he ran across the first half of his project inspiration—a Mitsubishi Electric Research Laboratories technical report titled “Very Low-Cost Sensing and Communication Using Bi-directional LEDs.” The report, Coulston says, “describes how an ordinary LED with no additional circuitry can act as a full-duplex communication channel.”

Pendant’s two boards

His remaining inspiration came from an article he recalled appearing in Circuit Cellar a decade ago.

The Mitsubishi labs technical report “got me thinking about Jeff Bachiochi’s article ‘Designing with RGB LEDs’ (Circuit Cellar 159, 2003), in which the challenges associated with designing a piece of LED jewelry are described,” Coulston says. “The fusion of these two ideas was the inspiration for my social jewelry design.”

Coulston’s design includes a pair of circuit boards, the upper containing the LED and analog circuitry and the lower containing the microcontroller.

“The prototype pendant is mainly controlled through a USB-to-USART bridge,” Couston says. “Its power is supplied by the same connection.”

He invites anyone who is  “curious how an LED can be used as a transceiver and how it’s used to build a piece of social jewelry” to read his article. You’ll find it in next month’s issue of Circuit Cellar.

New PIC32 Bluetooth Starter Kit

Microchip Technology recently announced the new PIC32 Bluetooth Starter Kit, which is intended for low-cost applications such as a Bluetooth thermostat, wireless diagnostic tools, and Bluetooth GPS receivers. According to Microchip, the kit includes “a PIC32 microcontroller, HCI-based Bluetooth radio, Cree high-output multi-color LED, three standard single-color LEDs, an analog three-axis accelerometer, analog temperature sensor, and five push buttons for user-defined inputs.”

PIC32 Bluetooth Starter Kit (Source: Microchip Technology)

PIC32 Bluetooth Starter Kit (Source: Microchip Technology)

PICkit On Board (PKOB) eliminates the need for an external debugger/programmer, USB connectivity, and GPIOs for rapid development of Bluetooth Serial Port Profile (SPP), USB and general-purpose applications.  The starter kit also features a plug-in interface for an audio CODEC daughter card. The kit’s PIC32MX270F256D microcontroller operates at 83 DMIPS with 256-KB flash memory and 64-KB RAM.

The PIC32 Bluetooth Starter Kit is supported by Microchip’s free MPLAB X IDE and MPLAB Harmony Integrated Software Framework.  Additionally, the free Quick Start Package is available with an Android application development environment. It also includes a free SDK with the application source code and binary for Microchip’s Bluetooth SPP library.  Both are optimized for the on-board PIC32 MCU and are available for free at www.microchip.com/get/1AVL.


The PIC32 Bluetooth Starter Kit costs $79.99.

Windows-Compatible Dev Board

Intel, Microsoft, and Circuit Co. have teamed up to produce a development board designed for the production of software and drivers used on mobile devices such as phones, tablets and similar System on a Chip (SoC) platforms running Windows and Android operating systems with Intel processors.

Source: SharksCove.org

Source: SharksCove.org

The 6″ × 4″ Sharks Cove board and features a number of interfaces including GPIO, I2C, I2S, UART, SDIO, mini USB, USB, and MIPI for display and camera.

Its main features include:

  • Intel  ATOM Processor Z3735G , 2M Cache, 4 Core, 1.33 GHz up
    to 1.88 GHz
  • Intel HD Graphics
  • 1 GB 1×32 DDR3L-RS-1333, 16-GB EMMC storage, micro SD Card
  • HDMI full size connector, MIPI display connector
  • Twelve (5 × 2) Shrouded pin header connectors, 1 (2 × 10) sensor header, 2 × 60 pin MIPI connector for display, camera and 5 (2 × 2) headers for power
  • One USB 2.0 type A connector
  • One micro USB type A/B for debug
  • Audio Codec Realtek ALC5640, speaker output header and onboard digital mic
  • Ethernet or WiFi via USB
  • Intel UEFI BIOS
  • Power, volume up, volume down, home screen and rotation lock
  • One micro USB type A/B for Power
  • SPI debug programming header

You can preorder the board for $299. It includes a Windows 8.1 image together with all the necessary utilities for it to run on Sharks Cove.