About Nan Price

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

“No Opto” Synchronous Forward Controller

LinearThe LT3752/LT3752-1 is a high-input voltage-capable synchronous forward controller with an active clamp transformer reset. A controlled VOUT start-up and shut-down is maintained with an integrated housekeeping controller to bias the primary and secondary ICs. The internal bias generation also reduces the main power transformer’s complexity and size by avoiding the need for extra windings to create bias supplies.

The LT3752 operates over a 6.5-to-100-V input voltage range. The LT3752-1 is well suited for hybrid vehicle (HV) and hybrid electric vehicle (HEV) applications. For up to 400-V inputs and greater, it enables RC start-up from the input voltage with the maximum voltage limited only by the choice of external components.

A ±5% output voltage regulation can be attained without using an optocoupler. An optocoupler can be used to obtain ±1.5% output voltage regulation. The LT3752/-1 uses a pulse transformer to send a control signal to a secondary-side MOSFET driver for the synchronous rectification timing. It can also be used in self-driven applications the power transformer pulses control the secondary-side MOSFETs. With the LT3752/-1, secondary-side ICs no longer require start-up circuitry to operate when the output voltage is 0 V, which enables a controlled VOUT start-up.

The LT3752/-1 has a programmable 100-to-500-kHz operating switching frequency. It can be synchronized to an external clock, so a range of output inductor values and transformer sizes can be used.

The LT3752/-1 is available in a TSSOP-38 package with several pins removed for high-voltage spacing. The LT3752/-1 E- and I-grade versions function from a –40°C-to-125°C junction temperature. The LT3752/-1 H-grade functions from a –40°C-to-150°C operating junction temperature. The LT3752/-1 MP-grade functions from –55°C-to-150°C operating junction temperature.

The LT3752/LT3752-1 costs $3.39 in 1,000-piece quantities.

Linear Technology Corp.
www.linear.com

COM Express Module With 2nd-Generation Intel Core

DynatemThe CPU-162-14 is a high-performance COM Express module based on the Intel Core i7 Processor. The COM is designed to work in harsh environments. It includes features to provide extra resilience to vibrations, making it well suited for transportation applications.

The CPU-162-14 includes extended temperature versions for –40°-to-85° operation; direct-mounted RAM and a CPU to withstand stress and vibration; up to 8 GB double data rate type three synchronous dynamic RAM (DDR3 SDRAM); and three video ports including video graphics array (VGA), Intel’s Serial Digital Video Out (SDVO), and low-voltage differential signaling (LVDS).

Contact Dynatem for pricing.

Dynatem, Inc.
www.dynatem.com

Arbitrary Waveform Generator

The AWG18 is an arbitrary waveform generator designed for use with Applicos’s ATX-series of test systems. The waveform generator features an 18-bit resolution at a 300 megasamples-per-second (MSPS) data rate and oversampling at a 600-MSPS or 1.2 gigasamples-per-second (GSPS) rate.

Testing analog systems with high-speed 14- and 16-bit data converters requires extremely clean signals. The traditional approach of filtering away the harmonics is insufficient when dealing with a high signal-to-noise ratio (SNR), maintaining a high spurious-free dynamic range (SFDR), or when a low “close-in carrier noise” is preferred. In these cases, the extra precision from an 18-bit signal value can create a reliable test-stand operation and reduce random failures.

ApplicosMany applications need to use signals other than sine waves to make additional time domain measurements. To accommodate this, the AWG18 has two signal paths: one path starts at DC for time domain and general-purpose measurements that require high-level accuracy. The other path runs from 10 to 100 MHz and is optimized for dynamic signal generation in this frequency range. The typical total harmonic distortion (THD) for frequencies up to 50 MHz is above 100 dBc.

Contact Applicos for pricing.

Applicos BV
www.applicos.com

Real-Time Processing for PCIe Digitizers

Agilent U5303A PCIe 12bit High-Speed DigitizerThe U5303A digitizer and the U5340A FPGA development kit are recent enhancements to Agilent Technologies’s PCI Express (PCIe) high-speed digitizers. The U5303A and the U5340A FPGA add next-generation real-time peak detection functionalities to the PCIe devices.

The U5303A is a 12-bit PCIe digitizer with programmable on-board processing. It offers high performance in a small footprint, making it an ideal platform for many commercial, industrial, and aerospace and defense embedded systems. A data processing unit (DPU) based on the Xilinx Virtex-6 FPGA is at the heart of the U5303A. The DPU controls the module functionality, data flow, and real-time signal processing. This feature enables data reduction and storage to be carried out at the digitizer level, minimizing transfer volumes and accelerating analysis.

The U5340A FPGA development kit is designed to help companies and researchers protect their IP signal-processing algorithms. The FPGA kit enables integration of an advanced real-time signal processing algorithm within Agilent Technologies’s high-speed digitizers. The U5340A features high-speed medical imaging, analytical time-of-flight, lidar ranging, non-destructive testing, and a direct interface to digitizer hardware elements (e.g., the ADC, clock manager, and memory blocks). The FPGA kit includes a library of building blocks, from basic gates to dual-port RAM; a set of IP cores; and ready-to-use scripts that handle all aspects of the build flow.

Contact Agilent Technologies for pricing.

Agilent Technologies, Inc.
www.agilent.com

A Workspace for “Engineering Magic”

Brandsma_workspace2

Photo 1—Brandsma describes his workspace as his “little corner where the engineering magic happens.”

Sjoerd Brandsma, an R&D manager at CycloMedia, enjoys designing with cameras, GPS receivers, and transceivers. His creates his projects in a small workspace in Kerkwijk, The Netherlands (see Photo 1). He also designs in his garage, where he uses a mill and a lathe for some small and medium metal work (see Photo 2).

Brandsma_lathe_mill

Photo 2—Brandsma uses this Weiler lathe for metal work.

The Weiler lathe has served me and the previous owners for many years, but is still healthy and precise. The black and red mill does an acceptable job and is still on my list to be converted to a computer numerical control (CNC) machine.

Brandsma described some of his projects.

Brandsma_cool_projects

Photo 3—Some of Brandsma’s projects include an mbed-based camera project (left), a camera with an 8-bit parallel databus interface (center), and an MP3 player that uses a decoder chip that is connected to an mbed module (right).

I built a COMedia C328 UART camera with a 100° lens placed on a 360° servomotor (see Photo 3, left).  Both are connected to an mbed module. When the system starts, the camera takes a full-circle picture every 90°. The four images are stored on an SD card and can be stitched into a panoramic image. I built this project for the NXP mbed design challenge 2010 but never finished the project because the initial idea involved doing some stitching on the mbed module itself. This seemed to be a bit too complicated due to memory limitations.

I built this project built around a 16-MB framebuffer for the Aptina MT9D131 camera (see Photo 3, center). This camera has an 8-bit parallel databus interface that operates on 6 to 80 MHz. This is way too fast for most microcontrollers (e.g., Arduino, Atmel AVR, Microchip Technology PIC, etc.). With this framebuffer, it’s possible to capture still images and store/process the image data at a later point.

This project involves an MP3 player that uses a VLSI VS1053 decoder chip that is connected to an mbed module (see Photo 3, right). The great thing about the mbed platform is that there’s plenty of library code available. This is also the case for the VS1053. With that, it’s a piece of cake to build your own MP3 player. The green button is a Skip button. But beware! If you press that button it will play a song you don’t like and you cannot skip that song.

He continued by describing his test equipment.

Brandma_test_equipment

Photo 4—Brandsma’s test equipment collection includes a Tektronix TDS220 oscilloscope (top), a Total Phase Beagle protocol analyzer (second from top), a Seeed Technology Open Workbench Logic Sniffer (second from bottom), and a Cypress Semiconductor CY7C68013A USB microcontroller (bottom).

Most of the time, I’ll use my good old Tektronix TDS220 oscilloscope. It still works fine for the basic stuff I’m doing (see Photo 4, top). The Total Phase Beagle I2C/SPI protocol analyzer Beagle/SPI is a great tool to monitor and analyze I2C/SPI traffic (see Photo 4, second from top).

The red PCB is a Seeed Technology 16-channel Open Workbench Logic Sniffer (see Photo 4, second from bottom). This is actually a really cool low-budget open-source USB logic analyzer that’s quite handy once in a while when I need to analyze some data bus issues.

The board on the bottom is a Cypress CY7C68013A USB microcontroller high-speed USB peripheral controller that can be used as an eight-channel logic analyzer or as any other high-speed data-capture device (see Photo 4, bottom). It’s still on my “to-do” list to connect it to the Aptina MT9D131 camera and do some video streaming.

Brandsma believes that “books tell a lot about a person.” Photo 5 shows some books he uses when designing and or programming his projects.

Brandsma_books

Photo 5—A few of Brandsma’s “go-to” books are shown.

The technical difficulty of the books differs a lot. Electronica echt niet moeilijk (Electronics Made Easy) is an entry-level book that helped me understand the basics of electronics. On the other hand, the books about operating systems and the C++ programming language are certainly of a different level.

An article about Brandsma’s Sun Chaser GPS Reference Station is scheduled to appear in Circuit Cellar’s June issue.

Compact Computer-on-Module

ADLINKThe cExpress-HL computer-on-module (COM) utilizes an Intel Core processor (formerly known as Haswell-ULT) to provide a compact, high-performance COM solution. The cExpress-HL is well suited for embedded systems in medical, digital signage, gaming, video conferencing, and industrial automation that require a high-performance CPU and graphics, but are constrained by size or thermal management requirements.

The cExpress-HL features a mobile 4th Generation Intel Core i7/i5/i3 processor at 1.7 to 3.3 GHz with Intel HD Graphics 5000 (GT3). The COM delivers high graphics performance while still keeping thermal design power (TDP) below 15 W. Intel’s system-on-chip (SoC) solution has a small footprint that enables it to fit onto the 95 mm × 95 mm COM.0 R2.0 Type 6. The COM provides rich I/O and wide-bandwidth data throughput, including three independent displays (two DDI channels and one LVDS), four PCIe x1 or one PCIe x4 (Gen2), four SATA 6 Gb/s, two USB 3.0 ports, and six USB 2.0 ports.

The cExpress-HL is equipped with ADLINK’s Smart Embedded Management Agent (SEMA), which includes a watchdog timer, temperature and other board information monitoring, and fail-safe BIOS support. SEMA enables users to monitor and manage stand-alone, connected, or remote systems through a cloud-based interface.
Contact ADLINK for pricing.

ADLINK Technology, Inc.
www.adlinktech.com

Q&A: Robotics Mentor and Champion

Peter Matteson, a Senior Project Engineer at Pratt & Whitney in East Hartford, CT, has a passion for robotics. We recently discussed how he became involved with mentoring a high school robotics team, the types of robots the team designs, and the team’s success.—Nan Price, Associate Editor

 

NAN: You mentor a FIRST (For Inspiration and Recognition of Science and Technology) robotics team for a local high school. How did you become involved?

Peter Matteson

Peter Matteson

PETER: I became involved in FIRST in late 2002 when one of my fraternity brothers who I worked with at the time mentioned that FIRST was looking for new mentors to help the team the company sponsored. I was working at what was then known as UTC Power (sold off to ClearEdge Power Systems last year) and the company had sponsored Team 177 Bobcat Robotics since 1995.

After my first year mentoring the kids and experiencing the competition, I got hooked. I loved the competition and strategy of solving a new game each year and designing and building a robot. I enjoyed working with the kids, teaching them how to design and build mechanisms and strategize the games.

The FIRST team’s 2010 robot is shown.

The FIRST team’s 2010 robot is shown.

A robot’s articulating drive train is tested  on an obstacle (bump) at the 2010 competition.

A robot’s articulating drive train is tested on an obstacle (bump) at the 2010 competition.

NAN: What types of robots has your team built?

A temporary control board was used to test the drive base at the 2010 competition.

A temporary control board was used to test the drive base at the 2010 competition.

PETER: Every robot we make is purposely built for a specific game the year we build it. The robots have varied from arm robots with a 15’ reach to catapults that launch a 40” diameter ball, to Frisbee throwers, to Nerf ball shooters.

They have varied in drive train from 4 × 4 to 6 × 6 to articulating 8 × 8. Their speeds have varied from 6 to 16 fps.

NAN: What types of products do you use to build the robots? Do you have any favorites?

PETER: We use a variant of the Texas Instruments (TI) cRIO electronics kit for the controller, as is required per the FIRST competition rules. The motors and motor controllers we use are also mandated to a few choices. We prefer VEX Robotics VEXPro Victors, but we also design with the TI Jaguar motor controllers. For the last few years, we used a SparkFun CMUcam webcam for the vision system. We build with Grayhill encoders, various inexpensive limit switches, and gyro chips.

The team designed a prototype minibot.

The team designed a prototype minibot.

For pneumatics we utilize compressors from Thomas and VIAIR. Our cylinders are primarily from Bimba, but we also use Parker and SMC. For valves we use SMC and Festo. We usually design with clipart plastic or stainless accumulator tanks. Our gears and transmissions come from AndyMark, VEX Robotics’s VEXPro, and BaneBots.

The AndyMark shifter transmissions were a mainstay of ours until last year when we tried the VEXPro transmissions for the first time. Over the years, we have utilized many of the planetary transmissions from AndyMark, VEX Robotics, and BaneBots. We have had good experience with all the manufacturers. BaneBots had a shaky start, but it has vastly improved its products.

We have many other odds and ends we’ve discovered over the years for specific needs of the games. Those are a little harder to describe because they tend to be very specific, but urethane belting is useful in many ways.

NAN: Has your team won any competitions?

Peter’s FIRST team is pictured at the 2009 championship at the Georgia Dome in Atlanta, GA. (Peter is standing fourth from the right.)

Peter’s FIRST team is pictured at the 2009 championship at the Georgia Dome in Atlanta, GA. (Peter is standing fourth from the right.)

PETER: My team is considered one of the most successful in FIRST. We have won four regional-level competitions. We have always shined at the competition’s championship level when the 400 teams from the nine-plus countries that qualify vie for the championship.

In my years on the team, we have won the championship twice (2007 and 2010), been the championship finalist once (2011), won our division, made the final four a total of six times (2006–2011), and were division finalists in 2004.

A FIRST team member works on a robot “in the pits” at the 2011 Hartford, CT, regional competition.

A FIRST team member works on a robot “in the pits” at the 2011 Hartford, CT, regional competition.

Team 177 was the only team to make the final four more than three years in a row, setting the bar at six consecutive trips. It was also the only team to make seven trips to the final four, including in 2001.

NAN: What is your current occupation?

PETER: I am a Senior Project Engineer at Pratt & Whitney. I oversee and direct a team of engineers designing components for commercial aircraft propulsion systems.

NAN: How and when did you become interested in robotics?

PETER: I have been interested in robotics for as long as I can remember. The tipping point was probably when I took an industrial robotics course in college. That was when I really developed a curiosity about what I could do with robots.

The industrial robots course started with basic programming robots for tasks. We had a welding robot we taught the weld path and it determined on its own how to get between points.

We also worked with programming a robot to install light bulbs and then determine if the bulbs were working properly.

In addition to practical labs such as those, we also had to design the optimal robot for painting a car and figure out how to program it. We basically had to come up with a proposal for how to design and build the robot from scratch.

This robot from the 2008 competition holds a 40” diameter ball for size reference.

This robot from the 2008 competition holds a 40” diameter ball for size reference.

NAN: What advice do you have for engineers or students who are designing robots or robotic systems?

PETER: My advice is to clearly set your requirements at the beginning of the project and then do some research into how other people have accomplished them. Use that inspiration as a stepping-off point. From there, you need to build a prototype. I like to use wood, cardboard, and other materials to build prototypes. After this you can iterate to improve your design until it performs exactly as expected.

Energy-Measurement AFEs

Microchip_MCP3913The MCP3913 and the MCP3914 are Microchip Technology’s next-generation family of energy-measurement analog front ends (AFEs). The AFEs integrate six and eight 24-bit, delta-sigma ADCs, respectively, with 94.5-dB SINAD, –106.5-dB THD, and 112-dB Spurious-Free Dynamic Range (SFDR) for high-accuracy signal acquisition and higher-performing end products.

The MCP3914’s two extra ADCs enable the monitoring of more sensors with one chip, reducing its cost and size. The programmable data rate of up to 125 ksps with low-power modes enables designers to scale down for better power consumption or to use higher data rates for advanced signal analysis (e.g., calculating harmonic content).

The MCP3913 and the MCP3914 improve application performance and provide flexibility to adjust the data rate to optimize each application’s rate of performance vs power consumption. The AFEs feature a CRC-16 checksum and register-map lock, for increased robustness. Both AFEs are offered in 40-pin uQFN packages. The MCP3913 adds a 28-pin SSOP package option.

The MCP3913 and the MCP3914 AFEs cost $3.04 each in 5,000-unit quantities. Microchip Technology also announced the MCP3913 Evaluation Board and the MCP3914 Evaluation Board, two new tools to aid in the development of energy systems using these AFEs. Both evaluation boards cost $99.99.

Microchip Technology, Inc.
www.microchip.com

HMI Development on Intelligent Displays

4dsystems_HRES4D Systems and Future Technology Devices International Limited (FTDI) (aka, FTDI Chip) recently introduced the 4DLCD-FT843. The intelligent display solution incorporates FTDI Chip’s FT800 Embedded Video Engine (EVE) with the subsequent introduction of two additional products. This combined product gives design engineers a foundation on which to quickly and easily construct human-machine interfaces (HMIs).

The first of these products is the ADAM (Arduino Display Adaptor Module). This 47.5-mm × 53.4-mm Arduino-compatible shield permits communication between the Arduino via the SPI. The shield is suitable for use with Arduino Uno, Due, Duemilanove, Leonardo, Mega 1280/2560, and Pro 5V. The shield’s micro-SD card provides the Arduino-based display system with ample data storage. The 4DLCD-FT843 can use the micro-SD card to retrieve objects (e.g., images, sounds, fonts, etc.). Drawing power from the Arduino’s 5-V bus, the ADAM regulates the 4DLCD-FT843’s supply to 3.3 V. The FT800 EVE controller can handle many of the graphics functions that would otherwise need to be managed by the Arduino.

The ADAM is complemented by the 4DLCD-FT843-Breakout. With a 26.5-mm × 12-mm footprint, this simple breakout module enables the 4DLCD-FT843 to be attached to a general host or breadboard for prototyping purposes. It features a 10-way FPC connection for attachment with the 4DLCD-FT843 along with a 10-way, 2.54-mm pitch male pin header that enables it to directly connect to the host board. Both products support a –10°C-to-70°C operational temperature range.

The EVE-driven 4DLCD-FT843 has a 4.3” TFT QWVGA display with a four-wire resistive touchscreen. It features a 64-voice polyphonic sound synthesizer, a mono PWM audio output, a programmable interrupt controller, a PWM dimming controller for the display’s backlight, and a flexible ribbon connector.

Contact 4D Systems or FTDI Chip for pricing.

4D Systems
www.4dsystems.com.au

Future Technology Devices International Limited (FTDI) (aka, FTDI Chip)
www.ftdichip.com

Three-Axis Magnetometer Sensor

SaeligThe IST8301C is a single-chip three-axis digital magnetometer sensor that is housed in a 2.5-mm × 2.5-mm × 1-mm, 12-pin ball-grid array (BGA) package. The integrated chip includes three-axis magnetic sensors with an ASIC controller.

The IST8301C outputs 13-bit data over a ±1,000-µT magnetic field range in a fast-mode 400-kHz I2C digital output. The compact form factor is easily surface mounted and is well suited for high-volume production consumer electronics, navigation systems, and magnetometers.

The IST8301C embeds 32 slots of 16-bit first in, first out (FIFO) data for each of three output channels X, Y, Z. Since the host processor does not need to continuously read data from a sensor, the FIFO’s “wake up only as needed” operation enables consistent system-power saving. Functioning on 2.4 V with a 10-uA standby current and full operation at 300 uA, increased battery life can be attained in many portable applications.

The IST8301C offers a ±1° heading accuracy and a ±10-gauss magnetic field range. The sensor includes anti-offset and anti-temperature to help eliminate errors caused by temperature and factory mismatch.

Contact Saelig for pricing.

Saelig Co., Inc.
www.saelig.com

ARM mbed Platform for Bluetooth Smart Applications

OLYMPUS DIGITAL CAMERAThe nRF51822-mKIT simplifies and accelerates the prototyping process for Bluetooth Smart sensors connecting to the Internet of Things (IoT). The platform is designed for fast, easy, and flexible development of Bluetooth Smart applications.

The nRF51822 system-on-chip (SoC) combines a Bluetooth v4.1-compliant 2.4-GHz multiprotocol radio with an ARM Cortex-M0 CPU core on a single chip optimized for ultra-low-power operation. The SoC simplifies and accelerates the prototyping process for Bluetooth Smart sensors connecting to the IoT.

The nRF51822-mKIT’s features include a Bluetooth Smart API, 31 pin-assignable general-purpose input/output (GPIO), a CMSIS-DAP debugger, Programmable Peripheral Interconnect (PPI), and the ability to run from a single 2032 coin-cell battery.

Through mbed, the kit is supported by a cloud-based approach to writing code, adding libraries, and compiling firmware. A lightweight online IDE operates on all popular browsers running on Windows, Mac OSX, iOS, Android, and Linux OSes. Developers can use the kit to access a cloud-based ARM RVDS 4.1 compiler that optimizes code size and performance.

The nRF51822-mKIT costs $59.95.

Nordic Semiconductor ASA
www.nordicsemi.com

High-Speed CMOS DDR SDRAMs

AllianceMemoryThe AS4C4M16D1-5TIN, the AS4C8M16D1-5TIN, the AS4C16M16D1-5TIN, and the AS4C32M16D1-5TIN are high-speed CMOS double data rate synchronous DRAMs (DDR SDRAMs). The devices feature densities of 64 MB (AS4C4M16D1-5TIN), 128 MB (AS4C8M16D1-5TIN), 256 MB (AS4C16M16D1-5TIN), and 512 MB (AS4C32M16D1-5TIN) with a –40°C to 85°C industrial temperature range.

The DDR SDRAMs provide reliable drop-in, pin-for-pin-compatible replacements for industrial, medical, communications, and telecommunications products requiring high memory bandwidth. The devices are well-suited for high performance in PC applications. Internally configured as four banks of 1M, 2M, 4M, or 8M word × 16 bits with a synchronous interface, the DDR SDRAMs operate from a single 2.5-V (± 0.2 V) power supply and are lead- and halogen-free.

The AS4C4M16D1-5TIN, the AS4C8M16D1-5TIN, the AS4C16M16D1-5TIN, and the AS4C32M16D1-5TIN feature a 200-MHz clock rate and are available in a 66-pin TSOP II package with a 0.65-mm pin pitch. The 128-, 256-, and 512-MB devices are also available in a TFBGA package.

The DDR SDRAMs provide programmable read or write burst lengths of 2, 4, or 8. An auto pre-charge function provides a self-timed row pre-charge initiated at the end of the burst sequence. Easy-to-use refresh functions include auto- or self-refresh. A programmable mode register enables the system to choose a suitable mode for maximum performance.
Pricing for the AS4C4M16D1-5TIN, the AS4C8M16D1-5TIN, the AS4C16M16D1-5TIN, and the AS4C32M16D1-5TIN starts at $0.90 per piece.

Alliance Memory, Inc.
www.alliancememory.com

Miniature PECL and LVDS Oscillators

PrecisionDevicesThe PDI Model LV5 and PE5 Series of oscillators provide precision timing in a 3.2-mm × 5-mm ceramic hermetically sealed package. The LV5 is a low-voltage differential signaling (LVDS) ocsillator. The PE5 is a PECL oscillator.

These high-performance clock oscillators offer low integrated phase jitter (0.2 pS for the LV5 and 0.3 pS for the PE5). They are available in frequencies up to 200 MHz and feature a –40°C to 85°C industrial temperature range. Stabilities can be held down to ±25 ppm (depending on temperature range).

Contact Precision Devices for pricing.

Precision Devices, Inc.
www.pdixtal.com

Traveling With a “Portable Workspace”

As a freelance engineer, Raul Alvarez spends a lot of time on the go. He says the last four or five years he has been traveling due to work and family reasons, therefore he never stays in one place long enough to set up a proper workspace. “Whenever I need to move again, I just pack whatever I can: boards, modules, components, cables, and so forth, and then I’m good to go,” he explains.

Raul_Alvarez_Workspace _Photo_1

Alvarez sits at his “current” workstation.

He continued by saying:

In my case, there’s not much of a workspace to show because my workspace is whichever desk I have at hand in a given location. My tools are all the tools that I can fit into my traveling backpack, along with my software tools that are installed in my laptop.

Because in my personal projects I mostly work with microcontroller boards, modular components, and firmware, until now I think it didn’t bother me not having more fancy (and useful) tools such as a bench oscilloscope, a logic analyzer, or a spectrum analyzer. I just try to work with whatever I have at hand because, well, I don’t have much choice.

Given my circumstances, probably the most useful tools I have for debugging embedded hardware and firmware are a good-old UART port, a multimeter, and a bunch of LEDs. For the UART interface I use a Future Technology Devices International FT232-based UART-to-USB interface board and Tera Term serial terminal software.

Currently, I’m working mostly with Microchip Technology PIC and ARM microcontrollers. So for my PIC projects my tiny Microchip Technology PICkit 3 Programmer/Debugger usually saves the day.

Regarding ARM, I generally use some of the new low-cost ARM development boards that include programming/debugging interfaces. I carry an LPC1769 LPCXpresso board, an mbed board, three STMicroelectronics Discovery boards (Cortex-M0, Cortex-M3, and Cortex-M4), my STMicroelectronics STM32 Primer2, three Texas Instruments LaunchPads (the MSP430, the Piccolo, and the Stellaris), and the following Linux boards: two BeagleBoard.org BeagleBones (the gray one and a BeagleBone Black), a Cubieboard, an Odroid-X2, and a Raspberry Pi Model B.

Additionally, I always carry an Arduino UNO, a Digilent chipKIT Max 32 Arduino-compatible board (which I mostly use with MPLAB X IDE and “regular” C language), and a self-made Parallax Propeller microcontroller board. I also have a Wi-Fi 3G TP-LINK TL-WR703N mini router flashed   with OpenWRT that enables me to experiment with Wi-Fi and Ethernet and to tinker with their embedded Linux environment. It also provides me Internet access with the use of a 3G modem.

Raul_Alvarez_Workspace _Photo_2

Not a bad set up for someone on the go. Alvarez’s “portable workstation” includes ICs, resistors, and capacitors, among other things. He says his most useful tools are a UART port, a multimeter, and some LEDs.

In three or four small boxes I carry a lot of sensors, modules, ICs, resistors, capacitors, crystals, jumper cables, breadboard strips, and some DC-DC converter/regulator boards for supplying power to my circuits. I also carry a small video camera for shooting my video tutorials, which I publish from time to time at my website (www.raulalvarez.net). I have installed in my laptop TechSmith’s Camtasia for screen capture and Sony Vegas for editing the final video and audio.

Some IDEs that I have currently installed in my laptop are: LPCXpresso, Texas Instruments’s Code Composer Studio, IAR EW for Renesas RL78 and 8051, Ride7, Keil uVision for ARM, MPLAB X, and the Arduino IDE, among others. For PC coding I have installed Eclipse, MS Visual Studio, GNAT Programming Studio (I like to tinker with Ada from time to time), QT Creator, Python IDLE, MATLAB, and Octave. For schematics and PCB design I mostly use CadSoft’s EAGLE, ExpressPCB, DesignSpark PCB, and sometimes KiCad.

Traveling with my portable rig isn’t particularly pleasant for me. I always get delayed at security and customs checkpoints in airports. I get questioned a lot especially about my circuit boards and prototypes and I almost always have to buy a new set of screwdrivers after arriving at my destination. Luckily for me, my nomad lifestyle is about to come to an end soon and finally I will be able to settle down in my hometown in Cochabamba, Bolivia. The first two things I’m planning to do are to buy a really big workbench and a decent digital oscilloscope.

Alvarez’s article “The Home Energy Gateway: Remotely Control and Monitor Household Devices” appeared in Circuit Cellar’s February issue. For more information about Alvarez, visit his website or follow him on Twitter @RaulAlvarezT.

RS-232 Serial Adapter for Android Devices

ACCESSThe ANDROID-232 is a USB serial interface board that enables you to control legacy RS-232 devices from your Android devices. The board is well suited for POS, gaming systems, retail, hospitality, automation, kiosks, defense industries, lighting, or any other application requiring the connection of RS-232 serial devices to an Android-compatible system.

The ANDROID-232 uses the Android Open Accessory protocol to “convince” an Android device that its on-board USB port (normally limited to USB slave or OTG modes) is actually an RS-232 port. This two-way data port enables external hardware to control the Android unit or the Android unit to control external hardware.

The ANDROID-232’s key features include an Android USB 2.0 full-speed host-to-industry-standard RS-232 DB9M serial port; support for a UART interface with RX, TX, RTS, and CTS; a 5,512-byte RX buffer size; a 256-byte TX buffer size; ±15-kV ESD protection on USB data lines and all RS-232 signals; status and fault LEDs including external power, charging status, and USB status; a Type-A USB connector; a latching 5-V external power input connector with an external regulated power supply; a –40°C-to-85°C standard industrial operating temperature; and RoHS compliance.

The board includes an Android sample program with source code. This program enables you to verify proper operation of the ANDROID-232 device, including sending and receiving RS-232 data. The ANDROID-232’s Python test program can cooperate with the Android sample program to verify proper receipt of transmitted data.

The ANDROID-232 costs $139.

ACCES I/O Products, Inc.
www.accesio.com