EOG-Controlled Video Game

Eyes as Interface

There’s much be to learned about how electronics can interact with biological signals—not only to record, but also to see how they can be used as inputs for control applications. With ongoing research in fields such as virtual reality and prosthetics, new systems are being developed to interpret different types of signals for practical applications. Learn how these three Cornell graduates use electrooculography (EOG) to control a simple video game by measuring eye movements.

By Eric Cole, Evan Mok and Alex Huang

The human eye naturally acts as a dipole, in which the retina at the back of the eye is negatively charged, and the cornea at the front of the eye is positively charged. EOG is a recording technique that measures this potential difference, and can be used to

Figure 1
Electrode placement for recording. An Ag-AgCl (silver-silver chloride) electrode was placed at each of the labeled points. Points A and B record the EOG signal for the right and left eyes, and point C provides a ground reference.

quantify eye movement [1]. A typical electrode placement pattern for EOG is shown in Figure 1. Each of the electrodes A and B records a voltage related to eye movement, and an electrode at point C serves as a ground reference.

When a user looks left, the cornea is close to electrode B and it records a positive voltage, while the retina is closer to electrode A, yielding a negative voltage. Similarly, looking right produces a negative voltage at B and a positive voltage at A. The difference between VB and VA relative to ground at C changes monotonically with gaze direction, and can be reliably used to model horizontal eye movement.

System Overview

The system we designed uses eye movements to play a video game on a display screen. Electrodes are placed on a player’s head to record only the horizontal EOG signal as shown in Figure 2. This signal is then filtered and amplified via an analog circuit and sent to an ADC on a Microchip Technology PIC32 microcontroller (MCU) (Figure 3). The PIC32 MCU stores the reading as a digital value and uses it to control a cursor on an LCD display screen. A program on the PIC32 continually displays obstacles that move across the screen, and the player moves his or her eyes to control the cursor and avoid obstacles.

Figure 2
Characterization of EOG signal. An example signal output is shown for a gain of approximately 885.

Figure 3
System overview. “Eye recording” is accomplished with the raw electrode signal.

This system is entirely powered without connection to an AC power source, instead using a 9 V battery to provide power for amplification and a chargeable power source to power the PIC32. This choice of a power source was important, because it enforces necessary safety considerations for biomedical recording. Connecting a high voltage source to a human user and accidentally completing a circuit path to AC ground could result in serious injury, so great care was taken to use battery power for this project.

A secondary oscilloscope program was also necessarily designed to satisfy a key safety need: The ability to view the recorded EOG signal and test the recording hardware while the circuit is isolated. A normal oscilloscope cannot be used for this purpose for the reasons stated earlier. Care was also taken to apply and fasten the electrodes properly before every session.

Recording and Application

Three Ag-AgCl (silver-silver chloride) electrodes are placed around the eyes using a skin-safe adhesive gel—one beside each eye, and one on the forehead as a ground reference—at points A, B, and C respectively, in Figure 1. These electrodes provide the gateway between the biological signal and the digital world, detecting the voltage generated by ions at the skin surface and transducing it into an equivalent electron-based signal.

This voltage is generated directly at the eye, and has some attenuation through the skin surface. A typical magnitude of the raw EOG signal is several millivolts. The voltage readings from the two eye electrodes are sent to a Texas Instruments (TI) INA121 differential amplifier, which amplifies the difference between the two input signals. This yields a negative or positive voltage based on direction of eye movement. The INA121 provides low noise, a high common-mode rejection ratio, and is suitable for the high-input impedance requirement associated with recording biological signals. Figure 4 shows the full schematic of the implementation.

A second amplification stage using a TI LM358-based balanced subtractor configuration provides further amplification. This stage reduces the DC voltage component output from the differential amplifier, while further amplifying the difference to a range of 0 to 3.3 V—the scale allowed by the PIC32 MCU’s on-chip ADC. The resulting signal is a voltage centered at approximately 1.6 V when the user looks straight, with about a 1 V increase or decrease when the user looks left or right, respectively. …

Read the full article in the July 348 issue of Circuit Cellar
(Full article word count: 3023 words; Figure count: 6 Figures.)

Don’t miss out on upcoming issues of Circuit Cellar. Subscribe today!

Note: We’ve made the October 2017 issue of Circuit Cellar available as a free sample issue. In it, you’ll find a rich variety of the kinds of articles and information that exemplify a typical issue of the current magazine.

July Circuit Cellar: Sneak Preview

The July issue of Circuit Cellar magazine is out next week! This 84-page publication will make a satisfying thud sound when it lands on your desk and it’s crammed full of excellent embedded electronics articles prepared for you.

Not a Circuit Cellar subscriber?  Don’t be left out! Sign up today:


Here’s a sneak preview of July 2019 Circuit Cellar:


Embedded Computing
in Railway Systems
Railway systems keep getting more advanced. On both the control side and passenger entertainment side, embedded computers and power supplies play critical roles. Railway systems need sophisticated networking, data collection and real-time control, all while meeting safety standards. Circuit Cellar Chief Editor Jeff Child looks at the latest technology trends and products relevant to railway applications.

Product Focus:
IoT Interface Modules
The fast growing IoT phenomenon is driving demand for highly integrated modules designed for the IoT edge. Feeding those needs, a new crop of IoT modules have emerged that offer pre-certified solutions that are ready to use. This Product Focus section updates readers on this technology trend and provides a product album of representative IoT modules.


FPGA Signal Processing
Offering the dual benefits of powerful signal processing and system-level integration, FPGAs have become a key technology for embedded system developers. Makers of chip and board-level FPGA products are providing complete solutions to enable developers to meet their application needs. Circuit Cellar Chief Editor Jeff Child explores the latest technology trends and product developments in FPGA signal processing.

Macros for AVR Assembler Programming
The AVR microcontroller instruction set provides a simplicity that makes it good for learning the root principles of machine programming. There’s also a rich set of macros available for the AVR that ease assembler-level programming. In this article, Wolfgang Matthes steps you through these principles, with the goal of helping programmers “think low-level, write high-level” when they approach embedded systems software development.

Inrush Current Limiters in Action
At the moment a high-power system is switched on, high loads can result in serious damage—even when the extra load is only for short time. Inrush current limiters (ICLs) can help prevent these issues. In this article, TDK Electronics’ Matt Reynolds examines ICLs based on NTC and PTC thermistors, discussing the underlying technology and the device options.

A Look at Cores with TrustZone-M
It’s not so easy to keep up with all the new security features on the latest and greatest embedded processors—especially while you’re busy focusing on the more fundamental and unique aspects of your design. In this article, Colin O’Flynn helps out by examining the new processor cores using TrustZone-M, a feature that helps you secure even low-cost and lower power system designs.


Energy Monitoring Part 2
In Part 1 of this article series, George Novacek began describing an MCU-based system he built to monitor his household energy. Here, he continues that discussion, this time focusing on the electrical power tracking module. As the story shows, he stuck to a design challenge of building the system with as many components he already had in his component bins.

Variable Frequency Drive Part 1
Modern appliances claim to be more efficient, but they’re certainly not designed to last as long as older models. In this project article, Brian Millier describes how he reused subsystems from a defunct modern washing machine to power his bandsaw. The effort provides valuable insights on how to make use of the complete 3-phase Variable Frequency Drive (VFD) borrowed from the washing machine.


Windless Wind Chimes (Part 2)
In part 1 of this article series, Jeff Bachiochi built a system to simulate breezes randomly playing the sounds of suspended wind chimes. In part 2 the effort evolves into a less random, more orchestrated project. Jeff decided this time to craft a string of chromatically tuned chimes, similar to what an orchestra might use so the project could be used to play music. The project relies on MIDI, an industry standard music technology protocol designed to create and share music and artistic works.

Building a Smart Frying Pan
There’s almost no limit to what an MCU can be used for—-including objects that previously had no electronics at all. In this article, learn how Cornell University graduate Joseph Dwyer build a Microchip PIC32 MCU-based system that wirelessly measures and controls the temperature of a pan on a stove. The system improves both the safety and reliability of cooking on the stove, and has potentially interesting commercial applications.

EOG-Controlled Video Game
There’s much be to learned about how electronics can interact with biological signals—not only to record, but also to see how they can be used as inputs for control applications. With ongoing research in fields such as virtual reality and prosthetics, new systems are being developed to interpret different types of signals for practical applications. Learn how Cornell graduates  Eric Cole, Evan Mok and Alex Huang use electrooculography (EOG) to control a simple video game by measuring eye movement.

Catalog of 125 Open-Spec Hacker Boards: Spring 2019 Edition!

Circuit Cellar’s sister website Linuxgizmos,com has posted its annual Spring edition catalog of hacker-friendly, open-spec SBCs that run Linux or Android.

The catalog includes summaries of 125 community-backed Linux/Android hacker boards under $200 are listed in alpha order.

They list specs and lowest available pricing recorded in the last two weeks of May 2019, with products either shipping or available for pre-order with expected ship date by the end of June.


June Circuit Cellar: Sneak Preview

The June issue of Circuit Cellar magazine is out next week!. We’ve been tending our technology crops to bring you a rich harvest of in-depth embedded electronics articles. We’ll have this 84-page magazine brought to your table very soon..

Not a Circuit Cellar subscriber?  Don’t be left out! Sign up today:


Here’s a sneak preview of June 2019 Circuit Cellar:


Integrated PCB Design Tools
After decades of evolving their PCB design tool software packages, the leading tool vendors have the basics of PCB design nailed down. In recent years, these companies have continued to come up with new enhancements to their tool suites, addressing a myriad of issues related to not just the PCB design itself, but the whole process surrounding it. Circuit Cellar Chief Editor Jeff Child looks at the latest integrated PCB design tool solutions.

dB for Dummies: Decibels Demystified
Understanding decibels—or dB for short—may seem intimidating. Frequent readers of this column know that Robert uses dB terms quite often—particularly when talking about wireless systems or filters. In this article, Robert Lacoste discusses the math underlying decibels using basic concepts. The article also covers how they are used to express values in electronics and even includes a quiz to help you hone your decibel expertise.

Understanding PID
As a means for implementing feedback control systems, PID is an important concept in electronics engineering. In this article, Stuart Ball explains how PID can be applied and explains the concept by focusing on a simple circuit design.


Sensor Connectivity Trends
While sensors have always played a key role in embedded systems, the exploding Internet of Things (IoT) phenomenon has pushed sensor technology to the forefront. Any IoT implementation depends on an array of sensors that relay input back to the cloud. Circuit Cellar Chief Editor Jeff Child dives into the latest technology trends and product developments in sensors with an emphasis on their connectivity aspects.

Bluetooth Mesh (Part 3)
In this next part of his article series on Bluetooth mesh, Bob Japenga looks at how to create secure provisioning for a Bluetooth Mesh network without requiring user intervention. He takes a special look at an attack which Bluetooth’s asymmetric key encryption is vulnerable to called Man-in-the-Middle.


Product Focus: AC-DC Converters
To their peril, embedded system developers often treat their choice of power supply as an afterthought. But choosing the right AC-DC converter is critical to the ensuring your system delivers power efficiently to all parts of your system. This Product Focus section updates readers on these trends and provides a product album of representative AC-DC converter products.

Energy Monitoring (Part 1)
The efficient use of energy is a topic moving ever more front and center these days as climate change and energy costs begin to affect our daily lives. Curious to discover how efficient his own energy consumption was, George Novacek built an MCU-based system to monitor his household energy. And, in order to make sure this new device wasn’t adding more energy use, he chose to make the energy monitoring system solar-powered.

Building a PoE Power Subsystem
Power-over-Ethernet (PoE) allows a single cable to provide both data interconnection and power to devices. In this article, Maxim Integrated’s  and Maxim Integrated’s Thong Huynh and Suhei Dhanani explore the key issues involved in implementing rugged PoE systems. Topics covered include standards compliance, interface controller selection, DC-DC converter choices and more.

Taming Your Wind Turbine
While you can buy off-the-shelf wind power generators these days, they tend to get bad reviews from users. The problem is that harnessing wind energy takes some “taming” of the downstream electronics. In this article, Alexander Pozhitkov discusses his characterization project for a small wind turbine. This provides a guide for designing your own wind energy harvesting system.


Windless Wind Chimes (Part 1)
Wind chimes make a pleasant sound during the warm months when windows are open. But wouldn’t it be nice to simulate those sounds during the winter months when your windows are shut? In part 1 of this project article, Jeff Bachiochi builds a device that simulates a breeze randomly playing suspended wind chimes. Limited to the standard 5-note pentatonic chimes, this device is based on a Microchip PIC18 low power microcontroller.

GPS Guides Robotic Car
In this project article, Raul Alvarez-Torrico builds a robotic car that navigates to a series of GPS waypoints. Using the Arduino UNO for a controller, the design is aimed at robotics beginners that want to step things up a notch. In the article, Raul discusses the math, programing and electronics hardware choices that went into this project design.

Haptic Feedback Electronic Travel Aid
Time-of-flight sensors have become small and affordable in the last couple years. In this article, learn how Cornell graduates Aaheli Chattopadhyay, Naomi Hess and Jun Ko detail creating a travel aid for the visually impaired with a few time-of-flight sensors, coin vibration motors, an Arduino Pro Mini, a Microchip PIC32 MCU, a flashlight and a sock.

Whiskey-Lake U Processor Rides COM Express Type 6 Module

TQ Systems has released a COM Express Compact Type 6 module TQMx80UC based on the 8th generation Intel Core Mobile Processors code named “Whiskey-Lake U”. This module is well suited for industrial controllers, robotics applications, medical devices and point-of-sales. Depending on the required functionality and computing power, several CPU variants (i7, i5, i3, Pentium, Celeron) with two or four cores can be selected. With a thermal power loss of 15 W TDP, four cores are now available for the first time in this performance class (previously two for the 7th generation U series).

The memory interface is equipped with the fast DDR4-2400 technology. The memory capacity can be selected between 4 GB and 64 GB depending on the SO-DIMM modules used. Up to nine PCI Express lanes (Gen3; 8 GHz) are available for connecting up to five peripheral devices and can be flexibly configured in the BIOS. For the first time, the new USB 3.1 Gen2 standard is supported, which allows transfer rates of up to 10 Gbit/s.

Four high-speed interfaces are available for this purpose. In addition, eMMC flash in sizes between 8 GB and 128 GB is available for the first time on the module. The COM Express Compact Module TQMx80UC with its dimensions of 95 mm x 95 mm and Type 6 pinout conforms to PICMG COM.0 R3.0. It is supported by the new TQ mainboard MB-COME6-3. Together with a 11 mm high heatspreader and a heatsink, the combination of boards results in an effective evaluation platform.

TQ Systems | www.tq-group.com



PIC MCU Development Board for Cloud IoT Core

Microchip Technology has announced an IoT rapid development board for Google Cloud IoT Core that combines a low-power PIC MCU, CryptoAuthentication secure element IC and fully certified Wi-Fi network controller. The solution provides a simple way to connect and secure PIC MCU-based applications. It’s designed to remove the added time, cost and security vulnerabilities that come with large software frameworks and RTOS.
As part of Microchip’s extended partnership with Google Cloud, the PIC-IoT WG Development Board enables PIC MCU designers to easily add cloud connectivity to next-generation products using a free online portal at www.PIC-IoT.com. Once connected, developers can use Microchip’s MPLAB Code Configurator (MCC) rapid development tool to develop, debug and customize their application.

The board includes:

  • eXtreme Low-Power (XLP) PICMCU with integrated Core Independent Peripherals: Well suited for battery-operated, real-time sensing and control applications, the PIC24FJ128GA705 MCU provides the simplicity of the PIC architecture with added memory and advanced analog integration. With the latest Core Independent Peripherals (CIPs) designed to handle complex applications with less code and decreased power consumption, the device provides the ideal combination of performance with extremely low power consumption.
  • Secure element to protect the root of trust in hardware: The ATECC608A CryptoAuthentication device provides a trusted and protected identity for each device that can be securely authenticated. ATECC608A devices come pre-registered on Google Cloud IoT Core and are ready for use with zero-touch provisioning.
  • Wi-Fi connectivity to Google Cloud: The ATWINC1510 is an industrial-grade, fully certified IEEE 802.11 b/g/n IoT network controller that provides an easy connection to an MCU of choice via a flexible SPI interface. The module relieves designers from needing expertise in networking protocols.

Google Cloud IoT Core provides a fully managed service that enables designers to easily and securely connect, manage and ingest data from devices at a global scale. The platform collects, processes and analyzes data in real time to enable designers to improve operational efficiency in embedded designs.

The PIC-IoT WG development board is supported by the MPLAB X Integrated Development Environment (IDE) and MCC rapid prototyping tool. The board is compatible with more than 450 MikroElektronika Click boards that expand sensors and actuator options. Developers who purchase the kit will have access to an online portal for immediate visualization of their sensors’ data being published. Supported by complete board schematics and demo code, the PIC-IoT WG development board helps get customers to market quickly with differentiated IoT end products.

The PIC-IoT WG Development Board (AC164164) is available in volume production now for $29 each.

Microchip Technology | www.microchip.com

Catalog of 122 Open-Spec Linux Hacker Boards

Circuit Cellar’s sister website Linuxgizmos,com has posted its 2019 New Year’s edition catalog of hacker-friendly, open-spec SBCs that run Linux or Android. The catalog provides recently updated descriptions, specs, pricing, and links to details for all 122 SBCs.


Tiny MCU-Based Development Platform Hosts Dual USB Ports

Segger Microcontroller has introduced emPower-USB-Host, a compact low-cost development board. With two USB host ports, many applications using USB peripherals can be realized with little effort. Precompiled applications for barcode and smartcard readers, as well as POS displays, LTE sticks and USB to LAN adapters are available for download, including complete projects for Embedded Studio with source code of these applications. The applications are using Segger’s emUSB-Host software API, which makes accessing the different types of USB devices easy.
emPower-USB-Host uses the emLoad bootloader, pre-loaded into the flash of the MCU, to easily change applications in seconds using a USB flash drive. Development of custom applications is also supported. The board has a debug connector, providing full access to the NXP LPC54605J512 MCU with its Cortex-M4 core. Schematics and PCB layout of the board are available under a Creative Commons license. This way, the hardware can be used as a blueprint for custom devices using two USB host ports.

Segger Microcontroller | www.segger.com

Signature Analyzer Uses NXP MCU

Scope-Free Tester

Doing a signature analysis of a signal used to require an oscilloscope to display your results. In this article, Brian details how to build a free-standing tester using mostly just the internal peripherals of an NXP Arm microcontroller. He describes how the tester operates and how he implemented it.

By Brian Millier

When I was a teenager starting out in electronics, I longed to have as much test equipment as possible. At that stage in life, I couldn’t afford much beyond a multimeter. I remember seeing plans for a component tester in an electronics magazine. There weren’t many hobby electronics magazines back in the ‘60s, so it was probably Popular Electronics. This tester would provide a “signature” of most passive/active components by placing a small AC voltage across the component and measuring the resulting current. My memory of the circuit is hazy after all these years, but it was trivial: a 6.3 V filament transformer, a current sensing resistor and a few other passive components. However, the catch was that it required an oscilloscope to display the resulting voltage vs. current plot—in other words, the component’s signature. By the time I bought an oscilloscope about 10 years later, I had completely forgotten about this testing concept.

Today, test instruments are available that include a dedicated graphics display, instead of relying on an oscilloscope for display purposes. Having worked with Arm microcontrollers over the last few years,
I realized that I could implement such a free-standing tester using, in large part, just the internal MCU peripherals.

In this article I’ll describe how the tester operates, and how I implemented it using a Teensy 3.5 development module (containing an NXP MK64FX512VMD12 MCU) and featuring a FT800-based intelligent 4.3″ TFT touch-screen display.

Basic Theory of Operation

To obtain a signature of a given component, you need to place a variable voltage across it and measure the resulting current through it, at each voltage level. In many cases, the component’s normal operating mode will include both positive and negative voltages across it, so the tester must provide an AC voltage source. For most testing purposes you would use a sine wave voltage source because most AC calculations are done using sine waves. The value of this AC voltage source must be adjustable. I decided on six ranges between 0.5 V peak-peak and 20 V peak-peak. For measuring the voltage across the component, I used an instrumentation amplifier with three hardware gain ranges—plus three additional ranges based upon scaling in software.

To monitor current, it’s easiest to measure the voltage across a small value resistor placed in the ground return path, and then convert that to current using Ohm’s Law. Here too you need a range of current measurements. I chose to provide three hardware ranges—plus four additional ranges based on software scaling—between 1 mA and 100 mA.

You can’t just place an AC voltage of any given value across a component, and hope that the component will be able to handle that current without damage. You must place a resistor in series with the component to limit the current flow. That resistor may need to vary in value over several decades, depending on the component being tested. In my tester, I provide a switchable resistor bank with values covering a 1,000:1 range in decade steps.

Figure 1 is a block diagram of the basic tester circuitry. The user interface, touch-screen display and SD card data storage are not shown here. The MK64FX512VMD12 MCU’s 12-bit DAC A provides a sine wave signal that varies between 0 and 1.2 V over the full AC cycle. The programmable attenuator is an SPI pot device with 12-bit resolution. C1 is a decoupling capacitor, which shifts the (attenuated) unipolar DAC A output signal into a bipolar AC signal. This AC signal is amplified by a factor of 21 by an LM675 power amplifier IC. DAC B, along with some passive components, provide a software-adjustable offset voltage adjustment. The LM675 amplifier is needed to provide enough drive current to handle the higher current ranges—up to 100 mA.

This is a block diagram of the AC signal generation and Voltage/Current monitoring circuit.

Both the voltage and current are monitored using Texas Instruments (TI)instrumentation amplifier ICs. These contain input protection circuitry good to ±40 V. The various gains needed for both amplifiers are set by 1% resistors, which are switched by miniature reed relays. The instrumentation amplifier output voltages, representing voltage and current through the component under test, are fed to the two 16-bit ADCs present in the NXP MK64FX512VMD12 Arm MCU. The sine wave signal generated by the MCU can be set for frequencies of 20, 50 ,60, 100, 200 or 400 Hz.

Signature Analysis

The basic premise of signature analysis is that you obtain a signature of a component that is of questionable condition, and then compare it with a known-good component of the same value. Alternately, you can do the same comparison on a specific circuit node on two identical circuit boards/assemblies.. …

Read the full article in the August 337 issue of Circuit Cellar

Don’t miss out on upcoming issues of Circuit Cellar. Subscribe today!

Note: We’ve made the October 2017 issue of Circuit Cellar available as a free sample issue. In it, you’ll find a rich variety of the kinds of articles and information that exemplify a typical issue of the current magazine.

The Voting Results are in. We Have a Winner!

Circuit Cellar’s sister website LinuxGizmos.com has completed its 2018 hacker board survey, which ran on SurveyMonkey in partnership with Linux.com. Survey participants chose the new Raspberry Pi 3 Model B+, as the favorite board from among 116 community-backed SBCs that run Linux or Android and sell for under $200.
All 116 SBCs are summarized in LinuxGizmos’ recently updated hacker board catalog and feature comparison spreadsheet.


Deadline Extended to June 22 — Vote Now!

UPDATE: We’ve extended our 2018 reader survey on open-spec Linux/Android hacker boards through this Friday, June 22.   Vote now!

Circuit Cellar’s sister website LinuxGizmos.com has launched its fourth annual reader survey of open-spec, Linux- or Android-ready single board computers priced under $200. In coordination with Linux.com, LinuxGizmos has identified 116 SBCs that fit its requirements, up from 98 boards in its June 2017 survey.

Vote for your favorites from LG’s freshly updated catalog of 116 sub-$200, hacker-friendly SBCs that run Linux or Android, and you could win one of 15 prizes.

Check out LinuxGizmos’ freshly updated summaries of 116 SBCs, as well as its spreadsheet that compares key features of all the boards.

Explore this great collection of Linux SBC information. To find out how to participate in the survey–and be entered to win a free board–click here:




Target Boards for Renesas RX 32-bit MCUs

Renesas Electronics has announced three new Target Boards for the RX65N, RX130 and RX231 Microcontroller (MCU) Groups, each designed to help engineers jump start their home appliance, building and industrial automation designs. Priced below $30, the Target Boards lower the price threshold for engagement, allowing more system developers to make use of Renesas’ broad-based 32-bit RX MCU family.

The RX Target Boards provide an inexpensive entry point for embedded designers to evaluate, prototype and develop their products. Each board kit features an on-chip debugger tool that enables application design without requiring further tool investments. Through-hole pin headers provide access to all MCU signals pins, making it easy for users to interconnect to standard breadboards for fast prototyping.

The RX Target Board evaluation concept reuses the same PCB for all MCU variations. Since each member of the Renesas RX MCU Family has a common pin assignment, users experience a smooth transition between different RX Groups and RX Series using the same package version. In the case of the RX Target Boards, the widely used 100-pin LQFP package is on board.

The RX Target Boards offer everything designers need to start board and demo development, including a board circuit diagram and bill of materials, demo source code, user manual, and application notes. Additional Target Board variations will be released soon that will provide full coverage of the entire RX Family, from the low-power RX100 Series to the high-performance RX700 Series.

The RX65N MCU Group combines an enhanced RX CPU core architecture and 120 MHz operation to achieve processing performance of 4.34 CoreMark/MHz. The MCUs include an integrated Trusted Secure IP, enhanced, trusted flash functionality, and a human-machine interface (HMI) for industrial and network control systems operating at the edge of the Industrial Internet of Things (IIoT). The RX65N MCUs also include an embedded TFT controller and integrated 2D graphic accelerator with advanced features ideal for TFT displays designed into IIoT edge devices or system control applications. In addition, the RX65N MCUs include embedded communication-processing peripherals such as Ethernet, USB, CAN, SD host/slave interface and quad SPI.

The RX130 MCU Group provides 32 MHz operation with flash memory sizes up to 512 KB, and package sizes up to 100-pins to provide higher performance and compatibility with the RX231/RX230 Group of touch MCUs. The ultra-low power, low-cost RX130 Group adds higher responsiveness and functionality for touch-based applications requiring 3V or 5V system control and low power consumption. Featuring a new capacitive touch IP with improved sensitivity and robustness, and a comprehensive device evaluation environment, the new 32-bit RX130 MCUs are an ideal fit for devices designed with challenging, non-traditional touch materials, or required to operate in wet or dirty environments, such as a kitchen, bath or factory floor.

The RX Target Boards are available now through Renesas Electronics’ worldwide distributors with a recommended resale price below $30.

Renesas Electronics | www.renesas.com

Software Aids STM32 MCU System Development

STMicroelectronics has extended its STM32 software ecosystem with a Sigfox package that simplifies development and gives extra flexibility to connect Internet-of-Things (IoT) devices to long-range, low-power wireless networks. The new X-CUBE-SFOX package is ready to use with ST’s B-L072Z-LRWAN1 Discovery Kit, which is already LoRa enabled through I-CUBE-LRWAN embedded software. Developers can now work with either of these established Low-Power Wide Area Network (LPWAN) technologies on the same hardware, and create products that can use the two protocols individually or alternatively.

The Discovery Kit features the Murata CMWX1ZZABZ-091 module powered by an STM32L072 microcontroller, a sub-GHz radio transceiver SX1276 from Semtech, and is expandable via Arduino headers to add sensors or other IoT-device functions and capabilities. X-CUBE-SFOX contains a complete set of Sigfox libraries and application examples for the STM32L0, and can be ported to other microcontrollers in the STM32 family.

With over 700 STM32 variants, from ultra-low-power to high-performance lines, developers can leverage unrivaled flexibility to optimize the performance and features of IoT devices that take advantage of Sigfox services including basic connectivity, radio recognition, and GPS-free location. The software’s low memory footprint and efficient CPU utilization minimize demand for system resources, helping to lower bill-of-materials (BOM) costs and power consumption.

The X-CUBE-SFOX software can be downloaded free of charge from www.st.com/x-cube-sfox. The B-L072Z-LRWAN1 Discovery Kit is available now, priced $46.50.

STMicroelectronics | www.st.com

MIPS Development Board Giveaway

Imagination recently launched the MIPS Creator CI20 development board, which is targeted at hobbyists, makers and schools working on open source projects. The system supports Linux (currently running Debian 7, but other images are also supported) and by the end of September Android 4.4 KitKat.

MIPS Creator C120 (Source: Imagination)

MIPS Creator C120 (Source: Imagination)

Its main hardware features include:

  • Ingenic JZ4780, dual 1.2-GHz MIPS32 processor, SGX540 GPU, 32k I&D L1 cache, 512-KB L2 cache
  • IEEE754 Floating Point Unit
  • 8-GB Flash, 1-GB DDR3 memory
  • Video playback up to 1080p
  • AC97 audio, via 4-pin input/output jack and HDMI connector
  • Camera interface –ITU645 controller
  • Connectivity – 10/100 Ethernet, 802.11 b/g/n, Bluetooth 4.0
  • HDMI output up to 2K resolution
  • 2 x USB – host and OTG
  • 14-pin ETAG connector
  • 2 x UART, GPIO, SPI, I2C, ADC, expansion headers
  • Power supply

For a chance of receiving a free board, you just need to register and describe the project you want to build. If you are lucky and the company likes the sound of your proposal, you will be one of 1000 entrants to receive a free Creator CI20 development board. For more information go to the Imagination web site and fill out a request form.

Low-Power Remote-Control Transceivers

LinxThe TT Series remote-control transceiver is designed for bidirectional, long-range, remote-control applications. The module includes an optimized frequency-hopping spread spectrum (FHSS) RF transceiver and an integrated remote-control transcoder.

The FHSS is capable of reaching more than 2 miles in typical line-of-sight environments with 0-dB gain antennas. An amplified version increases the output power from 12.5 to 23.5 dBm, boosting the range to more than 8 miles in line-of-sight environments with 0-dB antennas.

The TT Series transceiver features best-in-class receive sensitivity (up to −111 dBm) and low power consumption (only 19.2 mA in receive mode and 36 mA in transmit mode at 12.5 dBm). The initial version operates in the 902-to-928-Hz frequency band for North and South America.

The transceiver is housed in a compact reflow-compatible surface-mount technology (SMT) package. It doesn’t require any external RF components except an antenna, which simplifies integration and reduces assembly costs.

Programming is not required for basic operation. The transceiver’s primary settings are hardware-selectable, which eliminates the need for an external microcontroller or other digital interface. Eight status lines can be set up in any combination of inputs and outputs to transfer button or contact states. A selectable acknowledgement indicates that the transmission was successfully received. For advanced features, a UART interface provides optional software configuration.

A simple pairing operation configures two modules to operate together. A single button press on each side causes the modules to automatically swap their 32-bit addresses and store them in nonvolatile memory. It can be configured to automatically send an acknowledgement to the transmitting unit either after receiving a command or with external circuitry when an action has taken place. An optional external processor can send two data bytes with the acknowledgement.

The TT Series transceiver module is available as part of Linx Technologies’s master development system that comes with two development boards for benchmarking and prototyping. Each board is populated with a transceiver, two remote-control development boards, and programming boards. The system also includes antennas, a daughterboard with a USB interface, demonstration software, extra modules, and connectors.

Contact Linx Technologies for pricing.

Linx Technologies