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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

Sensor-to-Cloud Kit for Developing IoT Applications

Interested in developing cloud-connected wireless sensing products? Silicon Labs recently introduced its Thunderboard Sense Kit for developing cloud-connected devices with multiple sensing and connectivity options. The “inspiration kit” provides you with all the hardware and software needed to develop battery-powered wireless sensor nodes for the IoT.

The Thunderboard Sense Kit’s features and benefits:

  • Silicon Labs EFR32 Mighty Gecko multiprotocol wireless SoC with a 2.4-GHz chip antenna
  • ARM Cortex-M4 processor-based
  • Supports Bluetooth low energy, ZigBee, Thread, and proprietary protocols
  • Silicon Labs EFM8 Sleepy Bee microcontroller enabling fine-grained power control
  • Silicon Labs Si7021 relative humidity and temperature sensor
  • Silicon Labs Si1133 UV index and ambient light sensor
  • Bosch Sensortec BMP280 barometric pressure sensor
  • Cambridge CCS811 indoor air quality gas sensor
  • InvenSense ICM-20648 six-axis inertial sensor
  • Knowles SPV1840 MEMS microphone
  • Four high-brightness RGB LEDs
  • On-board SEGGER J-Link debugger for easy programming and debugging
  • USB Micro-B connector with virtual COM port and debug access
  • Mini Simplicity connector to access energy profiling and wireless network debugging
  • 20 breakout pins to connect to external breadboard hardware
  • CR2032 coin cell battery connector and external battery connector
  • Silicon Labs’s Simplicity Studio tools support the Thunderboard Sense

The Thunderboard Sense kit (SLTB001A) costs $36. All hardware schematics, open-source design files, mobile apps, and cloud software are included for free.

Source: Silicon Labs

Ultra-Small hSensor Platform for Wearable Apps

Maxim Integrated Products’s ultra-small hSensor Platform enables you to quickly develop wearable fitness and wellness-related prototypes. With it, you have all the necessary hardware on one PCB along with readily-accessible hardware functionality with the ARM mbed hardware development kit (HDK).Maxim health sensor

The hSensor Platform (MAXREFDES100# reference design) comprises an hSensor board that comes complete firmware with drivers, a debugger board, and a graphical user interface (GUI). The platform enables you to load algorithms for different applications.

The hSensor Platform includes the following: a MAX30003 ultra-low power, single-channel integrated biopotential AFE; a MAX30101 high-sensitivity pulse oximeter and heart-rate sensor; a MAX30205 clinical-grade temperature sensor; a MAX32620 ultra-low power ARM Cortex-M4F microcontroller optimized for wearables; a MAX14720 power management integrated circuit (PMIC); inertial sensors (three-axis accelerometer, six-axis accelerometer/gyroscope); a barometric pressure sensor; flash memory; and a Bluetooth Low Energy (BLE) radio.

The MAXREFDES100# costs $150. Hardware and firmware files are free.

Source: Maxim Integrated Products

New Ready-to-Use Wireless PCB Antennas

Pulse Electronics recently introduced three design-ready, standard, wireless printed circuit board antennas. Intended for tablets, laptops, and mobile devices, the SH0319D/E/W antenna family provides wireless signal reception ranging from dual bands to multibands covering GPS, Glonass, WLAN/dual-band WIFI, and GSM900/1800. Pulse Elect antenna

The SH0319D and SH0319E are flexible dual-band, coaxial feed antennas with a single feed point that cover 2.4- and 5-GHz frequencies. The antenna size is 8 mm × 15 mm × 1.08 mm (W x L x H) with a total size of 38 mm × 15 mm × 1.08 mm. The SW0159W is a coaxial feed multiband GPS/WLAN and GSM900/1800 antenna that covers frequency ranges of 1.5/2.4 GHz, 5 GHz, and 900/1,800 MHz. It has dual feed points. The antenna size is 70 mm × 10 mm × 1 mm with a total size of 70 mm × 15 mm × 1 mm.


Source: Pulse Electronics

Human Vision Image-Sensing System Provides 10× Faster Recognition

Mouser Electronics is now offering Omron Electronic Components’s fully integrated B5T HVC-P2 face detection sensor modules. The Human Vision Component (HVC) plug-in modules are based on Omron’s OKAO Vision Image Sensing Technology, which is used to quickly and accurately detect human bodies and faces.Omron Image Sensors

Well suite for a variety of IoT applications, the face detection sensor modules comprise a camera and a separate main board that are connected via a flexible flat cable, which enables you to install it on the edge of a flat display unit. The boards feature UART and USB interfaces to control the module and send the data output (as no image output, 160 × 120 pixels, or 320 × 240 pixels) to an external system.

Available in both wide-angle (90-degree lens) and long-distance lenses (50-degree lens), the B5T HVC-P2 modules can detect a human body up to four times per second. The long-distance module can detect and presume attributes (e.g., gender and age, sight line, and facial expression) from a maximum distance of 3 m. The wide-angle module can cover an area 100 cm × 75 cm from a distance of 50 cm.

Source: Mouser Electronics

Flowcode 7 (Part 2): Displays in Flowcode (Sponsor: Matrix)

In the first part of this series, you were introduced to Flowcode 7, a flowchart-driven electronic IDE that enables you to produce hex code for more than 1,300 different microcontrollers, including PIC8, PIC16, PIC32, AVR, Arduino, and ARM. In the second free article in this series, embedded engineer Ben Rowland gets you working with displays in Flowcode. He covers: communicating with displays, code and display porting, a bitmap drawer component, and more.

A maze generation algorithm being tested using a graphical LCD and the Flowcode simulation.

A maze generation algorithm being tested using a graphical LCD and the Flowcode simulation.

Want a Free Trial and/or Buy Flowcode 7? Download Now

Flowcode is an IDE for electronic and electromechanical system development. Pro engineers, electronics enthusiasts, and academics can use Flowcode to develop systems for control and measurement based on microcontrollers or on rugged industrial interfaces using Windows-compatible personal computers. Visit www.flowcode.co.uk/circuitcellar to learn about Flowcode 7. You can access a free version, or you can purchase advanced features and professional Flowcode licenses through the modular licensing system. If you make a purchase through that page, Circuit Cellar will receive a commission.

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New ARM Technologies for Secure IoT Applications

ARM recently released a new product suite of technologies for designers of secure Internet of Things (IoT) applications.The product suite comprises procesors, cloud-based services platform, radio technology, subsystems, and comprehensive security.

Cortex-M Processors Integrated with TrustZone

The ARM Cortex-M23 and Cortex-M33 are built on the ARMv8-M architecture featuring ARM TrustZone security and digital signal processing. TrustZone CryptoCell-312 offers security features that protect the authenticity, integrity, and confidentiality of code and data. The Cortex-M23 is a compact, energy-efficient processor well-suited for constrained embedded applications. The highly configurable Cortex-M33 features a variety options including a coprocessor interface, digital signal processing and floating-point computation. Both new Cortex-M processors are backwards compatible with ARMv6-M and ARMv7-M architectures.

ARM System IP Optimized for Cortex-M Processors

ARM CoreLink SIE-200 is already licensed by ARM silicon partners and provides the interconnects and controllers that extend TrustZone to the system. The ARM CoreLink SSE-200 IoT subsystem reduces time to market by integrating Cortex-M33, CryptoCell, and Cordio radio along with software drivers, secure libraries, protocol stack, and the mbed OS.

IoT Connectivity

Connectivity is enhanced by next-generation ARM Cordio radio IP with Bluetooth 5 and 802.15.4-based standards ZigBee and Thread. Developers can choose from a standard radio implementation across a range of process nodes from multiple foundries. The Cordio architecture supports ARM and third-party RF.

Cloud-Based SaaS for Secure IoT Device Management

The ARM mbed IoT Device Platform has been expanded to include mbed Cloud, a new standards and cloud-based SaaS solution for secure IoT device management. Through mbed Cloud, OEMs can:

Simplify connection, provisioning, updating and securing of devices across complex networks
Enable faster scaling, productivity and time to market, allowing developers to use any device on any cloud
Enhance device-side capabilities with mbed OS 5, supported by a global community of 200,000 developers and more than 1 million device builds per month.

Implementation with IoT POP on TSMC 40ULP

Designers can quicken the development of SoCs featuring the latest Cortex-M processors with Artisan IoT POP IP now available for TSMC 40ULP process technology. ARM Artisan IoT POP IP enables low-power designs and optimizing for IoT applications.

Source: ARM 

The Future of Ultra-Low Power Signal Processing

One of my favorite quotes comes from the IEEE Signal Processing magazine in 2010. They attempted to answer the question: What does ultra-low power consumption mean? And they came to the conclusion that it is where the “power source lasts longer than the useful life of the product.”[1] It’s a great answer because it’s scalable. It applies equally to signal processing circuitry inside an embedded IoT device that can never be accessed or recharged and to signal processing inside a car where the petrol for the engine dominates the operating lifetime, not the signal processing power. It also describes exactly what a lot of science fiction has always envisioned: no changing or recharging of batteries, which people forget to do or never have enough batteries for. Rather, we have devices that simply always work.Figure 1

My research focuses on healthcare applications and creating “wearable algorithms”—that is, signal processing implementations that fit within the very small power budgets available in wearable devices. Historically, this focused on data reduction to save power. It’s well known that wireless data transmission is very power intensive. By using some power to reduce the amount of data that has to be sent, it’s possible to save lots of power in the wireless transmission stage and so to increase the overall battery lifetime.

This argument has been known for a long time. There are papers dating back to at least the 1990s based on it. It’s also readily achievable. Inevitably, it depends on the precise situation, but we showed in 2014 that the power consumption of a wireless sensor node could be brought down to the level of a node without a wireless transmitter (one that uses local flash memory) using easily available, easy-to-use, off-the-shelf-devices.[2]

This essay appears in Circuit Cellar 316, November 2016. Subscribe to Circuit Cellar to read project articles, essays, interviews, and tutorials every month!

Today, there are many additional benefits that are being enabled by the emerging use of ultra-low power signal processing embedded in the wearable itself, and these new applications are driving the research challenges: increased device functionality; minimized system latency; reliable, robust operation over unreliable wireless links; reduction in the amount of data to be analyzed offline; better quality recordings (e.g., with motion artifact removal to prevent signal saturations); new closed-loop recording—stimulation devices; and real-time data redaction for privacy, ensuring personal data never leaves the wearable.

It’s these last two that are the focus for my research now. They’re really important for enabling new “bioelectronic” medical devices which apply electrical stimulation as an alternative to classical pharmacological treatments. These “bioelectronics” will be fully data-driven, analyzing physiological measurements in real-time and using this to decide when to optimally trigger an intervention. Doing such as analysis on a wearable sensor node though requires ultra-low power signal processing that has all of the feature extraction and signal classification operating within a power budget of a few 100 µW or less.

To achieve this, most works do not use any specific software platform. Instead they achieve very low-power consumption by using only dedicated and highly customized hardware circuits. While there are many different approaches to realizing low-power fully custom electronics, for the hardware, the design trends are reasonably established: very low supply voltages, typically in the 0.5 to 1 V range; highly simplified circuit architectures, where a small reduction in processing accuracy leads to substantial power savings; and the use of extensive analogue processing in the very lowest power consumption circuits.[3]

Less well established are the signal processing functions for ultra-low power. Focusing on feature extractions, our 2015 review highlighted that the majority (more than half) of wearable algorithms created to date are based upon frequency information, with wavelet transforms being particularly popular.[4] This indicates a potential over-reliance on time–frequency decompositions as the best algorithmic starting points. It seems unlikely that time–frequency decompositions would provide the best, or even suitable, feature extraction across all signal types and all potential applications. There is a clear opportunity for creating wearable algorithms that are based on other feature extraction methods, such as the fractal dimension or Empirical Mode Decomposition.

Investigating this requires studying the three-way trade-off between algorithm performance (e.g., correct detections), algorithm cost (e.g., false detections), and power consumption. We know how to design signal processing algorithms, and we know how to design ultra-low power circuitry. However, combining the two opens many new degrees of freedom in the design space, and there are many opportunities and work to do in mapping feature extractions and classifiers into sub-1-V power supply dedicated hardware.

[1] G. Frantz, et al, “Ultra-low power signal processing,” IEEE Signal Processing Magazine, vol. 27, no. 2, 2010.
[2] S. A. Imtiaz, A. J. Casson, and E. Rodriguez-Villegas, “Compression in Wearable Sensor Nodes,” IEEE Transactions on Biomedical Engineering, vol. 61, no. 4, 2014.
[3] A. J. Casson, et al, “Wearable Algorithms,” in E. Sazonov and M. R. Neuman (eds.), Wearable Sensors, Elsevier, 2014.
[4] A. J. Casson, “Opportunities and Challenges for Ultra Low Power Signal Processing in Wearable Healthcare,” 23rd European Signal Processing Conference, Nice, 2015.

Alex Casson is a lecturer in the Sensing, Imaging, and Signal Processing Department at the University of Manchester. His research focuses on creating next-generation human body sensors, developing both the required hardware and software. Dr. Casson earned an undergraduate degree at the University of Oxford and a PhD from Imperial College London.

New Embedded Solution for Debugging FPGAs

Exostiv Labs recently announced that its EXOSTIV solution for Intel FPGAs will be available in December 2016. Providing up to 200,000 times more visibility on an FPGA than other solutions, EXOSTIV enables the debugging and verification of FPGA board prototypes at speed of operation. It provides extended visibility on internal nodes over long periods of time with minimal impact on the FPGA resources. Thus, you can discover issues related to complex interactions between numerous IPs when simulation is impracticable.

EXOSTIV for Intel FPGAs will be released in December 2016 with support for Arria 10 devices first. Pricing starts at $5,100.

Source: Exostiv Labs 

Wi-Fi-Enabled E-Paper

Pervasive Displays recently released a low-power, Wi-Fi-enabled e-paper display (EPD). The SimpleLink Wi-Fi CC3200 wireless MCU-based EPD is compatible with any of five different EPD panel sizes. You can control it wirelessly over the Internet with the MQTT protocol.pervasive WiFi

The low-power design comprises a SimpleLink Wi-Fi CC3200 LaunchPad development kit featuring n ARM Cortex-M4-based wireless microcontroller. The EPD sits on a BoosterPack-compatible plug-in board, which enables you to choose one of five e-paper display sizes from 1.44″ to 2.7″. An SPI enables communication between the microcontroller and the display.

Operating in the range of 2.3 to 3.6 VDC, the efficient EPD display can be updated via either an attached network or the Internet with a cloud-based application. Application firmware running permits control of the displayed image either via an embedded HTTP page or an MQTT client. With the HTTP client, you can choose from text and image format templates to be displayed and configured according to your needs.

The SimpleLink Wi-Fi CC3200 SDK contains an MQTT example along with the Pervasive Displays driver. The microcontroller uses a FreeRTOS environment with a thread for the SimpleLink functions and a thread for the display communication.

Source: Pervasive Displays


eSOL RTOS & Debugger Support for Software Development

Imperas Software recently announced its support for eSOL’s eMCOS RTOS and eBinder debugger. The partnership is intended to accelerate embedded software development, debugging, and testing.

The Imperas Extendable Platform Kit (EPK) features a Renesas RH850F1H device and it runs the eSOL eMCOS real time operating system. Imperas simulators can use the debugger from the eSOL IDE, eBinder, for efficient software debugging and testing.

Source: eSOL

Low Latency 48-Port FPGA Networking Appliance

BittWare and LDA Technologies are collaborating on a low-latency 48-port FPGA networking appliance. The LDA e4 is a 10/25-Gbps-capable FPGA board enclosure that repurposes the serial links on BittWare’s PCIe FPGA boards into high-speed Ethernet ports.

Features, benefits, and specs:

  • 6″ FPGA-to-port trace lengths
  • Layer 1 replication, support for various CPUs and operating systems
  • A high-accuracy clock source enables accurate timestamping
  • Enables out-of-band management and a zero configuration option

Source: BittWare

Conductive Paint: An Interview with Bare Conductive

Back in 2009, a small team of students at the Royal College of Art in London, England, began experimenting with a nontoxic conductive paint. That work laid the foundation for their company Bare Conductive, which inspires artists and engineers to take on innovative projects that involve painting circuits. Circuit Cellar travels to Commercial Street in London and interviews Stefan Dzisiewski-Smith and Isabel Lizardi, two members of Bare Conductive.conductive paint

“There are many conductive paints on the market, and people are using it for various applications,” explained Isabel Lixardi, one of Bare Conductive’s founders. “Many of these paints are ferro-based, making the applications specific and you often have to use protective clothing and gloves to work with it. Our goal was to develop a carbon and water based paint that was non-toxic and easy to use for anybody: from young kids to artists and engineers. We also see interesting examples in businesses.”

New Tricolor E-Paper Displays

Pervasive Displays recently launched the first two products in its Spectra family of three-pigment black, white and red e-paper displays (EPDs). Intended for a wide variety of applications (e.g., electronic shelf labels and smart cards), the thin Spectra EPD is an active matrix TFT glass substrate display with a 180° viewing angle.Pervasive-Spectra

The 2.87″ E2287ES051 module offers a 296 × 128 resolution and 112 dpi pixel density. The 4.2″ E2417ES053 model has 400 × 300 resolution and 120 dpi high-pixel density. Both anti-glare displays have a vertical pixel arrangement.

Spectra EPD features an SPI interface and a fine-tuned embedded waveform for superior optical performance. You can customize the embedded waveform for your specific applications. The bistable Spectra EPD panels require little power to update; they don’t use power to maintain an image. The displays can operate over an ambient temperature range of 0° to 40°. Breakage detection is supported.

Source: Pervasive Displays

New “Easy Integration” Antenna for Small Devices

Antenova recently added the Inca (part no SRFI028) antenna to its flexiiANT FPC family. Designed for small devices in the 433-MHz ISM band, the compact (101 mm × 20 mm × 0.15 mm), lightweight (0.5 g) antenna is well-suited for small electronic devices and Internet of Things (IoT) applications in the 433-MHz band, such as robot control, home automation, and medical devices.Antenova Inca

Features and specs include: flexibility, so you can fold the antenna or place it flat in your design; an I-PEX connector in a choice of three cable lengths (100, 150, or 200 mm); and peel-back, self-adhesive backing.

Inca (SRFI028) is supplied in packs of 100 for convenience and quick delivery. Samples of this antenna are now available.

Source: Antenova