September Circuit Cellar: Sneak Preview

The September issue of Circuit Cellar magazine is out next week! This 84-page publication stitches together a fine tapestry of fascinating embedded electronics articles crafted for your reading pleasure.

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


Security Solutions for IoT
By Jeff Child
In this IoT era of connected devices, microcontrollers have begun taking on new roles and gaining new capabilities revolving around embedded security. MCUs are embedding ever-more sophisticated security features into their devices-both on their own and via partnerships with security specialists. Here, Circuit Cellar’s Editor-in-Chief, Jeff Child, looks at the latest technology and trends in MCU security.

Electromagnetic Fault Injection: A Closer Look
By Colin O’Flynn
Electromagnetic Fault Injection (EMFI) is a powerful method of inserting faults into embedded devices, but what does this give us? In this article, Colin dives into a little more detail of what sort of effects EMFI has on real devices, and expands upon a few previous articles to demonstrate some attacks on new devices.
Product Focus: IoT Gateways
By Jeff Child
IoT gateways are a smart choice to facilitate bidirectional communication between IoT field devices and the cloud. Gateways also provide local processing and storage capabilities for offline services as well as near real-time management and control of edge devices. This Product Focus section updates readers on these technology trends and provides a product gallery of representative IoT gateways.
Comparing Color Sensor ICs
By Kevin Jensen
Driven by demands from mobile phone, display and specialty lighting equipment manufacturers, the need for sophisticated and accurate chip-scale color and spectral sensors has become stronger than ever. In this article, ams’ Kevin Jensen describes the types of optical sensors and detectors. He also provides ideas on evaluating the suitability of each type for specific applications.

Mini-ITX, Pico-ITX and Nano-ITX Boards
By Jeff Child
Products based on the various small-sized versions of the ITX form factor—Mini-ITX, Pico-ITX and Nano—ITX-provide system developers with complete PC-functionality and advanced graphics. Circuit Cellar Chief Editor Jeff Child explores the latest technology trends and product developments in these three ITX architectures.
Using Small PCs in New Ways
By Wolfgang Matthes
Even simple MCU-based projects often require some sort of front panel interface. Traditionally such systems had to rely on LEDs and switches for such simple interfaces. These days however, you can buy small, inexpensive computing devices such as mini-PCs and notebook computers and adapt them to fill those interfacing roles. In this article, Wolfgang steps you through the options and issues involved in connecting such PC-based devices to an MCU-based environment.

Guitar Game Uses PIC32 MCU
By Brian Dempsey, Katarina Martucci and Liam Patterson
Guitar Hero has been an extremely popular game for decades. Many college kids today who played it when they were kids still enjoy playing it today. These three Cornell students are just such fans. Learn how they used Microchip’s microcontroller and 12-bit DAC to craft their own version that lets them play any song they wish by using MIDI files.
Offloading Intelligence
By Jeff Bachiochi
While some embedded systems do just fine with a single microcontroller, there are situations when offloading some processing into a second processing unit, such as a second MCU, offers a lot of advantages. In this article, Jeff explores this question in the context of a robotic system project that uses Arduino and an external motor driver.
Building a Portable Game Console
By Juan Joel Albrecht and Leandro Dorta Duque
32-bit MCUs can do so much these days—even providing all the needed control functionality for a gaming console. Along just those lines, learn how these three Cornell students built a portable game console that combines a Microchip PIC32 MCU embedded in a custom-designed 3D-printed case, printed circuit board and in-house gameplay graphics. The device includes a 320 x 240 TFT color display.

Variable Frequency Drive Part 2
By Brian Millier
In Part 1 Brian started to describe the process he used to convert a 3-phase motor and OEM Variable Frequency Drive (VFD) controller—salvaged from his defunct clothes washer—into a variable speed drive for his bandsaw. In this article, he completes the discussion this tim,e covering the Cypress Semi PSoC5LP SoC he used, the software design and more.
Semiconductor Fundamentals Part 1
By George Novacek
Embedded systems—or even modern electronics in general—couldn’t exist without semiconductor technology. In this new article series, George delves into the fundamentals of semiconductors. In Part 1 George examines the math, chemistry and materials science that are fundamental to semiconductors with a look at the basic structures that make them work.


Arm-Based MCU Embeds Dual ADCs and Camera Interface

Nuvoton Technology has announced a new member of its NuMicro M480 series, the M483KGCAE2A with dual ADCs and a camera interface. The M483KGCAE2A MCU is based on an Arm Cortex-M4F core with DSP instructions and FPU. The device runs up to 192 MHz and provides two independent 12-bit, 5 MSPS ADCs for simultaneous data sampling in motor control applications, a camera interface with 1-bit luminance calculation for fast image recognition and three sets of CAN Bus 2.0B interfaces for robust industrial communication. Along with the MCU, Nuvoton has released its NuMaker-M483KG development board (shown) to support development based on the M483KGCAE2A.
The two independent high-speed ADCs offer up to 24 channels with the quadrature encoder interface (QEI) and up to 16-channels of 192 MHz PWM. The M483KGCAE2A is able to obtain position feedback from mechanical devices, which realize the precise control of 3-phase servo moto. Multiple channels of ADC are also applied on multiple data sensing in power system applications including UPS and PDU. The MCU can meet IEC-60730 requirements for Class B security.

The camera interface supports CCIR656 and CCIR601 video transmission and provides hardware 1-bit luminance calculation to reduce the usage of SRAM. With the digital pattern recognition algorithm, M483KGCAE2A can recognize patterns shown in images. This makes it well suited for smart water meter, smart electricity meter or license plate number identification applications. M483KGCAE2A is equipped with three sets of CAN Bus 2.0B interfaces, the robust vehicle bus standard, connecting up to three of same types or different types of CAN devices. M483KGCAE2A works as a CAN bridge and allows a flexible network topology design.

M483KGCAE2A runs up to 192 MHz, providing 256 KB Flash memory and 128 KB SRAM. The embedded flash memory supports an eXecute-Only Memory (XOM) feature for securing the sensitive data or algorithms. The SRAM supports full or partial content retention in standby mode for reducing the power usage. When running at 192 MHz, the dynamic power consumption can be down to 130 μA/MHz; whereas in power-down mode, the power consumption of RTC with independent VBAT can be less than 500 nA.

In terms of system integrity, M483KGCAE2A support Secure Boot feature to protect the content in flash memory from malicious attack. With the Secure Boot functionality, M483KGCAE2A will verify the content of flash memory during every boot-up process. M483KGCAE2A also supports AES-256 and true random number generator for data encryption/decryption. Furthermore, M483KGCAE2A provides up to 6 tamper detection pins for system protection, 96-bit chip unique identification (UID), and 128-bit unique customer identification (UCID).

M483KGCAE2A supports 1.8 V to 3.6V  operating voltage, -40°C to 105°C operating temperature, 5 V-tolerant I/O pins and up to 3 kV ESD. Communication interfaces comprise USB full-speed OTG, 8 sets of 17 Mbps low-power UART, 1 sets of 3.4 MHz Smart Cards, 3 sets of 3.4 Mbps I²C, 2 set of 48 MB/s Quad-SPI, 3 sets of composite SPI/I²S running up to 96 Mbps or 192 kHz/16-bit I²S, 1 set of 192 kHz/32-bit I²S, and 1 set of SDIO. Integrated analog circuits include 12-bit 1 MSPS DAC and two comparators.

NuMaker-M483KG supports Arduino module and provides FreeRTOS and Arm Mbed OS with reference program including interface drivers, libraries, and sample programs. Nuvoton also provides emWin, the GUI software library for an embedded system, to easily and quickly develop and design fluent yet high quality human machine interface.

Nuvoton provides versatile hardware and software development tools, such as Nu-Link/Nu-Link-Pro programmer, which supports advanced debug function, PinConfig software for multi-function pin configuration, PinView software for monitoring pin status in real time, BSP driver and sample codes. IDE supports Keil MDK, IAR EWARM and NuEclipse (GCC), which can debug, trace and analyze your program on the development board. The new NuMicro M480 series provides several packages including QEN33, LQFP48, LQFP64 and LQFP128

Nuvoton Technology |

SEGGER Trace Probes Add Support for Hilscher NetX90 SoCs

SEGGER Microcontroller has added support for the latest Hilscher multiprotocol SoC, netX90, to its J-Trace and J-Link trace probes. Software engineers working with Hilscher’s netX90 can now enjoy the high download speeds of the J-Link and advanced features, such as breakpoints in flash memory, but also the additional features brought to the table by J-Trace-PRO, such as live code profiling and coverage.

The SEGGER J-Link / J-Trace family of debug and trace probes is tool chain independent and supports GDB, LLVM/Clang as well as most commercial tool chains. J-Trace PRO works with all currently available Cortex-M devices with ETM trace output. According to SEGGER, the increasing complexity of SoCs makes system verification even more important. The ability to log the program flow over long periods of time can catch even the most elusive bugs.

SEGGER Microcontroller|


Dual-Interface Secure MCU Targets Contactless Banking Systems

STMicroelectronics has announced the ST31P450, a dual-interface secure microcontroller designed for contactless applications in banking, identity, transportation and pay-television. It features the latest 40 nm flash process as well as enhanced RF technologies. The ST31P450 is built on the proven 32-bit Arm SecurCore SC000 secure processor and meets ISO 7816 and ISO 14443 Type A smart-card and contactless standards. It supports the full range of MIFARE libraries including MIFARE Classic, MIFARE Plus and MIFARE DESFire.

ST’s 40 nm Flash technology creates an ultra-small die for dual-interface use cases such as banking and, with security-enhancing properties, increases safety and fraud prevention. Upgraded RF performance ensures ultra-reliable wireless connections for faster, easier contactless transactions.
In addition, the ST31P450 features new low-power cryptographic engines that minimize the energy budget and ensure superior product performance at low RF-field strength while executing cryptographic operations. The ST31P450 also comes with optimized loading firmware that makes life easier for card provisioners, offering post-issuance capability.

ST31P450 secure microcontroller, and its associated cryptographic libraries, are expected to achieve Common Criteria EAL5+, as well as EMVCo and CUP (China UnionPay) certifications within the coming months.

The ST31P450, with 450KByte non-volatile memory (NVM) and 10 KB RAM on-chip, is in production now.

STMicroelectronics |


IC Solutions Rev Up for Next Gen Auto Designs

MCUs, Analog ICs and More

Automotive electronics are evolving to facilitate the shift from driver assisted vehicle controls to full autonomous driving—but that’s only part of all that’s happening. To meet a variety of design challenges, MCU and analog IC vendors are developing innovative solutions for automotive systems.

By Jeff Child, Editor-in-Chief

There’s perhaps no more vivid example of the impact of embedded electronics than the continuing advances in automotive technologies. Today, those advances are set within an era of great innovation in the industry as car makers evolve their driver assistance technologies in parallel with their autonomous vehicle solutions, while at the same time improving the performance of full electric and hybrid electric vehicles. On top of all that, car infotainment systems are moving to an entirely new level.

To meet these system design changings automotive IC makers, continue to roll out chip, development system and software solutions aimed at next-gen automotive designs. Over the past 12 months, chip vendors, primarily microcontroller (MCU) and analog IC vendors, have announced a variety of powerful System-on-Chip (SoC), MCU and analog ICs solving all kinds of problems. Leveraging their long histories of serving the automotive market, the leading MCU vendors have taken the lead facilitating driverless car systems with not just chips, but also sophisticated development platform solutions for advanced driving assistance systems (ADAS), battery management and other automotive subsystems.

Flash for Virtualization

Some of the advances in automotive electronics over the past 12 months have revolved around embedded flash solutions aimed directly at automotive system designs. In an example along those lines, in February, Renesas Electronics announced what it claims as the world’s first MCU with embedded flash that integrates a hardware-based virtualization-assisted function while maintaining the fast, real-time performance of the RH850 products.

Figure 1
The RH850/U2A MCU is equipped with up to four 400 MHz CPU cores in a dual core lock-step structure. Each CPU core integrates a hardware-based virtualization-assisted function.

This hardware-based virtualization assist technology can support up to ASIL D level of functional safety, providing greater levels of system integration. The RH850/U2A MCU (Figure 1) is the first member of Renesas’ cross-domain MCUs, a new generation of automotive-control devices, designed to address the growing need to integrate multiple applications into a single chip to realize a unified electronic control units (ECUs) for the evolving electrical-electronic architecture (E/E architecture).

Based on 28 nm process technology, the 32-bit RH850/U2A MCU builds on key functions from Renesas’ RH850/Px Series for chassis control and RH850/Fx Series for body control to deliver improved performance and implement a virtualization-assisted function to support operation in chassis/safety, body, domain control and low-end/mid-range gateway applications. The RH850/U2A MCU is equipped with up to four 400 MHz CPU cores in a dual core lock-step structure. Each CPU core integrates a hardware-based virtualization-assisted function, while maintaining the same fast real-time performance provided by the RH850. To support ASIL D, the MCU includes self-diagnostic SR-BIST (Standby-Resume BIST) functions with minimized current fluctuation rate.

The hardware-based virtualization-assisted function allows multiple software systems with varying ISO 26262 functional safety levels to operate independently without interference during high performance. It also reduces the virtualization overhead to maintain real-time execution. This enables users to integrate multiple ECU functions into a single ECU while maintaining safety, security and real-time operation requirements.
The RH850/U2A MCU is equipped with up to 16 MB of built-in flash ROM and 3.6 MB of SRAM, offering users the flexibility for future function expansion. The MCU includes security functions that support Evita Light up through Evita Full for enhanced protection against cyber-attacks, enabling the device to support safe and rapid Full No-Wait Over-the-Air (OTA) software updates as security requirements evolve.

Fail-Safe Storage

In other automotive flash technology news, in April Cypress Semiconductor announced that automotive supplier DENSO selected Cypress’ Semper fail-safe storage for its next-generation digital automotive cockpit applications with advanced graphics. Based on an embedded Arm Cortex-M0 processing core, the Semper family is purpose-built for automotive environments.

The Cypress Semper family offers high density serial NOR flash memory up to 4 Gb and leverages the company’s proprietary MirrorBit process technology. The family also features EnduraFlex architecture, which achieves greater reliability and endurance. Semper fail-safe storage devices were the first in the industry to achieve the ISO 26262 automotive functional safety standard and are ASIL-B compliant, says Cypress. According to Cypress, the Semper fail-safe storage products exceed automotive quality and functional safety requirements with ASIL-B compliance and are ready for use in ASIL-D systems. Cypress’ 512 Mb, 1 Gb and 2 Gb Semper devices are currently sampling.

Domain Controllers

For its part, STMicroelectronics (ST) also rolled out a new automotive-focused MCU offering back in February. Called the Stellar automotive MCU family, these devices support next-generation car architectures, which rely on broad “domain controllers” for areas such as the drivetrain, the chassis, and Advanced Driver Assistance Systems (ADAS). These domain controllers enable the transition toward software- and data-oriented architectures by providing data fusion from connected sensors while reducing harness complexity

Figure 2
The Stellar MCUs feature six Arm Cortex-R52 cores clocked at 400 MHz, 16 MB of Phase-Change Memory (PCM) and 8 MB of RAM, all in a BGA516 package.

Built on a 28 nm FD-SOI process, major applications for Stellar MCUs include smart control for hybrid powertrain, the broad electrification of car systems with on-board chargers, battery-management systems and DC-DC controllers, as well as smart gateways, ADAS and enhanced Vehicle Stability Controls. The MCUs feature six Arm Cortex-R52 cores clocked at 400 MHz, 16 MB of Phase-Change Memory (PCM) and 8 MB of RAM, all in a BGA516 package (Figure 2). Stellar-based control units are currently undergoing road tests with lead customers. …

Read the full article in the August 349 issue of Circuit Cellar
(Full article word count: 3207 words; Figure count: 8 Figures.)

Vendor list:

Cypress Semiconductor |
Infineon Technologies |
Maxim Integrated |
Microchip |
Momenta |
NXP Semiconductor |
Renesas Electronics America |
STMicroelectronics |
Texas Instruments |

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.

Build an RGB LED Controller

Using Parallel FET Dimming

There are a lot of fun and interesting things you can do with LEDs and the different ways to control them. In this article, Dirceu describes an alternative approach to control RGB LEDs, using the parallel FET dimming technique. He steps through his efforts to design and build an alternative lighting system based on power RGB LEDs. To control them he goes very old school and uses an 8-bit MCU and the BASIC programming language.

By Dirceu R. Rodrigues, Jr.

Nowadays, applications involving advanced processors like Arm and Espressif ESP-32 are commonplace. But I thought it would be cool to test some fun lighting sequences that are controlled by an 8-bit microcontroller (MCU) programmed using an ancient language: BASIC. Although using pulse-width modulation (PWM) to dim LEDs with MCUs is a long-established idea and there’s a plethora of such products on the market, my approach differs from others regarding the drive method used. The benefit will be a relatively shorter BOM, but is also of particular interest to embedded system designers involved with LEDs because it will be possible to experiment with alternative configurations for the control stage.

LEDs are inherently nonlinear devices. Their brightness depends primarily on the current flowing through them, even though the voltage on terminals don’t vary that much. To achieve a constant LED current, there are two approaches: linear or switched current regulation. A linear regulator is preferred in situations where the noise due to commutation would be unacceptable—or for example, in high-precision measurement equipment. When efficiency is the main concern, a switched regulator or driver usually is chosen.

A commercially available driver usually operates above 1 MHz, providing hysteretic regulation for the LED current. To implement the required dimming, a common solution is to apply a PWM signal to an enable pin of the regulator. Because the entire component is switched continuously, the delay due to the soft start function must be taken into account. The disadvantage of this mode is, therefore, the limitation at low frequencies, usually 100 Hz. Other drivers, such as the ZXLD1350 from Diodes Inc. (used here), have a similar input named ADJ, capable of accepting a PWM signal up to 1 kHz.

Figure 1
Shown here is the basic idea for the design.

As outlined in Figure 1, my application takes a different approach. Rather than applying PWM pulses to a dedicated regulator pin, these signals are used to “short-circuit” the LED. So, when a switch is closed, the corresponding LED is off. This technique—known as parallel FET dimming—does not pose a problem itself, since the driver is based on a current source. Regardless of the state of each LED, the same current always flows through the entire circuit. For an independent control of three RGB LEDs, traditionally three drivers are employed, each with its own inductor, Schottky diode and sensor resistor, as shown in Figure 2a.

Figure 2
(left) shows a traditional configuration for driving 3 LEDs. (right) shows my alternative configuration, which reduces the number of components by connecting the three LEDs in series.

My alternative configuration to reduce the number of components is to connect the three LEDs in series, each with its own switch driven by PWM (Figure 2b). Note that, in this case, the ADJ pin from the single ZXLD1350 stays floating, and the three PWM signals are moved to the gate of MOSFETs. Therefore, it is possible to control three LEDs using only one set, consisting of driver, sense resistor, flyback diode and inductor. …

Read the full article in the August 349 issue of Circuit Cellar
(Full article word count: 2287 words; Figure count: 9 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.

August Circuit Cellar: Sneak Preview

The August issue of Circuit Cellar magazine is out next week! This 84-page publication rustles up a powerful herd of compelling embedded electronics articles prepared for your reading pleasure.

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


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


MCUs for Driverless Cars
By Jeff Child
Driverless cars are steadily advancing toward becoming a mainstream phenomenon. Building toward that goal, chip vendors are evolving their driver assistance technologies into complete driver replacement solutions. These solutions make use of powerful microcontroller solutions to analyze a car’s surroundings, process the information and employ control functionality to steer cars safely. Circuit Cellar Chief Editor Jeff Child examines the MCU technology and product trends that are key to driverless vehicle evolution.

Product Focus: Small and Tiny Embedded Boards
By Jeff Child
An amazing amount of computing functionality can be squeezed on to a small form factor board these days. These small—and even tiny—board-level products meet the needs of applications where extremely low SWaP (size, weight and power) beats all other demands. This Product Focus section updates readers on this technology trend and provides a product album of representative small and tiny embedded boards.

Portable Digital Synthesizer
By T.J. Hurd and Ben Roberge
Gone are the days when even a basic music synthesizer was a bulky system requiring highly specialized design knowledge. These two Cornell students developed a portable musical synthesizer using a Microchip PIC32 MCU. The portable system performs digital audio synthesis on the fly and produces sounds that range from simple sine waves to heavily modulated waveforms.

Displays for Embedded Systems
By Jeff Child
Thanks to advances in displays and innovations in graphics ICs, embedded systems can now routinely feature sophisticated graphical user interfaces. What used to require a dedicated board-level graphics/video board, now can be integrated into a chip or just a part of a chip. Circuit Cellar Chief Editor Jeff Child dives into the latest technology trends and product developments in displays for embedded systems.

Building a Twitter Emote Robot
By Ian Kranz, Nikhil Dhawan and Sofya Calvin
Social media is so pervasive these days that it’s hard to image life without it. But digital interactions can be isolating because the physical feedback component gets lost. Using PIC32 MCU technology, these three Cornell students built an emotionally expressive robot which physically reacts to tweets in a live setting. Users can tweet to the robot’s Twitter account and receive near instant feedback as the robot shares its feelings about the tweet via physical means such as sounds, facial expressions and more.

Understanding the Role of Inference Engines in AI
By Geoff Tate, Flex Logix
Artificial Intelligence offers huge benefits for embedded systems. But implementing AI well requires making smart technology choices, especially when it comes to selected a neural inferencing engine. In this article, Flex Logix CEO Geoff Tate explains what inferencing is, how it plays into AI and how embedded system designers can make sure they are using the right solution for their AI processing.


Watt’s Up with LEDs?
By Jeff Bachiochi
When Jeff puts his mind to a technology topic, he goes in deep. In this article, he explores all aspects of LED lighting—including the history, math, science and technology of LEDs. He discusses everything from temperature issues to powering LEDs. After purchasing some LEDs, Jeff embarks on a series of tests and shares his results and insights.

Automating the Art of Toast
By Michael Xiao and Katie Bradford
The emergence of culinary robotics and automation has already begun to revolutionize the way we prepare our meals. In this article, learn how these two Cornell undergraduates designed an advanced toaster that’s able to toast any pattern—image, text or even today’s weather—onto a piece of bread. The project makes use of Microchip’s MIC32 MCU and a Raspberry Pi Zero W board.

Build an RGB LED Controller
By Dirceu R. Rodrigues Jr.
There are a lot of fun and interesting things you can do with LEDs and different ways to control them. In this article, Dirceu describes an alternative approach to control RGB LEDs using the parallel FET dimming technique. He steps through his efforts to design and build an alternative lightning system based on power RGB LEDs. To control them he goes very old school and uses an 8-bit MCU and the BASIC programming language.


Energy Monitoring Part 3
By George Novacek
This is the final installment of George’s energy monitoring article series. He discussed the solar power supply in Part 1 and the utility power data acquisition in Part 2. In Part 3, he wraps up the series by looking at the remaining modules that comprise his home energy monitoring setup, including the sensors, the natural gas monitor and the real-time clock.

The Fundamentals of Fuseology
By Robert Lacoste
Just because an electronic device is simple you shouldn’t relegate it to an afterthought in your embedded system design. Such is the case with fuses. Robert explores the fundamentals of this seemingly simple device. In this article, he dives into the history, key specifications and technology of fuses. He also steps you through an experiment to analyze the performance of fuses and shares his results.

Bluetooth Mesh (Part 4)
By Bob Japenga
In this next part of his article series on Bluetooth mesh, Bob looks at how models are defined in the Bluetooth Mesh specification and how practical it is to use them. He looks at the models defined by the Bluetooth SIG and discusses creating your own models for Bluetooth Mesh.




MCU Family Adds EtherCAT, Ethernet and CAN FD Capabilities

Texas Instruments (TI) has introduced new communications capabilities on its C2000 MCUs. C2000 F2838x 32-bit MCUs enable designers to use a single chip to implement connectivity, including EtherCAT, Ethernet and Controller Area Network with Flexible Data Rate (CAN FD), in AC servo drives and other industrial systems.

Systems with communication interfaces often require an external application-specific integrated circuit (ASIC) or dedicated host control microprocessor, which limits the flexibility of the design architecture, adds complexity and takes up space on the board. The new C2000 F2838x MCUs do not require an external ASIC, therefore reducing overall solution size and bill of materials.

By integrating three industrial communication protocols, the F2838x MCUs give designers the ability to tailor one MCU to the unique needs of each system. A key component in achieving this is a new connectivity manager, an Arm Cortex-M4-based subsystem, which offloads processing-intensive communications and optimizes connectivity. In addition to these capabilities, C2000 F2838x MCUs offer enhanced real-time control performance and higher flexibility than previous C2000 series MCUs.

For electrically isolated architectures, the new MCUs use a fast serial interface with eight receiving channels to facilitate chip-to-chip communication at up to 200 Mbps using minimal pins. Designers can build on this high level of integration in CAN FD designs and quickly increase the number of available CAN FD ports by pairing the F2838x with a TI system basis chip (SBC), such as the TCAN4550 SBC with integrated CAN FD controller and transceiver.

With a 64-bit floating-point unit and fast integer division hardware, the C28x central processing unit-based control allows for differentiated capability and high-precision designs. For servo drive applications, the fast current-loop technology processes field-oriented control in less than 500 ns to enable more precise position control.

The C2000 F2838x series also integrates a single-ended 16-bit analog-to-digital converter, which doubles the number of available channels compared to previous C2000 MCUs to minimize external components, minimize system latency and maximize control-loop accuracy. An expanded configurable logic block enables designers to customize peripherals and removes or reduces the need for a field-programmable gate array.

Pre-production samples of the C2000 TMS320F28388D are now available through the TI store in a 337 ball-grid-array package. Pricing starts at US$14.00 in 1,000-unit quantities. Developers can get started with the C2000 TMDSCNCD28388D development kit, available through the TI store for $249.

Texas Instruments |


MCUs with EtherCAT Target Industrial Applications

Renesas Electronics has introduced the RX72M Group of RX MCUs featuring an EtherCAT slave controller for industrial Ethernet communication. The new product group offers a high-performance, single-chip MCU solution with large memory capacities for industrial equipment requiring control and communication functions such as compact industrial robots, programmable logic controllers, remote I/O and industrial gateways.
According to Renesas, the use of EtherCAT in industrial Ethernet is growing fast, and is currently used on dedicated MCUs, ICs, and high-end SoC devices specialized for EtherCAT communication. The new RX72M Group achieves the superior performance of a 1396 CoreMark score at 240 MHz as measured by EEMBC Benchmarks, and it is capable of both application processing and EtherCAT communication. Combining a motor-control MCU with on-chip EtherCAT slave functions allows industrial application developers reduce their bill of materials (BOM) and support the miniaturization levels required for industrial equipment design.

The RX72M Group is the first RX MCU group to include an EtherCAT slave controller featuring the RX family’s highest SRAM capacity—1 MB of SRAM—and 4 MB of Flash memory. The large-capacity SRAM allows the MCUs to run multiple memory-intensive middleware systems, such as TCP/IP, web servers, and file systems, at high speed without the use of external memory. It also provides flexibility for the support of future functional expansions, such as OPC United Architecture (OPC UA) with no additional memory required. The on-board flash memory operates as two 2 MB banks, which enables stable operation of the end equipment, such as executing a program in one flash memory while simultaneously conducting background rewrites in the other flash memory.

Key features of the RX72M MCUs:

  • The first EtherCAT slave controller for industrial Ethernet communication in an RX MCU
  • High performance with a CoreMark benchmark score of 1396 at up to 240 MHz, and the first embedded double precision floating point unit (FPU) in an RX MCU
  • High-speed flash memory system supporting readout up to 120 MHz, creating high-performance and low-variability execution environment
  • Dedicated trigonometric function (sin, cos, arctan and hypot fucntions) accelerators and register bank save function supporting high-precision motor control implementation – a feature shared with the Renesas RX72T motor-control MCUs
  • Reliable cryptography functions such as encryption module and memory protection function in hardware to protect encryption keys – this prevents application systems from being copied without authorization and supports authentication for genuine equipment
  • Flexible package options including 176-pin LQFP and 176-pin BGA configurations as well as the first 224-pin BGA package for RX MCUs, which offers additional space saving for size-constrained designs

Samples of the RX72M Group of MCUs are available now. Renesas will begin mass production orders starting September 2019.

Renesas Electronics |

Secure Wi-Fi MCU Provides IoT Connectivity Solution

Espressif Systems has announced the release of the ESP32-S2 Secure Wi-Fi MCU, a highly integrated, low-power, 2.4 GHz Wi-Fi SoC supporting Wi-Fi HT40 and 43 GPIOs. Based on the Xtensa single-core 32-bit LX7 processor, ESP32-S2 can be clocked at up to 240 MHz.

With state-of-the-art power management and RF performance, IO capabilities and security features, ESP32-S2 is well suited for a wide variety of IoT or connectivity-based applications, including smart home and wearables. With an integrated 240 MHz Xtensa core, ESP32-S2 is sufficient for building the most demanding connected devices without requiring external MCUs.


  • CPU and Memory
    • Xtensa single-core 32-bit LX7 microcontroller
    • 7-stage pipeline
    • Clock frequency of up to 240 MHz
    • Ultra-low-power co-processor
    • 320 kB SRAM, 128 kB ROM, 16 KB RTC memory
    • External SPIRAM (128 MB total) support
    • Up to 1 GB of external flash support
    • Separate instruction and data cache
  • Connectivity
    • Wi-Fi 802.11 b/g/n
    • 1×1 transmit and receive
    • HT40 support with data rate up to 150 Mbps
    • Support for TCP/IP networking, ESP-MESH networking, TLS 1.0, 1.1 and 1.2 and other networking protocols over Wi-Fi
    • Support Time-of-Flight (TOF) measurements with normal Wi-Fi packets
  • IO Peripherals
    • 43 programmable GPIOs
    • 14 capacitive touch sensing IOs
    • Standard peripherals including SPI, I2C, I2S, UART, ADC/DAC and PWM
    • LCD (8-bit parallel RGB/8080/6800) interface and also support for 16/24-bit parallel
    • Camera interface supports 8 or 16-bit DVP image sensor, with clock frequency of up to 40 MHz
    • Full speed USB OTG support
  • Security
    • RSA-3072-based trusted application boot
    • AES256-XTS-based flash encryption to protect sensitive data at rest
    • 4096-bit eFUSE memory with 2048 bits available for application
    • Digital signature peripheral for secure storage of private keys and generation of RSA signatures
  • Power Consumption
    • ESP32-S2 supports fine resolution power control through a selection of clock frequency, duty cycle, Wi-Fi operating modes and individual power control of its internal components.
    • When Wi-Fi is enabled, the chip automatically powers on or off the RF transceiver only when needed, thereby reducing the overall power consumption of the system.
    • ULP co-processor with less than 5 uA idle mode and 24 uA at 1% duty-cycle current consumption. Improved Wi-Fi-connected and MCU-idle-mode power consumption.
  • Software
    • ESP32-S2 supports Espressif’s software development framework (ESP-IDF), which is a mature and production-ready platform, already used by millions of devices deployed in the field. Availability of common cloud connectivity agents and common product features shortens the time to market.

Engineering samples of ESP32-S2 beta are available this month (June).

Espressif Systems |

Dual-Core MCUs Blend High Performance and Enhanced Security

STMicroelectronics has announced new STM32H7 MCUs which it claims are the industry’s highest-performing Arm Cortex-M general-purpose MCUs, combining dual-core performance with power-saving features and enhanced cyber protection. The new devices leverage a 480 MHz version of the Cortex-M7, the highest performing member of Arm’s Cortex-M family, and add a 240 MHz Cortex-M4 core.

With ST’s smart architecture, efficient L1 cache, and adaptive real-time ART Accelerator, the MCUs set new speed records at 1327 DMIPS and 3224 CoreMark executing from embedded flash. ST’s Chrom-ART Accelerator provides a boost to graphics performance. To maximize energy efficiency, each core operates in its own power domain and can be turned off individually when not needed.
Developers can easily upgrade existing applications through flexible use of the two cores. They can add a sophisticated user interface to an application such as a motor drive formerly hosted on a single-core Cortex-M4 MCU by migrating legacy code to the STM32H7 Cortex-M4 with the new GUI running on the Cortex-M7. Another example is to boost application performance by offloading intensive workloads such as neural networks, checksums, DSP filtering or audio codecs.

The dual-core architecture also helps simplify code development and accelerate time to market in projects where user-interface code may be developed separately from real-time control or communication features.

STM32H7 MCUs come with pre-installed keys and native secure services including Secure Firmware Install (SFI). SFI lets customers order standard products anywhere in the world and have the encrypted firmware delivered to an external programming company without exposing unencrypted code. In addition, built-in support for Secure Boot and Secure Firmware Update (SB-SFU) protects Over the Air (OTA) feature upgrades and patches.

Compared to flash-less processors, STM32H7 MCUs deliver high performance with the extra advantage of up to 2 MB Flash and 1 MB SRAM on-chip, says ST. This helps to better handle space constraints and simplify the design of smart objects in industrial, consumer and medical applications with real-time performance or AI-processing requirements. Moreover, the Cortex-M7 level 1 cache and parallel and serial memory interfaces offer unlimited and fast access to external memory.

Additional advanced features include Error Code Correction (ECC) for all flash and RAM memory to increase safety, multiple advanced 16-bit ADCs, external ambient-temperature range up to 125°C allowing use in severe environments, an Ethernet controller and multiple FD-CAN controllers giving communication-gateway capabilities, and ST’s latest high-resolution timer for generating precision waveforms.

ST has already extended the STM32Cube ecosystem by adding STM32CubeH7 firmware modules with application source code, including graphical solutions based on TouchGFX and STemWin graphical-stack library. There are also new Evaluation, Discovery and Nucleo boards. Developers can leverage all the standard elements of the STM32Cube development environment, including the ST-MC-SUITE motor-control toolkit, STM32Cube.AI machine-learning toolkit, STM32CubeMX, STM32CubeProgrammer and certified partner solutions for STM32.

STM32H7 dual-core MCUs are entering production and samples are available now. A broad selection of packages is offered, including WLCSP. Budgetary pricing starts at $8.19 for orders of 10,000 pieces The STM32H7 single-core MCUs including the Value line are also available at a budgetary pricing starting from $3.39 for orders of 10,000 pieces.

STMicroelectronics |

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.)

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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.

Infineon Technologies to Acquire Cypress Semiconductor

Infineon Technologies and Cypress Semiconductor have announced that the companies have signed a definitive agreement under which Infineon will acquire Cypress for US $23.85 per share in cash, corresponding to an enterprise value of €9.0 billion.

With the addition of Cypress, Infineon expects to strengthen its focus on structural growth drivers and serve a broader range of applications. This will accelerate the company’s path of profitable growth of recent years. Cypress has a differentiated portfolio of microcontrollers as well as software and connectivity components that are highly complementary to Infineon’s leading power semiconductors, sensors and security solutions.

According to their joint press release, combining these technology assets will enable comprehensive advanced solutions for high-growth applications such as electric drives, battery-powered devices and power supplies. The combination of Infineon’s security expertise and Cypress’s connectivity know-how will accelerate entry into new IoT applications in the industrial and consumer segments. In automotive semiconductors, the expanded portfolio of microcontrollers and NOR flash memories will offer great potential, especially in light of their growing importance for advanced driver assistance systems and new electronic architectures in vehicles.

Under the terms of the agreement, Infineon will offer US$23.85 in cash for all outstanding shares of Cypress. This corresponds to a fully diluted enterprise value for Cypress of €9.0 billion. The offer price represents a 46 percent premium to Cypress’s unaffected 30-day volume-weighted average price during the period from 15 April to 28 May 2019, the last trading day prior to media reports regarding a potential sale of Cypress.

Cypress expects to continue its quarterly cash dividend payments until the transaction closes. This includes Cypress’s previously announced quarterly cash dividend of US$0.11 per share, payable on July 18, 2019 to holders of record of Cypress’s common stock at the close of business on June 27, 2019.

The funding of the acquisition is fully underwritten by a consortium of banks. Infineon is committed to retaining a solid investment grade rating and, consequently, Infineon intends to ultimately finance approximately 30 percent of the total transaction value with equity and the remainder with debt as well as cash on hand. The financial policy to preserve a strategic cash reserve remains in place.

The acquisition is subject to approval by Cypress’s shareholders and the relevant regulatory bodies as well as other customary conditions. The closing is expected by the end of calendar year 2019 or early 2020.

Cypress Semiconductor |
Infineon Technologies |

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.