Motor Drivers Provide Solution for Low- to Mid-Power Applications

STMicroelectronics has released the STSPIN830 and STSPIN840 single-chip drivers that simplify the design of low-to-mid-power motor controls in the 7 V to 45 V range.  The devices contain flexible control logic and low-RDS(ON) power switches for industrial applications, medical technology, and home appliances.
The STSPIN830 for driving 3-phase brushless DC motors has a mode-setting pin that lets users control the three half bridges of the integrated power stage with direct U, V, and W pulse-width modulated (PWM) inputs, or by applying signals to each gate individually for higher control flexibility. A dedicated sense pin for each inverter leg simplifies setting up three-shunt or single-shunt current sensing for Field-Oriented Control (FOC).

The STSPIN840 can drive two brushed DC motors or one larger motor leveraging ST’s well- known, market-proven paralleling concept, which allows the integrated full bridges to be configured as two separate bridges or as a single bridge using the two sets of MOSFETs in parallel for lower RDS(ON) and higher current rating.

Both drivers contain rich features, including PWM current-control circuitry with adjustable off-time, a convenient standby pin for power saving, and protection circuitry including non-dissipative overcurrent protection, short-circuit protection, undervoltage lockout, thermal shutdown, and interlocking to help create robust and reliable drives.

The integrated power stage of each device features ST-proprietary MOSFETs with low RDS(ON) of only 500 mΩ to combine high efficiency with economy. The option to use the output bridges individually or connected in parallel, in the STSPIN840, helps trim the BOM for multi-motor applications.

With their high feature integration and flexibility, the drivers enable more compact and cost-effective controls for industrial, robotic, medical, building-automation, and office-equipment applications. The STSPIN830 is ideal for factory-automation end-points, home appliances, small pumps, and fans for computer or general-purpose cooling. The STSPIN840 targets ATM and money-handling machines, multi-axis stage-lighting mechanisms, thermal printers, textile or sewing machines, and vending machines.

The STSPIN830 and STSPIN840 are both in production now, as 4 mm x 4 mm QFN devices. Pricing for both starts from $1.25 for orders of 1,000 pieces.

Two STM32 Nucleo expansion boards are provided to facilitate product evaluation and build functional prototypes using the STM32 Open Development Environment: X-NUCLEO-IHM16M1 for the STSPIN830 and X-NUCLEO-IHM15A1 for the STSPIN840, both priced at $16.

STMicroelectronics | www.st.com

September Circuit Cellar: Sneak Preview

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MOTORS, MOTION CONTROL AND MORE

Motion Control for Robotics
Motion control technology for robotic systems continues to advance, as chip- and board-level solutions evolve to meet new demands. These involve a blending of precise analog technologies to control position, torque and speed with signal processing to enable accurate, real-time motor control. Here, Circuit Cellar’s Editor-in-Chief, Jeff Child, looks the latest technology and product advances in motion control for robotics.

Electronic Speed Control (Part 3)
Radio-controlled drones are one among many applications that depend on the use of an Electronic Speed Controller (ESC) as part of its motor control design. After observing the operation of a number of ESC modules, in this part Jeff Bachiochi focuses in more closely on the interaction of the ESC with the BLDC motor.

BUILDING CONNECTED SYSTEMS

Product Focus: IoT Gateways
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.

Wireless Weather Station
Integrating wireless technologies into embedded systems has become much easier these days. In this project article, Raul Alvarez Torrico describes his home-made wireless weather station that monitors ambient temperature, relative humidity, wind speed and wind direction, using Arduino and a pair of cheap Amplitude Shift Keying (ASK) radio modules.

FOCUS ON ANALOG AND POWER TECHNOLOGY

Frequency Modulated DDS
Prompted by a reader’s query, Ed became aware that you can no longer get crystal oscillator modules tuned to specific frequencies. With that in mind, Ed set out to build a “Channel Element” replacement around a Teensy 3.6 board and a DDS module. In this article, Ed Nisley explains how the Teensy’s 32-bit datapath and 180 MHz CPU clock affect the DDS frequency calculations. He then explores some detailed timings.

Power Supplies / Batteries
Sometimes power decisions are left as an afterthought in system designs. But your choice of power supply or battery strategy can have a major impact on your system’s capabilities. Circuit Cellar’s Editor-in-Chief, Jeff Child, dives into the latest technology trends and product developments in power supplies and batteries.

Murphy’s Laws in the DSP World (Part 3)
Unpredictable issues crop up when you move from the real world of analog signals and enter the world of digital signal processing (DSP). In Part 3 of this article series, Mike Smith and Mai Tanaka focuses on strategies for how to—or how to try to—avoid Murphy’s Laws when doing DSP.

SYSTEM DESIGN ISSUES IN VIDEO AND IMAGING

Virtual Emulation for Drones
Drone system designers are integrating high-definition video and other features into their SoCs. Verifying the video capture circuitry, data collection components and UHD-4K streaming video capabilities found in drones is not trivial. In his article, Mentor’s Richard Pugh explains why drone verification is a natural fit for hardware emulation because emulation is very efficient at handling large amounts of streamed data.

LIDAR 3D Imaging on a Budget
Demand is on the rise for 3D image data for use in a variety of applications, from autonomous cars to military base security. That has spurred research into high precision LIDAR systems capable of creating extremely clear 3D images to meet this demand. Learn how Cornell student Chris Graef leveraged inexpensive LIDAR sensors to build a 3D imaging system all within a budget of around $200.

AND MORE FROM OUR EXPERT COLUMNISTS

Velocity and Speed Sensors
Automatic systems require real-life physical attributes to be measured and converted to electrical quantities ready for electronic processing. Velocity is one such attribute. In this article, George Novacek steps through the math, science and technology behind measuring velocity and the sensors used for such measurements.

Recreating the LPC Code Protection Bypass
Microcontroller fuse bits are used to protect code from being read out. How well do they work in practice? Some of them have been recently broken. In this article Colin O’Flynn takes you through the details of such an attack to help you understand the realistic threat model.

August Circuit Cellar: Sneak Preview

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FPGAs REDEFINE THE DEFINITION OF “SYSTEM”

FPGA System Design
Long gone now are the days when FPGAs were thought of as simple programmable circuitry for interfacing and glue logic. Today, FPGAs are powerful system chips with on-chip processors, signal processing functionality and rich offerings or high-speed connectivity. Here, Circuit Cellar’s Editor-in-Chief, Jeff Child, looks at the latest technology and trends in FPGA system design.

Managing FPGA Design Complexity
Modern FPGAs can contain millions of logic gates and thousands of embedded DSP processors allowing FPGA hardware designers to create extremely sophisticated and complex application-specific hardware functions. In this article, Pentek’s Bob Sgandurra explores how today’s FPGA technology has revamped the roles of both hardware and software engineers as well as how dealing with on-chip IP adds new layers of complexity.

HIGH-INTEGRATION AT THE CHIP-
AND BOARD-LEVEL

Product Focus: Small and Tiny Embedded Boards
An amazing amount of computing functionality can be squeezed on to a small form factor board these days. These company—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.

Microcontrollers and Processors
Today’s crop of microcontrollers and embedded processors provide a rich continuum of features, functions and capabilities. It’s hard to tell anymore where the dividing line is, especially when a lot of them use the same CPU cores. Circuit Cellar’s Editor-in-Chief, Jeff Child, delves into the technology and product trends of MCUs and embedded processors.

CAN’T STOP THE SIGNAL

Murphy’s Laws in the DSP World (Part 2)
Many unexpected issues come into play when you move from the real world of analog signals and enter the world of digital signal processing (DSP). Part 2 of this article series by Michael Smith, Mai Tanaka and Ehsan Shahrabi Farahani charges forward introducing “Murphy’s Laws of DSP” #7, #8 and #9 and looks at the spectral analysis of DSP signals.

Signature Analyzer Uses NXP MCU
Doing a signature analysis of a signal used to require an oscilloscope to display your results. In this article, Brian Millier shows how you can build a free-standing tester that uses mostly just the internal peripherals of an NXP ARM microcontroller. He described how the tester operates and how he implemented it using a Teensy 3.5 development module and an intelligent 4.3-inch TFT touch-screen display.

Pitfalls of Filtering Pulsed Signals
Filtering pulsed signals can be a tricky prospect. Using a recent customer implementation as an example, Robert Lacoste highlights various alternative approaches and describes the key concepts involved. Simulation results are provided to help readers understand what’s going on.

PROJECT-BASED STORIES WITH ALL THE DETAILS

Electronic Speed Control (Part 2)
In Part 1, Jeff Bachiochi discussed the mechanical differences between DC brushed and brushless DC (BLDC) motors. This time he dives into basics of an Electronic Speed Controller’s operations and its circuitry. And all this is illustrated via his ESC-based project that uses a Microchip PIC MCU.

Build an Audio Response Light Display
Light shows have been a part of entertainment situations seemingly forever, but the technology has evolved over time. These light shows have their origin in the primitive “light organs” of the 1960s in which each spectral band had its own color that pulsed in intensity with audio amplitudes within its range of frequencies. In this article, Devlin Gualtieri discusses his circuit design that implements a light organ using today’s IC and LED technologies.

AND MORE FROM OUR EXPERT COLUMNISTS

Internet of Things Security (Part 4)
In this next part of his article series on IoT security, Bob Japenga looks at how checklists and the common criteria framework can help us create more secure IoT devices. He covers how to create a list of security assets and to establish threat checklists that identify all the threats to your security assets.

Thermoelectric Cooling (Part 2)
In Part 1 George Novacek described how he built a test chamber using some electronics combined with components salvaged from his thermoelectric water cooler. To confirm his test results, he purchased another thermoelectric cooler and repeated the tests. In Part 2 he covers the results of these tests along with some theoretical performance calculations.

BLDC Fan Current

Motors and Measurements

Today’s small fans and blowers depend on brushless DC (BLDC) motor technology for their operation. Here, Ed explains how these seemingly simple devices are actually quite complex when you measure them in action.

By Ed Nisley

The 3D printer Cambrian Explosion unleashed both the stepper motors you’ve seen in previous articles and the cooling fans required to compensate for their abuse. As fans became small and cheap, Moore’s Law converted them from simple DC motors into electronic devices, simultaneously invalidating the assumptions people (including myself) have about their proper use.

In this article, I’ll make some measurements on the motor inside a tangential blower and explore how the data relates to the basic physics of moving air.

Brushless DC Motors

Electric motors, regardless of their power source, produce motion by opposing the magnetic field in their rotor against the field in their stator. Small motors generally produce one magnetic field with permanent magnets, which means the other magnetic field must change with time in order to keep the rotor spinning. Motors powered from an AC source, typically the power line for simple motors, have inherently time-varying currents, but motors connected to a DC source require a switching mechanism, called a commutator, to produce the proper current waveforms.

Mechanical commutators date back to the earliest days of motor technology, when motors passed DC power supply current through graphite blocks sliding over copper bars to switch the rotor winding currents without external hardware. For example, the commutator in the lead photo switches the rotor current of a 1065 horsepower marine propulsion motor installed on Fireboat Harvey in 1930, where it’s still in use after nine decades.

Fireboat Harvey’s motors produce the stator field using DC electromagnets powered by steam-driven exciter generators. Small DC motors now use high-flux, rare-earth magnets and no longer need boilers or exhaust stacks.

Although graphite sliding on copper sufficed for the first century of DC motors, many DC motors now use electronic commutation, with semiconductor power switches driven by surprisingly complex logic embedded in a dedicated controller. These motors seem “inside out” compared to older designs, with permanent magnets producing a fixed rotor field and the controller producing a time-varying stator field. The relentless application of Moore’s Law put the controller and power switches on a single PCB hidden inside the motor case, out of sight and out of mind.

Because semiconductor switches eliminated the need for carbon brushes, the motors became known as Brushless DC motors. Externally, they operate from a DC supply and, with only two wires, don’t seem particularly complicated. Internally, their wiring and currents resemble multi-phase AC induction motors using pseudo-sinusoidal stator voltage waveforms. As a result, they have entirely different power supply requirements.

The magnetic field in the rotor of a mechanically commutated motor has a fixed relationship to the stator field. As the rotor turns, its magnetic field remains stationary with respect to the stator as the brushes activate successive sections of the rotor winding to produce essentially constant torque against the stator field. Electronically commutated motors must sense the rotor position to produce stator currents with the proper torque against the moving rotor field. As you’ll see, the motor controller can use the back EMF generated by the spinning rotor to determine its position, thereby eliminating any additional components.

Figure 1
The blower motor current varies linearly with its supply voltage, so the power consumption varies as the square of the voltage. The motor speed depends on the balance between torque and load.

I originally thought Brushless DC (BLDC) motors operated much like steppers, with the controller regulating the winding current, but the switches actually regulate the voltage applied to the windings, with the current determined by the difference between the applied voltage and the back EMF due to the rotor speed. The difference between current drive and voltage drive means steppers and BLDC motors have completely different behaviors.

Constant Voltage Operation

The orange trace along the bottom of Figure 1 shows the current drawn by the 24 V tangential blower shown in Figure 2, without the anemometer on its outlet, for supply voltages between 2.3 V and 26 V. The BLDC motor controller shapes the DC supply voltage into AC waveforms, the winding current varies linearly with the applied voltage and, perhaps surprisingly, the blower looks like a 100 Ω resistor.

Figure 2
An anemometer measures the blower’s outlet air speed and a square of retroreflective tape on the rotor provides a target for the laser tachometer. If you are doing this in a lab, you should build a larger duct with a flow straightener and airtight joints.

The blower’s power dissipation therefore varies as the square of the supply voltage, as shown by the calculated dots in the purple curve. In fact, the quadratic equation fitting the data has 0.00 coefficients for both the linear and constant terms, so it’s as good as simple measurements can get.

As you saw in March (Circuit Cellar #332) and May (Circuit Cellar #334), a stepper motor driven by a microstepping controller has a constant winding current and operates at a constant power. Increasing the supply voltage increases the rate of current change but, because the controller applies the increasing voltage with a lower duty cycle, it doesn’t directly increase power dissipation. …

Read the full article in the July 336 issue of Circuit Cellar

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TECHNOLOGIES FOR THE INTERNET-OF-THINGS

Wireless Standards and Solutions for IoT  
One of the critical enabling technologies making the Internet-of-Things possible is the set of well-established wireless standards that allow movement of data to and from low-power edge devices. Here, Circuit Cellar’s Editor-in-Chief, Jeff Child, looks at key wireless standards and solutions playing a role in IoT.

Product Focus: IoT Device Modules
The rapidly growing IoT phenomenon is driving demand for highly integrated modules designed to interface with IoT devices. This Product Focus section updates readers on this technology trend and provides a product album of representative IoT interface modules.

TOOLS AND TECHNIQUES AT THE DESIGN PHASE

EMC Analysis During PCB Layout
If your electronic product design fails EMC compliance testing for its target market, that product can’t be sold. That’s why EMC analysis is such an important step. In his article, Mentor Graphics’ Craig Armenti shows how implementing EMC analysis during the design phase provides an opportunity to avoid failing EMC compliance testing after fabrication.

Extreme Low-Power Design
Wearable consumer devices, IoT sensors and handheld systems are just a few of the applications that strive for extreme low-power consumption. Beyond just battery-driven designs, today’s system developers want no-battery solutions and even energy harvesting. Circuit Cellar’s Editor-in-Chief, Jeff Child, dives into the latest technology trends and product developments in extreme low power.

Op Amp Design Techniques
Op amps can play useful roles in circuit designs linking the real analog world to microcontrollers. Stuart Ball shares techniques for using op amps and related devices like comparators to optimize your designs and improve precision.

Wire Wrapping Revisited
Wire wrapping may seem old fashioned, but this tried and true technology can solve some tricky problems that arise when you try to interconnect different kinds of modules like Arduino, Raspberry Pi and so on. Wolfgang Matthes steps through how to best employ wire wrapping for this purpose and provides application examples.

DEEP DIVES ON MOTOR CONTROL AND MONITORING

BLDC Fan Current
Today’s small fans and blowers depend on brushless DC (BLDC) motor technology for their operation. In this article, Ed Nisley explains how these seemingly simple devices are actually quite complex when you measure them in action. He makes some measurements on the motor inside a tangential blower and explores how the data relates to the basic physics of moving air.

Electronic Speed Control (Part 1)
An Electronic Speed Controller (ESC) is an important device in motor control designs, especially in the world of radio-controlled (RC) model vehicles. In Part 1, Jeff Bachiochi lays the groundwork by discussing the evolution of brushed motors to brushless motors. He then explores in detail the role ESC devices play in RC vehicle motors.

MCU-Based Motor Condition Monitoring
Thanks to advances in microcontrollers and sensors, it’s now possible to electronically monitor aspects of a motor’s condition, like current consumption, pressure and vibration. In this article, Texas Instrument’s Amit Ashara steps through how to best use the resources on an MCU to preform condition monitoring on motors. He looks at the signal chain, connectivity issues and A-D conversion.

AND MORE FROM OUR EXPERT COLUMNISTS

Verifying Code Readout Protection Claims
How do you verify the security of microcontrollers? MCU manufacturers often make big claims, but sometimes it is in your best interest to verify them yourself. In this article, Colin O’Flynn discusses a few threats against code readout and looks at verifying some of those claimed levels.

Thermoelectric Cooling (Part 1)
When his thermoelectric water color died prematurely, George Novacek was curious whether it was a defective unit or a design problem. With that in mind, he decided to create a test chamber using some electronics combined with components salvaged from the water cooler. His tests provide some interesting insights into thermoelectric cooling.

 

March Circuit Cellar: Sneak Preview

The March issue of Circuit Cellar magazine is coming soon. And we’ve got a healthy serving of embedded electronics articles for you. Here’s a sneak peak.

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TECHNOLOGY FOR THE INTERNET-OF-THINGS

IoT: From Device to Gateway
The Internet of Things (IoT) is one of the most dynamic areas of embedded systems design today. This feature focuses on the technologies and products from edge IoT devices up to IoT gateways. Circuit Cellar Chief Editor Jeff Child examines the wireless technologies, sensors, edge devices and IoT gateway technologies at the center of this phenomenon.

Texting and IoT Embedded Devices
Texting has become a huge part of our daily lives. But can texting be leveraged for use in IoT Wi-Fi devices? Jeff Bachiochi lays the groundwork for describing a project that will involve texting. In this part, he gets into out the details for getting started with a look at Espressif System’s ESP8266EX SoC.

Exploring the ESP32’s Peripheral Blocks
What makes an embedded processor suitable as an IoT or home control device? Wi-Fi support is just part of the picture. Brian Millier has done some Wi-Fi projects using the ESP32, so here he shares his insights about the peripherals on the ESP32 and why they’re so powerful.

MICROCONTROLLERS HERE, THERE & EVERYWHERE

Designing a Home Cleaning Robot (Part 4)
In this final part of his four-part article series about building a home cleaning robot, Nishant Mittal discusses the firmware part of the system and gets into the system’s actual operation. The robot is based on Cypress Semiconductor’s PSoC microcontroller.

Apartment Entry System Uses PIC32
Learn how a Cornell undergraduate built a system that enables an apartment resident to enter when keys are lost or to grant access to a guest when there’s no one home. The system consists of a microphone connected to a Microchip PIC32 MCU that controls a push solenoid to actuate the unlock button.

Posture Corrector Leverages Bluetooth
Learn how these Cornell students built a posture corrector that helps remind you to sit up straight. Using vibration and visual cues, this wearable device is paired with a phone app and makes use of Bluetooth and Microchip PIC32 technology.

INTERACTING WITH THE ANALOG WORLD

Product Focus: ADCs and DACs
Makers of analog ICs are constantly evolving their DAC and ADC chips pushing the barriers of resolution and speeds. This new Product Focus section updates readers on this technology and provides a product album of representative ADC and DAC products.

Stepper Motor Waveforms
Using inexpensive microcontrollers, motor drivers, stepper motors and other hardware, columnist Ed Nisley built himself a Computer Numeric Control (CNC) machines. In this article Ed examines how the CNC’s stepper motors perform, then pushes one well beyond its normal limits.

Measuring Acceleration
Sensors are a fundamental part of what make smart machines smart. And accelerometers are one of the most important of these. In this article, George Novacek examines the principles behind accelerometers and how the technology works.

SOFTWARE TOOLS AND PROTOTYPING

Trace and Code Coverage Tools
Today it’s not uncommon for embedded devices to have millions of lines of software code. Trace and code coverage tools have kept pace with these demands making it easier for embedded developers to analyze, debug and verify complex embedded software. Circuit Cellar Chief Editor Jeff Child explores the latest technology trends and product developments in trace and code coverage tools.

Manual Pick-n-Place Assembly Helper
Prototyping embedded systems is an important part of the development cycle. In this article, Colin O’Flynn presents an open-source tool that helps you assemble prototype devices by making the placement process even easier.

Massage Vest Uses PIC32

330 Freeman Lead Image

Controlled with an iOS App

These Cornell graduates designed a low-cost massage vest that pairs seamlessly with a custom iOS app. Using the Microchip PIC32 for its brains, the massage vest has sixteen vibration motors that the user can control to create the best massage possible.

By Harry Freeman, Megan Leszczynski and Gargi Ratnaparkhi

As technology continues to make its way into every aspect of our lives, we are increasingly bombarded with more information and given more tools to organize our busy days. For our final project in the Digital Design Using Microcontrollers class at Cornell University, we sought to build technology to help us slow down, enjoy the moment and appreciate our senses. With that in mind, we built a low-cost massage vest that pairs seamlessly with a custom iOS app. The massage vest embeds 16 vibration motors and users can control the vest to create the most comfortable and soothing massage possible. The user first provides their input through the iOS app, which allows for multiple input modes—including custom or preset. The iOS app communicates to a PIC32 microcontroller via a Bluetooth Low Energy (BLE) module and ultimately the PIC32 turns on the vibration motors to complete the user’s requests. A block diagram is shown in Figure 1. Throughout the massage, users can update their settings to adjust to their desires. The complete massage vest costs less than $100—competitive with mass produced massage vests.
330 Freeman Fig 1 for web
Massage vests have historically been used for both pleasure and therapeutic purposes. Several known iOS-controlled massage vests include the iMusic BodyRhythm from iCess Labs and the i-Massager from E-Tek—both presented at the Consumer Electronics Show (CES) in 2013. The former syncs a massage to music for the user’s enjoyment, while the latter provides Transcutaneous Electrical Nerve Stimulation (TENS) as a certified medical device to relieve chronic pain. A group of Cornell students also won an Innovation Award in 2013 from the Cornell University School of Electrical and Computer Engineering for a massage vest called the Sonic Destressing Vest. The Sonic Destressing vest claimed to reduce the serum cortisol levels of its users, potentially reducing the risk of heart disease and depression—among many other chronic issues related to high serum cortisol levels. Those three vests motivated us to build a multi-purpose massage vest that could be extended to provide the particular features of those vests if desired—serving an existing base of users.

This article describes the details of how our massage vest worked so you can build one for yourself. First, we’ll discuss the hardware design that creates the comforting experience the user has with the vest. This will be followed by a discussion of the software that integrates the components together and provides a friendly user interface. Finally, we will conclude with testing and results. …

Read the full article in the January 330 issue of Circuit Cellar

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January Circuit Cellar: Sneak Preview

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                                     IMPROVING EMBEDDED SYSTEM DESIGNS

Special Feature: Powering Commercial Drones
The amount of power a commercial drone can draw on has a direct effect on how long it can stay flying as well as on what tasks it can perform. Circuit Cellar Chief Editor Jeff Child examines solar cells, fuel cells and other technology options for powering commercial drones.

CC 330 CoverFPGA Design: A Fresh Take
Although FPGAs are well established technology, many embedded systems developers—particularly those used the microcontroller realm—have never used them before. In this article, Faiz Rahman takes a fresh look a FPGAs for those new to designing them into their embedded systems.

Product Focus: COM Express boards
COM Express boards provide a complete computing core that can be upgraded when needed, leaving the application-specific I/O on the baseboard. This brand new Product Focus section updates readers on this technology and provides a product album of representative COM Express products.

TESTING, TESTING, 1, 2, 3

LF Resonator Filter
In Ed Nisley’s November column he described how an Arduino-based tester automatically measures a resonator’s frequency response to produce data defining its electrical parameters. This time he examines the resultsand explains a tester modification to measure the resonator’s response with a variable series capacitance.

Technology Spotlight: 5G Technology and Testing
The technologies that are enabling 5G communications are creating new challenges for embedded system developers. Circuit Cellar Chief Editor Jeff Child explores the latest digital and analog ICs aimed at 5G and at the test equipment designed to work with 5G technology.

                                     MICROCONTROLLERS IN EVERYTHING

MCU-based Platform Stabilizer
Using an Inertial Measurement Unit (IMU), two 180-degree rotation servos and a Microchip PCI MCU, three Cornell students implemented a microcontroller-based platform stabilizer. Learn how they used a pre-programmed sensor fusion algorithm and I2C to get the most out of their design.

Designing a Home Cleaning Robot (Part 2)
Continuing on with this four-part article series about building a home cleaning robot, Nishant Mittal this time discusses the mechanical aspect of the design. The robot is based on Cypress Semiconductor’s PSoC microcontroller.

Massage Vest Uses PIC32 MCU
Microcontrollers are being used for all kinds of things these days. Learn how three Cornell graduates designed a low-cost massage vest that pairs seamlessly with a custom iOS app. Using the Microchip PIC32 for its brains, the massage vest has sixteen vibration motors that the user can control to create the best massage possible.

AND MORE FROM OUR EXPERT COLUMNISTS:

Five Fault Injection Attacks
Colin O’Flynn returns to the topic of fault injection security attacks. To kick off 2018, he summarizes information about five different fault injection attack stories from 2017—attacks you should be thinking about as an embedded designer.

Money Sorting Machines (Part 2)
In part 1, Jeff Bachiochi delved into the interesting world of money sort machines and their evolution. In part 2, he discusses more details about his coin sorting project. He then looks at a typical bill validator implementation used in vending systems.

Overstress Protection
Last month George Novacek reviewed the causes and results of electrical overstress (EOS). Picking up where that left off, in this article he looks at how to prevent EOS/ESD induced damage—starting with choosing properly rated components.

December Circuit Cellar: A Sneak Preview

The December issue of Circuit Cellar magazine is coming soon. Want a sneak peak? We’ve got a great selection of excellent embedded electronics articles for you.

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MICROCONTROLLERS IN MOTION

Special Feature: Electronics for Wearable Devices
Circuit Cellar Chief Editor Jeff Child examines how today’s microcontrollers, sensors and power electronics enable today’s wearable products.

329 Cover Screen CapSimulating a Hammond Tonewheel Organ
(Part 2)

Brian Millier continues this two-part series about simulating the Hammond tonewheel organ using a microcontrollers and DACs. This time he examines a Leslie speaker emulation.

Money Sorting Machines (Part 1)
In this new article series, Jeff Bachiochi looks the science, mechanics and electronics that are key to sorting everything from coins to paper money. This month he discusses a project that uses microcontroller technology to sort coins.

Designing a Home Cleaning Robot (Part 1)
This four-part article series about building a home cleaning robot starts with Nishant Mittal discussing his motivations behind to his design concept, some market analysis and the materials needed.

SPECIAL SECTION: GRAPHICS AND VISION

Designing High Performance GUI
It’s critical to understand the types of performance problems a typical end-user might encounter and the performance metrics relevant to user interface (UI) design. Phil Brumby of Mentor’s Embedded Systems Division examines these and other important UI design challenges.

Building a Robotic Candy Sorter
Learn how a pair of Cornell graduates designed and constructed a robotic candy sort. It includes a three degree of freedom robot arm and a vision system using a Microchip PIC32 and Raspberry Pi module.

Raster Laser Projector Uses FPGA
Two Cornell graduates describe a raster laser projector they designed that’s able to project images in 320 x 240 in monochrome red. The laser’s brightness and mirrors positions are controlled by an FPGA and analog circuitry.

ELECTRICITY UNDER CONTROL

Technology Spotlight: Power-over-Ethernet Solutions
Power-over-Ethernet (PoE) enables the delivery of electric power alongside data on twisted pair Ethernet cabling. Chief Editor Jeff Child explores the latest chips, modules and other gear for building PoE systems.

Component Overstress
When an electronic component starts to work improperly, Two likely culprits are electrical overstress (EOS) and electrostatic discharge (ESD). In his article, George Novacek breaks down the important differences between the two and how to avoid their effects.

AND MORE FROM OUR EXPERT COLUMNISTS:

Writing the Proposal
In this conclusion to his “Building an Embedded Systems Consulting Company” article series, Bob Japenga takes a detailed look at how to craft a Statement of Work (SOW) that will lead to success and provide clarity for all stakeholders.

Information Theory in a Nutshell
Claude Shannon is credited as one of the pioneers of computer science thanks to his work on Information Theory, informing how data flows in electronic systems. In this article, Robert Lacoste provides a useful exploration of Information Theory in an easily digestible way.

November Circuit Cellar: A Sneak Preview

The November issue of Circuit Cellar magazine is coming soon. Want a sneak peak? We’ve got a great section of excellent embedded electronics articles for you.

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

Here’s a sneak preview of November Circuit Cellar:

TECHNOLOGY IN A CONNECTED WORLD

IoT Gateway Advances Take Diverse Paths: Flexible Networked Solutions
The Internet-of-Things (IoT) phenomenon offers huge opportunities. Circuit Cellar Chief Editor Jeff Child explores how IoT gateways play a vital role in those systems by providing Nov 328 coverbidirectional communication between the devices in the field and the cloud.

Power Analysis Attack on RSA: Asymmetric Adventures
Colin O’Flynn has done a number of great columns about cryptography—in particular symmetric cryptography. This time he’s tackling an asymmetric algorithm: a RSA implementation. Colin describes what’s unique about an RSA cryptosystem and takes us through a power analysis attack.

FOCUS ON ANALOG

Analog Solutions Fuel Industrial System Needs: Connectivity, Control and IIoT
Whether it’s connecting with analog sensors or driving actuators, analog ICs play many critical roles in industrial applications. Here, Circuit Cellar Chief Editor Jeff Child examines the latest analog technologies and products serving the needs of today’s industrial systems.

Using Power Audio Amplifiers in Untypical Ways (Part 2): More Alternative Uses
In Part 1 Petre Petrov described many interesting ways to use power audio amplifiers (PAAs) as universal building blocks similar to the op amps and comparators. Here, he discusses several more things that can be built from PAAs including wave generators and transformer drivers.

SPOTLIGHT ON MONITORING AND TESTING

Gas Monitoring and Sensing (Part 2): Putting the Sensor to Work
Columnist Jeff Bachiochi continues his exploration of gas monitoring and sensing. This time he discusses some of the inexpensive sensors available that can be applied to this application. Jeff then tackles the factors to consider when calibrating these sensors and how to use them effectively.

Logger Device Tracks Amp Hours (Part 2): Alternative Energy Sources
n this follow on to Part 1 of his story, William Wachsmann describes putting to use the amp-hour logger he built using a microcontroller and a clamp-on ammeter. This time he discusses modifying the amp-hour software so it can be used as an analog input logger to measure solar and wind power.

Negative Feedback in Electronics: A Look at the Opposite Side
Complementing his discussion last month on positive feedback, columnist George Novacek now takes a look at negative feedback. Just like positive feedback, negative feedback can significantly change or modify a circuit’s performance.

LF Quartz Resonator Tester: A Stimulating Discussion
Ed Nisley returns to the rich topic of low-frequency quartz resonators. This time he describes a tester built with an ordinary Arduino Nano and an assortment of inexpensive RF modules.

INTERESTING EMBEDDED PROJECTS

Simulating a Hammond Tonewheel Organ (Part 1) Mimicking a Mechanical Marvel
Hammond tonewheel organs were based upon additive sine-wave synthesis. Because of that, it’s possible to simulate the organ using a microcontroller program that feeds its output waveform to a DAC. Brian Millier takes on this project, making use of an ARM-based Teensy module to do the heavy lifting.

Machine Auto-Sorts Resistors: MCUs, Measurement and Motor Control
Typical electronics lab benches become littered with resistors from past projects. These three Cornell University graduates tackled this problem by building a resistor sorting system. It enables users to input multiple resistors, measure their resistance and sort them. The project integrates motor controllers, resistance measurement and a graphical user interface.

$50 Off Two Vyper Single-Channel Motor Controls

Exclusive for Circuit Cellar readers:  $50 off when you buy two Vyper single-channel motor controllers. Normally $500, get a pair for only $450 – a 10% discount! Contact Chris at Robot Power and mention the Circuit Cellar offer. This offer expires March 31, 2016.

Vyper

Vyper

The Robot Power Vyper is a powerful compact single channel motor control.  Featuring low-resistance MOSFETs and up to 42 V operating voltage, the Vyper can handle 120 A of continuous current with peaks over 250 A. The Vyper features RC servo and voltage/pot inputs for flexible control.  Unlike most competing units the Vyper is safe to use with bench power supplies and will not over discharge Lithium batteries.

The MegaMoto line of motor controllers for Arduino stack neatly on top of an Arduino Uno, Mega or compatible to provide high current motor control to the Arduino developer. The MegaMoto family consists of three units with current capacity ranging from 12 A to 65 A peak and a 28-V operating maximum. The MegaMoto and MegaMoto Plus allow up to three units to be stacked on a single Arduino Uno while the MegaMoto GT offers 35 A continuous current capability and includes a cooling fan.

Robot Power products allow you to control motors much larger than the “toy”-sized motors driven by most hobby and educational controllers. We allow you to complete “human scale” projects for transportation, robotics and whatever you can dream up. The Vyper controller was used by many of the competitors (including the champion) in the 2015 ABC TV show BattleBots. We also offer consulting services to customize the exact motor driver you need to complete your project or product. Give us a call or email to discuss your latest world changing invention. All Robot Power motor controls are proudly made in the USA.

Robot Power | www.robotpower.com | 2745 Martin Way E, Suite D | Olympia, WA 98506 USA 

Mouser’s New Motor Control Application Site

Mouser Electronics recently launched a new Motor Control Applications site for motor control engineers and anyone interested in control applications. The site features motor control resources and offers components available from Mouser Electronics for building motor control systems.

The site’s Applications section segments motor control into five main subsections: Permanent Magnet Synchronous motors, Brushless DC motors, Stepper motors,AC Induction motors, and Low Voltage DC motors. These subsections describe each motor’s use and operation. You can view functional block diagrams explanations of each block, as well as a parts list of products available for same-day shipping.

Source: Mouser

Source: Mouser

The Articles section covers topics such as Introduction to Rotary Resolvers & Encoders and Passive Components for Advanced Motor Control.

The Featured Products section focuses on key products available from Mouser.com that speed and enhance the construction of motor control systems. Products include the Vishay Widebody VOW3120 2.5A IGBT and MOSFET Driver, Molex Sealed Industrial USB Solutions, and the Fairchild FAN9673 CCM PFC Controller. Additional products for motor control systems include products for EMI suppression, circuit protection, passives, sensors, and motor control development kits.

The Resources section features videos, application notes, and white papers that cover topics such as device selection and system considerations when designing motor control systems. Systems discussed include selecting motor drivers, implementing control feedback loops, Power Factor Correction (PFC) techniques, and designing for thermal management.

Source: Mouser

ARM-based Embedded Power Family for Smart Motor Control

In mid-November 2014, Infineon announced an ARM-based Embedded Power family of bridge drivers offering an unmatched level of integration to address the growing trend towards intelligent motor control for a wide range of automotive applications.  The Embedded Power family offers 32-bit performance in an application space that it is typically associated with 16-bit. Sample quantities of the first members of the Embedded Power family are available for the TLE987x series for three-phase (brushless DC) motors and the TLE986x series for two-phase (DC) motors.Infineon-Embedded-Power-IC_VQFN-48

Infineon combined its proprietary automotive qualified 130-nm Smart Power manufacturing technology with its vast experience in motor control drivers into the new, highly integrated Embedded Power family, available in a standard QFN package of only 7 mm × 7 mm in dimension. Where previous multi-chip designs needed a standalone microcontroller, a bridge driver, and a LIN transceiver, automotive system suppliers now benefit from motor control designs of minimum external components count. The newly released Embedded Power products reduce the component count down to less than 30, thus allowing integration of all functions and associated external components for the motor control in a PCB area of merely 3 cm². As a result, the Embedded Power family enables the integration of electronics close to the motor for true mechatronic designs.

Both the TLE987x and TLE986x bridge drivers use the ARM Cortex TM-M3 processor. Their peripheral set includes a current sensor, a successive approximation 10-bit ADC synchronized with the capture and compare unit (CAPCOM6) for PWM control and 16-bit timers. A LIN transceiver is integrated to enable communication to the devices along with a number of general-purpose I/Os. Both series include an on-chip linear voltage regulator to supply external loads. Their flash memory is scalable from 36 to 128 KB. They operate from 5.4 V up to 28 V. An integrated charge pump enables low-voltage operation using only two external capacitors. The bridge drivers feature programmable charging and discharging current. The patented current slope control technique optimizes the system EMC behavior for a wide range of MOSFETs. The products can withstand load dump conditions up to 40 V while maintaining an extended supply voltage operating down to 3.0V where the microcontroller and the flash memory are fully functional.

The TLE987x series of bridge drivers addresses three-phase (BLDC) motor applications such as fuel pumps, HVAC blowers, engine cooling fans, and water pumps. It supports sensor-less and sensor-based (including field-oriented control) BLDC motor applications addressed by LIN or controlled via PWM.

The TLE986x series is optimized to drive two-phase DC motors by integrating four NFET drivers. The TLE986x series is suitable for applications such as sunroofs, power window lifts and generic smart motor control via NFET H-Bridge.

Engineering samples of the TLE987x and TLE986x bridge drivers in a space-saving VQFN-48 package are available with volume production planned to start in Q1 2015. For both series, there are several derivatives available, differing for example in system clock (24 MHz or 40 MHz) and flash sizes.

Source: Infineon

 

New 40-nm Microcontrollers for Motor Control

Renesas Electronics Corp. recently announced the RH850/C1x series of 32-bit microcontrollers (MCUs), which it said are designed for motor control in hybrid electric vehicles (HEVs) and electric vehicles (EVs). Based on Renesas’s 40-nm process, the RH850/C1x series features the RH850/C1H and RH850/C1M MCUs, which enable embedded designers to enhance efficiency, reduce system costs, and achieve higher safety levels for HEV/EV motor control systems.

Source: Renesas Electronics Corp.

Source: Renesas Electronics Corp.

The new RH850/C1x devices can be used with the RAA270000KFT RH850 family power supply management IC (PMIC), which is currently available in sample quantities. The power management IC integrates into one device all the power supply systems required for MCU operation, two external sensor power supply tracks, and a full complement of monitoring and diagnostic functions, significantly reducing the user burden associated with power supply system design.

The RH850/C1H and RH850/C1M MCUs incorporate large memory capacities achieved through 40 nm MONOS process technology. The RH850/C1x series is based on Renesas’s metal oxide nitride oxide silicon (MONOS) embedded flash, which has an extensive track record in mass production. The MONOS characteristics include fast readout, low power consumption, and large storage capacity. The RH850/C1M and RH850/C1H devices offer memory capacities of 2 MB and 4 MB, respectively. In addition, 32-KB data flash memory, with essentially the same functionality as EEPROM, is included for data storage.

The microcontrollers also feature an extensive set of peripheral functions for HEV/EV motor control. The RH850/C1x MCUs can implement three types of motor control in hardware: sine wave PWM, over modulation, and square wave.

Samples of the RH850/C1H and RH850/C1M MCUs are scheduled to be available from the beginning of 2015 and will cost $45 and $50 per unit, respectively. Mass production is scheduled for May 2016 and is expected to reach a scale of 100,000 units per month.

Source: Renesas Electronics Corp.