Boost Arduino Mega Capability with 512-KB SRAM & True Parallel Bus Expansion

The Arduino MEGA-2560 is a versatile microcontroller board, but it has only 8 KB SRAM. SCIDYNE recently developed the XMEM+ to enhance a standard MEGA in two ways. It increases SRAM up to 512 KB and provides True Parallel Bus Expansion. The XMEM+ plugs on top using the standard Arduino R3 stack-through connector pattern. This enables you to build systems around multiple Arduino shields. Once enabled in software, the XMEM+ becomes an integral part of the accessible MEGA memory.Scidyne

The XMEM+ also provides a fixed 23K Expansion Bus for connecting custom parallel type circuitry. Buffered Read, Write, Enable, Reset, 8-bit Data, and 16-bit Address signals are fully accessible for off-board prototyping. The XMEM+ makes any Arduino MEGA system much better suited for memory-intensive applications involving extended data logging, deep memory buffers, large arrays, and complex data structures. Target applications include industrial control systems, signage, robotics, IoT, product development, and education.

The introductory price is $39.99.

Source: SCIDYNE Corp.

Low-Power Apollo Microcontroller Now in Volume Production

Ambiq Micro’s Apollo MCU—which was demonstrated to consume less than half the energy of other microcontrollers in real-world applications (EEMBC ULPBench benchmark)—is now available for shipping for high-volume consumer applications. The microcontroller features active mode current around 34 µA/MHz when running from flash memory and sleep mode current less than 150 nA. Built around an ARM M4 core with a floating-point unit, it’s available with 64 to 512 KB of embedded flash memory. In addition, it includes a 10-bit ADC and a variety of serial interfaces.  AMB012 Ambiq Available in both BGA and WLCSP packages, the Apollo MCU is available for immediate delivery with prices starting at $1.50 in 10,000-unit quantities.

Source: Ambiq Micro

STMicro’s New Advanced 32-Bit Secure Microcontroller

STMicroelectronics has introduced the first member of the third generation of its ST33 series of secure microcontrollers based on the 32-bit ARM SecurCore SC300 processor. The ST33J2M0, which provides 2-MB flash program memory, is intended for secure applications including embedded Secure Element (eSE), Single Wire Protocol (SWP) SIMs for NFC applications, and embedded Universal Integrated Circuit Card (UICC). The secure microcontroller includes the highest performance and integrated crypto-accelerators that together with the industry’s fastest clock speed in a secure microcontroller enable the highest performance for fast application execution. It also features a new hardware architecture with strong and multiple fault-protection mechanisms covering the CPU, memories, and buses to facilitate the development of highly secure software.s.

The ST33J2M0 features multiple hardware accelerators for advanced cryptographic functions. The EDES peripheral provides a secure Data Encryption Standard (DES) algorithm implementation, while the NESCRYPT crypto-processor efficiently supports the public key algorithm. The AES peripheral ensures secure and fast AES algorithm implementation.

ST33J2M0 samples are available as wafers or housed in VQFN and WLCSP packages.

Build a Hand-Held Microcontroller-Based Scoring Device

The QuizWiz is an innovative hand-held device that teachers can use to score multiple choice tests. It’s unlikely that you’ll need such a device, but you’ll surely learn a lot from Paul Kiedrowski’s description of the design process. He covers the circuit design, hardware analysis, software, and more.

1—The prototype QuizWiz sports a 2 × 8 character LCD display and just two operating switches labeled “scores” and “save.” The quiz format can be seen here, requiring a starting sync section, dark areas between answer selections, and a minimum amount of white space between questions. A mini-DIN connector is on one end to provide an optional serial port interface.

Photo 1: The prototype QuizWiz sports a 2 × 8 character LCD display and just two operating switches labeled “scores” and “save.”

Kiedrowski writes:

For automatic scoring of multiple choice tests, many schools use a commercially available system based on a desktop card reader machine, which requires that students mark their answers on preprinted forms of specific size and layout. This method is expensive because of the equipment and score cards, therefore usually it’s used only for critical testing.

In most cases, because only one centralized scoring machine is available to teachers, it is not located in the classroom where it would offer the most convenience. Perhaps more importantly, the most useful time to evaluate test results is immediately after a test so that feedback could be given and the missed questions discussed promptly. This is especially desirable for periodic quizzes where the intent is to allow the teacher to quickly gauge the classroom’s learning progress. What is needed is a better, lower cost, convenient way of quickly scoring quizzes.

Introducing the QuizWiz

To answer these needs, I developed a hand-held scoring device based on an 8-bit microprocessor I dubbed QuizWiz. The 87LPC764 is a new 20-pin offering that combines fast speed, 8051 code compatibility, and low cost. This processor is ideally suited for this project because of its 4K code space, power-saving modes, serial port, and remaining 16 I/O pins. Philips wanted to create a device simple to operate and affordable enough that every teacher could own one (see Photo 1).

QuizWiz has several features that make the teacher’s ability to score multiple-choice quizzes fast and easy. It reduces scoring time to only 10–15 s per page. It is capable of scoring tests printed on standard paper without preprinted forms, using a word-processing template.

QuizWiz does not require machine-assisted paper handling mechanisms. Also, as a hand-held device, it operates on three AAA batteries. The processor is inexpensive ($30 for parts) and measures only 6″ × 1.7″ × 1.0″. Simple to learn, the new teacher’s aid requires only two buttons to operate.

An eight-character by two-row LCD displays the status and results. There is a buzzer to provide distinctive audio feedback. QuizWiz has automatic power shutdown, providing a long life (estimated at >100 quiz sets). The flexible quiz format allows multiple columns and/or pages.

For your convenience, there is temporary memory storage of results during power shutdowns. Totals, per question and per quiz, are available. QuizWiz can handle eight choices per question, four columns of questions, and 32 questions per quiz. The processor provides an RS-232 serial connection for uploading results in real time to a PC, which allows tracking of which questions were missed per student.

1—Here you can see the 87LPC764 processor, MAX221 RS-232 interface, and MAX710 DC/DC converter. The device supplies 5 V to the LCD, which uses a 4-bit interface to save I/O pins.

Figure 1: Here you can see the 87LPC764 processor, MAX221 RS-232 interface, and MAX710 DC/DC converter. The device supplies 5 V to the LCD, which uses a 4-bit interface to save I/O pins.

Circuit Description

Figure 1 shows the circuitry has been partitioned by the two chassis sections. A PCB in the lower half contains most of the components, whereas the sensor tip, LCD, and battery compartment are in the upper half. The processor was DIP socketed for the development phase (see Photo 2).

A design-for-manufacturing approach was taken for the construction of the aluminum-chassis prototype. The main two-sided PCB has ample room for parts, mainly because of the housing size needed to fit the AAA battery pack and LCD display.

Photo 2: The main two-sided PCB has ample room for parts, mainly because of the housing size needed to fit the AAA battery pack and LCD.

A single reflective opto-sensor was chosen to perform the scanning detection process, with an optimum sensor-to-paper distance of 1.0 mm. To preserve battery power, the opto-sensor LED is only activated when QuizWiz is pressed against the paper, which depresses a mechanical switch located in the tip. An alternate scheme initially considered required two sensors, the second one used for scanning a parallel column of markings intended only to synchronize the scan position. The additional LED would have significantly increased the power consumption, however.

Normal battery operating current is approximately 25 mA when all circuits are operating, 15 mA when not scanning, and 20 mA during shutdown. Using three AAA batteries in series, with a typical capacity of 1000 mA/h, the teacher can score approximately 100 quizzes for a classroom of 30 students.

QuizWiz uses a simple three-chip design consisting of the processor, a 5-V DC/DC converter, and an RS-232 three-wire interface. The 87LPC764 is a good match for the required QuizWiz features, because all of its pins and most of its features are used in this project. The only features not used are the I2C interface and analog comparators. To minimize cost further, no external crystal is required, because the processor conveniently includes an internal 6-MHz RC oscillator..

Paul Kiedrowski’s article, “QuizWiz: A Hand-Held Scoring Device,” originally appeared in Circuit Cellar 125, 2000. Download the article

New 32-Bit MCU Series for Embedded Control and Touch

Microchip Technology recently announced a new series within its PIC32MX1/2 32-bit microcontroller family that features a 256-KB flash configureation and 16-KB of RAM. The microcontrollers provide flexibility to low-cost applications that need complex algorithms and application code. More specifically, they are intended to help designers looking to develop products with capacitive touch screens or touch buttons, as well as USB device/host/OTG connectivity.Microchip PIC32mx1

The PIC32MX1/2 MCU series provides  up to 50 MHz/83 DMIPS performance for executing advanced control applications and mTouch capacitive touch sensing. In addition, it has an enhanced 8-bit Parallel Master Port (PMP) for graphics or external memory, a 10-bit, 1-Msps, 13-channel ADC, support for SPI and I2S serial communications interfaces, and USB device/host/On-the-Go (OTG) functionality.

Microchip’s MPLAB Harmony software development framework further simplifies designs by integrating the license, resale, and support of Microchip and third-party middleware, drivers, libraries and Real-Time Operating Systems (RTOS). Specifically, Microchip’s readily available software packages—including USB stacks and Graphics and Touch libraries—can greatly reduce the development time of applications such as consumer, industrial and general-purpose embedded control.

These latest PIC32MX1/2 MCUs are available now in 28-pin QFN, SPDIP ,and SSOP packages and 44-pin QFN, TQFP and VTLA packages. Pricing starts at $1.91 each, in 10,000-unit quantities.

Source: Microchip Technology

STMicro Introduces STM32F7 MCUs with Advanced ARM Cortex-M7 Core

STMicroelectronics has begun producing microcontrollers with the new ARM Cortex-M7 processor, which is the newest Cortex-M core for advanced consumer, industrial, and Internet-of-Things (IoT) devices. The new STM32F7 microcontrollers combine the Cortex-M7 core with advanced peripherals. STMicro_STM32_Volume_Disc_Kit

The STM32F7 Discovery Kit includes the STM32Cube firmware library along with support from software-development tool partners and the ARM mbed online community. The $49 Discovery Kit includes a WQVGA touchscreen color display, stereo audio, multi-sensor support, security, and high-speed connectivity. In addition to an integrated ST-Link debugger/programmer (you don’t need a separate probe), you get unlimited expansion capability via the Arduino Uno connectivity support and immediate access to a wide variety of specialized add-on boards.

STM32F7 devices are available in a range of package options from a 14 mm × 14 mm LQFP100 to 28 mm × 28 mm LQFP208, plus 10 mm × 10 mm 0.65-mm-pitch UFBGA176, 13 mm × 13 mm 0.8 mm-pitch TFBGA216, and 5.9 mm × 4.6 mm WLCSP143. Prices start at $6.73 for the STM32F745VE in 100-pin LQFP with 512-KB on-chip flash memory (in 1,000-unit orders).

The STM32F7 development ecosystem includes both the Discovery Kit and two evaluation boards (STM32746G-EVAL2 and STM32756G-EVAL2) that cost $560 each. The STM32F7 Discovery Kit (STM32F746G-DISCO) gives full flexibility to fine-tune hardware and software at any time. You also benefit from the associated STM32CubeF7 firmware, and the ability to re-use all STM32F4 software assets due to code compatibility.

Source: STMicroelectronics

Happy Gecko MCU Family Simplifies USB Connectivity for IoT Apps

Silicon Labs recently introduced new energy-friendly USB-enabled microcontrollers (MCUs). Part of its EFM32 32-bit MCU portfolio, the new Happy Gecko MCUs are designed to deliver the lowest USB power drain in the industry, enabling longer battery life and energy-harvesting applications. Based on the ARM Cortex-M0+ core and low-energy peripherals, the Happy Gecko family simplifies USB connectivity for a wide range of Internet of Things (IoT) applications including smart metering, building automation, alarm and security systems, smart accessories, wearable devices, and more.SiliconLabsEFM32

Silicon Labs developed the Happy Gecko family to address the rising demand for cost-effective, low-power USB connectivity solutions. With more than 3 billion USB-enabled devices shipping each year, USB is the fastest growing interface for consumer applications and is also gaining significant traction in industrial automation. In today’s IoT world, developers have discovered that adding USB interfaces to portable, battery-powered connected devices can double the application current consumption. Silicon Labs’ Happy Gecko MCUs provide an ideal energy-friendly USB connectivity solution for these power-sensitive IoT applications.

Happy Gecko USB MCUs feature an advanced energy management system with five energy modes enabling applications to remain in an energy-optimal state by spending as little time as possible in active mode. In deep-sleep mode, Happy Gecko MCUs have an industry-leading 0.9-μA standby current consumption (with a 32.768-kHz RTC, RAM/CPU state retention, brown-out detector and power-on-reset circuitry active). Active-mode power consumption drops down to 130 µA/MHz at 24 MHz with real-world code (prime number algorithm). The USB MCUs further reduce power consumption with a 2-µs wakeup time from Standby mode.

Like all EFM32 MCUs, the Happy Gecko family includes the Peripheral Reflex System (PRS) feature, which greatly enhances overall energy efficiency. The six-channel PRS monitors complex system-level events and allows different MCU peripherals to communicate autonomously with each other without CPU intervention. The PRS watches for specific events to occur before waking the CPU, thereby keeping the Cortex-M0+ core in an energy-saving standby mode as long as possible, reducing system power consumption and extending battery life.

Happy Gecko MCUs feature many of the same low-energy precision analog peripherals included in other popular EFM32 devices. These low-energy peripherals include an analog comparator, supply voltage comparator, on-chip temperature sensor, programmable current digital-to-analog converter (IDAC), and a 12-bit analog-to-digital converter (ADC) with 350 μA current consumption at a 1 MHz sample rate. On-chip AES encryption enables the secure deployment of wireless connectivity for IoT applications such as smart meters and wireless sensor networks.

The Happy Gecko family’s exceptional single-die integration enables developers to reduce component count and bill-of-materials (BOM) cost. While typical USB connectivity alternatives require external components such as crystals and regulators, the highly integrated Happy Gecko MCUs eliminate nearly all of these discretes with a crystal-less architecture featuring a full-speed USB PHY, an on-chip regulator and resistors. Happy Gecko MCUs are available in a choice of space-saving QFN, QFP and chip-scale package (CSP) options small enough for use in USB connectors and thin-form-factor wearable designs.

The Happy Gecko family is supported by Silicon Labs’ Simplicity Studio development platform, which helps developers simplify low-energy design. The Simplicity Energy Profiler enables real-time energy profiling and debugging of code. The Simplicity Battery Estimator calculates expected battery life based on an application profile, energy modes and peripherals in use. The Simplicity Configurator provides a visual interface for MCU pin configuration, automatically generating initialization code. Code developed for other EFM32 MCUs can be reused with Happy Gecko applications. Developers can download Simplicity Studio and access Silicon Labs’ USB source code and software examples at no charge at

To help developers move rapidly from design idea to final product, the Happy Gecko family is supported by the ARM mbed ecosystem, which includes new power management APIs developed by Silicon Labs and ARM. These low-power mbed APIs are designed with low-energy application scenarios in mind, enabling rapid prototyping for energy-constrained IoT designs. ARM mbed APIs running on EFM32 MCUs automatically enable the optimal sleep mode based on the MCU peripherals in use, dramatically reducing system-level energy consumption. The Happy Gecko starter kit supports ARM mbed right out of the box. Silicon Labs has also launched mbed API support for Leopard, Giant, Wonder and Zero Gecko MCUs.  For additional ARM mbed information including access to mbed software, example code, services and the mbed community, visit

The Happy Gecko family includes 20 MCU devices providing an array of memory, package and peripheral options, as well as pin and software compatibility with Silicon Labs’s entire EFM32 MCU portfolio. Samples and production quantities of Happy Gecko MCUs are available now in 24-pin and 32-pin QFN, 48-pin QFP and 3 mm × 2.9 mm CSP packages. Happy Gecko MCU pricing in 10,000-unit quantities begins at $0.83. The Happy Gecko SLSTK3400A starter kit costs $29.

Source: Silicon Labs

High-Accuracy, 3-D Magnetic Sensor

Infineon Technologies recently announced the availability of the TLV493D-A1B6, a 3-D magnetic sensor that features highly accurate three-dimensional sensing with extremely low power consumption in a small six-pin TSOP package. Magnetic field detection in x, y, and z directions enables the sensor to measure 3-D, linear, and rotation movements. The implemented digital I²C interface enables fast and bidirectional communication between the sensor and microcontroller.3D-Magnetic-Sensor_TSOP6_Infineon

The TLV493D-A1B6 is intended for consumer and industrial applications that require accurate 3-D measurements or angular measurements or low power consumption, such as joysticks, electric meters where the 3-D magnetic sensor helps to protect against tampering, and more. With its contactless position sensing and high temperature stability of magnetic threshold, the TLV493D-A1B6 enables these systems to become smaller, more accurate, and robust.

The 3-D magnetic sensor TLV493D-A1B6 enables smaller and more energy efficient e-meter systems. Today, up to three magnetic sensors—one for each dimension of external magnetic field—are needed to measure tampering attempts with large magnets. In future, the 3-D magnetic sensor TLV493D-A1B6 will replace all 3-D sensors thus making e-meters smaller and more energy efficient.

The 3-D sensor TLV493D-A1B6 detects all three dimensions of a magnetic field. Using lateral hall plates for the z direction and vertical Hall plates for the x and y direction of the magnetic field, the sensor can be used in a large magnetic field range of ±150 mT for all three dimensions. This allows measuring and covering a long magnet movement. The large operation scale also makes the magnet circuit design easy, robust and flexible.

The TLV493D-A1B6 provides 12-bit data resolution for each measurement direction. This allows a high data resolution of 0.098 mT per bit (LSB) so that even the smallest magnet movements can be measured.

One of the main development goals for the TLV493D-A1B6 sensor was low power consumption. In Power Down mode, the sensor only requires 7-nA supply current. To perform magnetic measurements, the sensor can be set in one of five different power modes. In Ultra Low Power Mode, for example, the sensor performs a magnetic measurement every 100 ms (10 Hz) resulting in a current consumption of 10 µA. The time between measurement cycles can be set flexibly allowing system specific solutions. Using the sensor with continuous measurements, the maximum power consumption is only 3.7 mA. Also, the power modes can be changed during operation.

The TLV493D-A1B6 uses a standard I²C digital protocol to communicate with external microcontrollers. It is possible to operate the sensors in a bus mode to eliminate additional wiring cost and efforts.

Targeting industrial and consumer applications, TLV493D-A1B6 can be operated on supply voltages between 2.7 and 3.5 V and in a temperature range from –40°C to 125°C. The product is qualified according to industry standard JESD47.

For a fast design-in process, Infineon offers the “3D Magnetic 2Go” evaluation board. In combination with the free 3-D sensor software, first magnetic measurements are attainable within minutes. The evaluation board applies the Infineon 32-bit XMC1100 micrcontroller that uses the ARM Cortex-M0 processor.

The “3D Magnetic 2Go” is currently available ( Engineering samples of the TLV493D-A1B6 designed for consumer and industrial applications will be available as of July 2015. Volume production is expected to start in January 2016.

Source: Infineon Technologies

IoT Project: Wireless Sump Pump Monitor

Do you worry about your basement flooding? You can build a microcontroller-based, three-unit wireless system can monitor the water level in your sump pit. The Pump-Eye is a three-unit water level monitoring system built around a Freescale Semiconductor MC9S08GT60 and MC9S12NE64 microcontrollers.

1—A hose connects the Pump-Eye sensor unit to a copper pipe. The pipe gets fastened to the side of the sump pit.

A hose connects the Pump-Eye sensor unit to a copper pipe. The pipe gets fastened to the side of the sump pit.

The sensor unit monitors the water level in a sump pump pit, the sump pump’s AC power, and the sensor unit’s backup battery. The base unit receives status information from the sensor unit via RF. The sensor and base units use MC9S08GT60 microcontrollers; they communicate with each other via 2.4-GHz transceivers based on an MC13192 SARD board. The Ethernet link creates and sends timestamp and log messages to a host when the pump runs. The system sends a warning e-mail when the water level is high or there’s a power failure. An alarm sounds when the water level exceeds the normal maximum height by 10%.

In “Wireless Sump Pump Monitoring System”  (Circuit Cellar 189), David Kanceruk writes:

The Pump-Eye is a flexible system comprised of three electronic units: a sensor unit, a base unit, and an Ethernet unit. Let’s take a look at each unit.

Figure 1—The base and Ethernet units are optional. There are five ways to set up the Pump-Eye system without having to make any software changes.

Click to enlarge. The base and Ethernet units are optional. There are five ways to set up the Pump-Eye system without having to make any software changes.

The sensor unit monitors the sump pit’s water level (see Photo 1). Data is displayed on a 10-segment LED bar graph so you don’t have to remove the sump pit’s lid to determine the water level. An alarm sounds when the water level exceeds the height you program into the system. A switch enables you to cancel the alarm at any time. LEDs illuminate when the AC power is off and when the sensor unit’s 9-V backup battery needs to be replaced.

The base unit features the same indicators as the sensor unit. It sounds the same alarm signal as the sensor unit. I chose the SOS Morse code sound (an old sound that’s recognizable to some of us) because it’s notably different than the sounds generated by my appliances. Canceling the alarm on the base unit cancels the alarm on the sensor unit and vice versa. Because the units are connected wire- lessly, I can place the base unit anywhere in my house. Therefore, I don’t have to go to my basement to read the sensor unit’s front panel.

The Ethernet unit can connect to either the sensor unit or the base unit via an RS-232 connection. I can place the Ethernet unit in the most convenient location for connecting to an uninterruptible power supply (UPS) and network. The Ethernet unit receives commands from the unit to which it’s attached. It then sends syslog messages to a syslog server so that pump cycles can be time stamped and counted. A record is kept of the pump’s run times. The Ethernet unit can also send me an e-mail or text message regarding conditions that require immediate attention (e.g., high water levels and a loss of AC power).

The sensor and base units feature Freescale MC9S08GT60 microcontrollers. They communicate with each other via 2.4-GHz ZigBee transceivers based on a Freescale MC13192 SARD board using IEEE 802.15.4 MAC soft- ware. The sensor unit monitors the sump pump’s AC power and its 9-V back-up battery.

The front panel electronics on the two units are similar, but there are a few differences. The sensor unit is larger. It also has an extra connector that’s used for passing signals to the rear panel’s electronics for the sensors. Because the base unit simply acts as a remote display to show what’s happening on the sensor unit, it doesn’t need sensing electronics on the rear panel.

When you cover the top of a straw with your finger and place it in a glass of water, the air in the straw becomes pressurized. The amount of pressure depends on the height of the water in the straw, and this depends on factors such as ambient air pressure, the mass density of the water, gravity, and the height of the water outside the straw: P = Pa + rg∆h. In this formula, P is the pressure, Pa is the ambient pressure, r is the mass density of fluid, g is 9.8066 m/s2, and h is the height of fluid.

You can nullify the effect of a change in ambient pressure if you use a gauge pressure sensor to measure pressure relative to ambient pressure. The formula then becomes P = rg∆h. You can assume that the mass density of water and gravity are constants, so the pressure will be proportional to a change in the water’s height. The sensor unit measures this pressure with a Freescale MPXM2010GS temperature-compensated gauge pressure sensor. The pressure is then converted to a percentage of normal water levels observed in the sump pit.

I tried placing a hose in the sump pit to sense the water level, but I quickly discovered that it wasn’t too reliable. This was probably because of the surface tension of the water clinging to the inside of the thin hose (5/64 inches in diameter). Therefore, I decided to use a 0.5 inches in diameter copper pipe as a sensor interface. The ratio of the area affected by surface tension to the total area is less significant with the larger diameter. I bought a length 0.125 inches in diameter brass pipe to use as a nipple for the hose that connects the MPXM2010GS to the cop- per pipe. I soldered the brass pipe to a standard 0.5 inch copper cap in which I had drilled a hole. The cap is soldered to the top of the copper pipe.

The copper pipe solved the problem of holding the open end of the hose at a fixed height, and it also alleviated my concerns about dirt clogging the thin hose. A plastic clamp screwed to the side of the plastic sump pit holds the pipe in place. I had originally placed the pipe to the bottom of the sump pit, but I found a negative pressure developing in it after numerous pump cycles. I concluded that this was the result of scavenging around the bottom of the pipe because of water currents caused by the pump. Keeping the end of the pipe at the height of the low water level pre- vented this from happening.

Read the full article.

New XMC4800 Microcontrollers with EtherCAT Technology Support Industry 4.0

Infineon Technologies AG has launched a new XMC4800 series of 32-bit microcontrollers with on-chip Ethernet for Control Automation Technology (EtherCAT) node. With its real-time capability, the XMC4800 series is intended to drive networked industrial automation and Industry 4.0 applications.Infineon XMC4800

The EtherCAT node is integrated on an ARM Cortex-M-based microcontroller with on-chip flash and analog/mixed signal capability. The XMC4800 series comprises at least 18 members varying in memory capacity, temperature range and packaging. All XMC4800 microcontrollers will be AEC Q100 qualified, making them also suited for use in commercial, construction, and agricultural vehicles.

The XMC4800 series is a member of the XMC4000 family, which uses the ARM Cortex-M4 processor and was specifically developed for use in the automation of manufacturing and buildings as well as electric drives and solar inverters. The XMC4800 series offers a seamless upgrade path to EtherCAT technology with pin and code compatibility to the established XMC4000 microcontrollers. The XMC4800 enables the use of EtherCAT under the harsh condition of up to 125°C ambient temperature.


With the integration of the EtherCAT functionality, the XMC4800 enables the most compact design without need for a dedicated EtherCAT ASIC, external memory and clock crystal. It offers a 144-MHz-CPU, up to 2 MB of embedded flash memory, 352 KB of RAM and a comprehensive range of peripheral and interface functions. The peripherals include four parallel fast 12-bit A/D converter modules, two 12-bit D/A converters, four delta sigma demodulator modules, six capture/compare units (CCU4 and CCU8), and two positioning interface modules. In addition to its EtherCAT functionality, its communication functions comprise interfaces for Ethernet, USB, and SD/MMC. Also, the XMC4800 series offers six CAN nodes, six serial communication channels, and one external bus interface for communication. The three package options are LQFP-100, LQFP-144, and LFBGA-196.

Samples of the series XMC4800 with EtherCAT technology will be available in August 2015. Volume production is scheduled for Q1 2016.

Source: Infineon 



Toshiba Expands TX04 Range of ARM Cortex-M4F-Based Microcontrollers

Toshiba Electronics Europe has announced a new ARM Cortex-M4F based microcontroller for use in secure systems control. The TMPM46BF10FG expands its existing TX04 range and adds enhanced security features that are well-suited to applications in Internet of Things (IoT) devices, energy management systems, sensor technology, and industrial equipment.Toshiba TMPM46BF10FG

Users of secure communications control systems increasingly require mass memory data for firmware generation management, failure analysis, and high-precision consecutive data storage. The TMPM46BF10FG meets these requirements for high-level security features, such as tamper detection and information concealment. The IC also meets the need to reduce the number of parts on system circuit board by supporting large capacity memory.

Featuring an ARM Cortex-M4F core, with a maximum operating frequency of 120 MHz, the TMPM46BF10FG incorporates 1,024 KB of flash memory and 514-KB SRAM required for secure communications control, four types of security circuits for network communications. The microcontroller also integrates an SLC NAND flash memory controller and 4- and 8-bit error correction circuitry (BCH ECC) that supports memory expansion with 1-to-4-Gb SLC NAND flash memory chips.

To provide additional levels of safety, the IC includes a 16-channel interrupt input and a clock-independent watchdog timer, which operates separately from the system clock, improving the safety of system functions. In the case of a system clock malfunction, the watchdog timer is still capable of detecting errors.

The TMPM46BF10FG incorporates a true random number generator (TRNG: SP800-90C standard) through the combination of a random entropy seed generation (ESG) circuit and Hash-DRGB created by the secure hash processor (SHA) and software program. This meets the robust standards of security that are required in network communications. The hardware based AES encryption/decryption process meets FIPS180-4 and FIPS197 standards and reduces the load on the CPU, in combination with a random seed generation circuit (ESG), and a multiple-length arithmetic (MLA) used to calculate elliptic curves for asymmetric ciphers.

The TMPM46BF10FG features direct memory access (32 channel), a 12-bit AD converter (8 channel), 16-bit timer (8 channel), SPP (3 channel), SIO/UART (4 channel), full UART (2 channel) I2C (3 channel), with an operating voltage of 2.7 to 3.6 V. Housed in an LQFP100 package, the IC measures just 14 mm × 14 mm, with a 0.5-mm pitch.

Samples are now available. Mass production will begin in October.

Source: Toshiba



Quad Bench Power Supply

The need for a bevy of equipment for building and testing presents a problem: how to deliver an adequate power supply while keeping workbench clutter to a minimum. Brian decided to tackle this classic engineering conundrum with a small, low-capacity quad bench power supply.

To the right of the output Johnson posts are the switches that set the polarity of the floating supplies—as well as the switch that disconnects all power supply outputs—while leaving the unit still powered up.

To the right of the output Johnson posts are the switches that set the polarity of the floating supplies—as well as the switch that disconnects all power supply outputs—while leaving the unit still powered up.

In “Quad Bench Power Supply,” Millier writes:

I hate to admit it, but my electronics bench is not a pretty sight, at least in the midst of a project anyway. Of course, I’m always in the middle of some project that, more often than not, contains two or three different projects in various stages of completion. To make matters worse, most of my projects involve microchips, which have to be programmed. Because I use ISP flash memory MCUs exclusively, it makes sense to locate a computer on my construction bench to facilitate programming and testing. To save space, I initially used my laptop’s parallel port for MCU programming. It was only a matter of time before I popped the laptop’s printer port by connecting it to a prototype circuit with errors on it.

Fixing my laptop’s printer port would have involved replacing its main board, which is an expensive proposition. Therefore, I switched over to a desktop computer (with a $20 ISA printer port board) for programming and testing purposes. The desktop, however, took up much more room on my bench.

You can’t do without lots of testing equipment, all of which takes up more bench space. Amongst my test equipment, I have several bench power supplies, which are unfortunately large because I built them with surplus power supply assemblies taken from older, unused equipment. This seemed like a good candidate for miniaturization.

At about the same time, I read a fine article by Robert Lacoste describing a high-power tracking lab power supply (“A Tracking Lab Power Supply,” Circuit Cellar 139). Although I liked many of Robert’s clever design ideas, most of my recent projects seemed to need only modest amounts of power. Therefore, I decided to design my own low-capacity bench supply that would be compact enough to fit in a small case. In this article, I’ll describe that power supply.


Even though I mentioned that my recent project’s power demands were fairly modest, I frequently needed three or more discrete voltage levels. This meant lugging out a couple of different bench supplies and wiring all of them to the circuit I was building. If the circuit required all of the power supplies to cycle on and off simultaneously, the above arrangement was extremely inconvenient. In any event, it took up too much space on my bench.

I decided that I wanted to have four discrete voltage sources available. One power supply would be ground referenced. Two additional power supplies would be floating power supplies. Each of these would have the provision to switch either the positive or negative terminal to the negative (ground) terminal of the ground-referenced supply, allowing for positive or negative output voltage. Alternately, these supplies could be left floating with respect to ground by leaving the aforementioned switch in the center position.

This arrangement allows for one positive and two positive, negative or floating voltage outputs. To round off the complement, I added Condor’s commercial 5-V, 3-A linear power supply module, which I had on hand in my junk box. Table 1 shows the capabilities of the four power supplies.

I wanted to provide the metering of voltage and current for the three variable power supplies. The simultaneous voltage and current measurement of three completely independent power supplies seemed to indicate the need for six digital panel meters. Indeed, this is the path that Robert Lacoste used in his tracking lab supply.

As you can see, there are four power supplies. I’ve included all of the information you need to understand their capabilities.

As you can see, there are four power supplies. I’ve included all of the information you need to understand their capabilities.

I had used many of these DPM modules before, so I was aware of the fact that the modules require their negative measurement terminal to float with respect to the DPM’s own power supply. I solved this problem in the past by providing the DPM module with its own independent power source. Robert solved it by designing a differential drive circuit for the DPM. Either solution, when multiplied by six, is not trivial. Add to this the fact that high-quality DPMs cost about $40 in Canada, and you’ll see why I started to consider a different solution.

I decided to incorporate an MCU into the design to replace the six DPMs as well as six 10-turn potentiometers, which are also becoming expensive. In place of $240 worth of DPMs, I used three inexpensive dual 12-bit ADCs, an MCU, and an inexpensive LCD panel. The $100 worth of 10-turn potentiometers was replaced with three dual digital potentiometers and two inexpensive rotary encoders.

Using a microcontroller-based circuit basically allows you to control the bench supply with a computer for free. I have to admit that I decided to add the commercial 5-V supply module at the last minute; therefore, I didn’t allow for the voltage or current monitoring of this particular supply.


Although there certainly is a digital component to this project, the basic power supply core is a standard analog series-pass regulator design. I borrowed a bit of this design from Robert’s lab supply circuit.

Basically, all three power supplies share the same design. The ground-referenced power supply provides less voltage and more current than the floating supplies. Thus, it uses a different transformer than the two floating supplies. The ground-referenced supply’s digital circuitry (for control of the digital potentiometer and ADC) can be connected directly to the MCU port lines. The two floating supplies, in addition to the different power transformer, also need isolation circuitry to connect to the MCU.

Figure 1 is the schematic for the ground-referenced supply. As you can see, a 24VCT PCB-mounted transformer provides all four necessary voltage sources. A full wave rectifier comprised of D4, D5, and C5 provides the 16 V that’s regulated down to the actual power supply output. Diodes D6, R10, C8, and Zener diode D7 provide the negative power supply needed by the op-amps. …

The ground-referenced power supply includes an independent 5-V supply to run the microcontroller module.

The ground-referenced power supply includes an independent 5-V supply to run the microcontroller module.


As with every other project I’ve worked on in the last two years, I chose the Atmel AVR family for the MCU. In this case, I went with the AT90S8535 for a couple of reasons. I needed 23 I/O lines to handle the three SPI channels, LCD, rotary encoders, and RS-232. This ruled out the use of smaller AVR devices. I could’ve used the slightly less expensive AT90LS8515, but I wanted to allow for the possibility of adding a temperature-sensing meter/alarm option to the circuit. The ’8535 has a 10-bit ADC function that’s suitable for this purpose; the ’8515 does not.

The ’8535 MCU has 8 KB of ISP flash memory, which is just about right for the necessary firmware. It also contains 512 bytes of EEPROM. I used a small amount of the EEPROM to store default values for the three programmable power supplies. That is to say, the power supply will power up with the same settings that existed at the time its Save Configuration push button was last pressed.

To simplify construction, I decided to use a SIMM100 SimmStick module made by Lawicel. The SIMM100 is a 3.5″ × 2.0″ PCB containing the ’8535, power supply regulator, reset function, RS-232 interface, ADC, ISP programming headers, and a 30-pin SimmStick-style bus. I’ve used this module for prototypes several times in the past, but this is the first time I’ve actually incorporated one into a finished project. …

eded to operate the three SPI channels and interface the two rotary encoders come out through the 30-pin bus. As you now know, I designed the ground-referenced power supply PCB to include space to mount the SIMM100 module, as well as the IsoLoop isolators. The SIMM100 mounts at right angles to this PCB; it’s hard-wired in place using 90° header pins. The floating power supplies share a virtually identical PCB layout apart from being smaller because of the lack of traces and circuitry associated with the SIMM100 bus and IsoLoop isolators.

The SIMM100 module has headers for the ISP programming cable and RS-232 port. I used its ADC header to run the LCD by reassigning six of the ADC port pins to general I/O pins.

When I buy in bulk, it’s inevitable that by the time I use the last item in my stock, something better has taken its place. After contacting Lawicel to request a .jpg image of the SIMM100 for this article, I was introduced to the new line of AVR modules that the company is developing.

Rather than a SimmStick-based module, the new modules are 24- and 40-pin DIP modules that are meant to replace Basic Stamps. Instead of using PIC chips/serial EEPROM and a Basic Interpreter, they implement the most powerful members of Atmel’s AVR family—the Mega chips.

Mega chips execute compiled code from fast internal flash memory and contain much more RAM and EEPROM than Stamps. Even though flash programming AVR-family chips is easy through SPI, using inexpensive printer port programming cables, these modules go one step further by incorporating RS-232 flash memory programming. This makes field updates a snap. …

The user interface I settled on consisted of a common 4 × 20 LCD panel along with two rotary encoders. One encoder is used to scroll through the various power supply parameters, and the other adjusts the selected parameter. The cost of LCDs and rotary encoders is reasonable these days. Being able to eliminate the substantial cost of six DPMs and six 10-turn potentiometers was the main reason for choosing an MCU-based design in the first place.

Brian Millier’s article first appeared in Circuit Cellar 149.

ARM MCUs wtith Capacitive Touch Hardware Support for HMI and LIN Applications

Atmel recently announced its next-generation family of automotive-qualified ARM Cortext-M0+-based micrcontrollers with an integrated peripheral touch controller (PTC) for capacitive touch applications. The new SAM DA1 is the first series in this Atmel |SMART MCU automotive-qualified product family, operating at a maximum frequency of 48 MHz and reaching a 2.14 Coremark/MHz.Atmel Corporation SAM DA1

Atmel’s SAM DA1 series is ideal for capacitive touch button, slider, wheel or proximity sensing applications and offers high analog performance for greater front-end flexibility. The new devices are available down to a very compact QFN 5 × 5 mm package with wettable flanks for automated optical inspection.

Eliminating external components and offering more robust features, devices in the SAM DA1 series come with 32 to 64 pins, up to 64 KB of flash memory, 8 KB of SRAM, and 2-KB read-while-write flash memory and are qualified according to the AEC Q-100 Grade 2 (–40° to 105°C).

Key Features of Atmel’s SAM DA1 Series

  • Atmel |SMART ARM Cortex-M0+-based processor
  • 45 DMIPS
  • Vcc 2.7 to 3.63 V
  • 16- to 64-KB Flash; 32 to 64 pins
  • Up to six SERCOM (Serial Communication Interface), USB, I2S
  • Peripheral Touch Controller
  • Complex PWM
  • AEC Q100 Grade 2 Qualified

To accelerate the design development, the ATSAMDA1-XPRO development kit is available to support the new devices. The new SAM DA1 series is also supported by Atmel Studio, Atmel Software Framework and debuggers.

Contact Atmel to sample the SAM DA1 series.

Source: Atmel

New Microcontrollers Feature Advanced Analog & Digital Integration

Microchip Technology recently announced a new family of 8-bit PIC microcontrollers (MCUs) with the PIC16(L)F1769 family, which is the first to offer up to two independent closed-loop channels. This is achieved with the addition of the Programmable Ramp Generator (PRG), which automates slope and ramp compensation, increases stability and efficiencies in hybrid power conversion applications. The PRG provides real-time responses to a system change, without CPU interaction for multiple independent power channels. This allows customers the ability to reduce latency and component counts while improving system efficiency.Microchip PIC16(L)F1769

The PIC16(L)F1769 family includes intelligent analog and digital peripherals, including tristate op-amps, 10-bit ADCs, 5- and 10-bit DACs, 10- and 16-bit PWMs, and high-speed comparators, along with two 100-mA, high-current I/Os. The combination of these integrated peripherals help support the demands of multiple independent closed-loop power channels and system management, while providing an 8-bit platform that simplifies design, enables higher efficiency and increase performance while helping eliminate many discrete components in power-conversion systems.

In addition to power-conversion peripherals, these PIC MCUs have a unique hardware-based LED dimming control function enabled by the interconnections of the Data Signal Modulator (DSM), op amp and 16-bit PWM. The combination of these peripherals creates a LED-dimming engine synchronizing switching control eliminating LED current overshoot and decay. The synchronization of the output switching helps smooth dimming, minimizes color shifting, increases LED life and reduces heat. This family also includes Core Independent Peripherals (CIPs), such as the Configurable Logic Cell (CLC), Complementary Output Generator (COG), and Zero Cross Detect (ZCD). These CIPs take 8-bit PIC MCU performance to a new level, as they are designed to handle tasks with no code or supervision from the CPU to maintain operation, after initial configuration. As a result, they simplify the implementation of complex control systems and give designers the flexibility to innovate. The CLC peripheral allows designers to create custom logic and interconnections specific to their application, reducing interrupt latency, saving code space and adding functionality. The COG peripheral is a powerful waveform generator that can generate complementary waveforms with fine control of key parameters, such as phase, dead-band, blanking, emergency shut-down states, and error-recovery strategies. It provides a cost-effective solution, saving both board space and component cost. The ZCD senses when high voltage AC signal crosses through ground, ideal for TRIAC control functions.

These new 8-bit PIC MCUs provide the capability for multiple independent, closed loop power channels and system management making these products appealing to various power supply, battery management, LED lighting, exterior/interior automotive lighting and general-purpose applications. Along with all these features, the family offers EUSART, I2C/SPI and eXtreme Low Power (XLP) Technology, which are all offered in small form-factor packages, ranging from 14- to 20-pin packages.

The PIC16(L)F1769 family is supported by Microchip’s standard suite of world-class development tools, including the MPLAB ICD 3 (part # DV164035, $199.95) and PICkit 3 (part # PG164130, $47.95) and MPLAB Code Configurator, which is a plug-in for Microchip’s freeMPLAB X IDE provides a graphical method to configure 8-bit systems and peripheral features, and gets you from concept to prototype in minutes by automatically generating efficient and easily modified C code for your application.

The PIC(L)F1764, PIC(L)F1765, PIC16(L)F1768, and PIC(L)F1769 are available now for sampling in 14- and 20-pins in PDIP, SOIC, SSOP, TSSOP, and QFN packages. Pricing for the family starts at $0.87 each, in 10,000-unit quantities.

Source: Microchip Technology

Fuzzy Logic for Embedded Microcontrollers

Fuzzy logic doesn’t necessarily need lots of horsepower. Many embedded applications that use more traditional control schemes can benefit from the use of fuzzy logic. Back in 1995, Jim Sibigtroth explained how to keep things simple and speedy.

In Circuit Cellar 56, Sibigtroth writes:

After describing basic fuzzy logic concepts, this article explains how to implement fuzzy-inference algorithms in a general-purpose embedded controller. The examples, written in assembly language, are for an MC68HC11, but the algorithms could be adapted for any general-purpose microcontroller. Code size is surprisingly small and execution time is fast enough to make fuzzy logic practical even in small embedded applications.

Perhaps because of its strange sounding name, fuzzy logic is still having trouble getting accepted as a serious engineering tool in the United States. In Japan and Europe, the story is quite different. The Japanese culture seems to respect ambiguity, so it is considered an honor to have a product which includes fuzzy logic. Japanese consumers understand fuzzy logic as intelligence similar to that used in human decisions.

In the US, engineers typically take the position that any control methodology without precise mathematical models is unworthy of serious consideration. In light of all the fuzzy success stories, this position is getting hard to defend.

I think the European attitude is more appropriate. It recognizes fuzzy logic as a helpful tool and uses it. They regard the difficulties of the nomenclature as a separate problem. Since the term “fuzzy” has negative connotations, they simply don’t advertise that products include fuzzy logic.

Figure l--Traditional sets are simply defined by their endpoints. Fuzzy sets add a second dimension to express fhe degree of truth (on the y-axis), which allows sets to be defined with gradual boundaries between false and true.

Figure l: Traditional sets are simply defined by their endpoints. Fuzzy sets add a second dimension to express the degree of truth (on the y-axis), which allows sets to be defined with gradual boundaries between false and true.

Curiously, the results produced by fuzzy-logic systems are as precise and repeatable as those produced by respected traditional methods. Instead of indicating lack of precision, the term “fuzzy” more accurately refers to the way real-world sets have gradual boundaries.

When we say “the temperature is warm,” there is not a specific temperature at which this expression goes from completely false to completely true. Instead, there is a gradual or fuzzy boundary, which requires a nonbinary description of truth. In fact, the fuzzy logic definition for a set contains more information than the conventional binary definition of a set.

In conventional systems, the range of an input parameter is broken into sets that begin and end at specific values. For example, a temperature range described as warm might include the temperatures 56-84°F (see Figure la). The trouble with this thinking is that the temperature 84.01”F suddenly stops being considered warm. This abrupt change is not the way humans think of concepts like “temperature is warm.”

Read the entire article, which appeared in Circuit Cellar 56, 1995.