8-bit Microcontroller Features Compact 8-Pin Package

STMicroelectronics has introduced its new 8-bit STM8S001 microcontroller (MCU) in an economical SO-8 package. The STM8S001 has I2C, UART, and SPI interfaces, giving unusually versatile connectivity options. With a generous 8KB Flash memory, 1 KB RAM, 128-byte EEPROM, and 3-channel 10-bit ADC also on-chip, it delivers key features of ST’s STM8S003 MCU in a space-saving, low-pin-count device. Additional features include five en.STM8S_MCU_8_pin_package_N3970S_bigGPIOs, one 8-bit and two 16-bit timers, and an internal RC oscillator that allows flexible clock control from 128 kHz to 16 MHz. There is also a Single-Wire Interface Module (SWIM) for programming and debugging.

Fully specified from -40°C to 125°C and featuring the modern and efficient STM8 core operating at 16 MHz, the STM8S001 is well suited for industrial devices like smart sensors and lighting controls, as well as consumer products such as toys, small appliances, personal electronics, PC peripherals, battery chargers, and many others. The STM8S001 in 8-pin SO-8 is in production now, priced from $0.20 for orders of 1,000 pieces. A Discovery kit will be available in Q4 2017.

STMicroelectronics | www.st.com

Nissan Chooses Renesas Chips for Automatic-Parking Gear

Renesas Electronics has announced that its R-Car system-on-chip (SoC) for car infotainment and advanced driving assistant systems (ADAS) as well as its RH850 automotive control microcontroller have been adopted by Nissan for the ProPILOT Park, a full-fledged automated-parking system, of its new LEAF, Nissan’s new 100 percent electric vehicle.

The R-Car SoC adopted in the ProPILOT Park of the new Nissan LEAF recognizes spaces adequate for parking, verifies that there are no obstacles in the way, and handles 20170906-soc-mcu-automated-parkingthe role of issuing control commands for acceleration, braking, steering and shifting. The R-Car SoC includes Renesas’ exclusive parallel image processor (IMP) dedicated for image processing. The IMP takes the high-resolution images from the latest automotive CMOS digital cameras and performs high-speed, low-power signal processing. The RH850 MCU accepts the chassis control commands from the R-Car SoC and transmits these commands to the various electronic control units (ECUs) used. This enables the Nissan LEAF’s ProPILOT Park to achieve safe and reliable parking operation.

Based on the newly-launched Renesas autonomy, a new advanced driving assistance systems (ADAS) and automated driving platform, Renesas enables a safe, secure, and convenient driving experience by providing innovative solutions for next-generation car.

Renesas Electronics | www.renesas.com

Wi-Fi MCU Platform Update Targets Smart Home

Cypress Semiconductor has announced an updated version of its turnkey development platform for the IoT that simplifies the integration of wireless connectivity into smart home applications. The Wireless Internet Connectivity for Embedded Devices (WICED) Studio platform now adds iCloud remote access support for Wi-Fi-based accessories that support Apple HomeKit. Developers can leverage iCloud support in the WICED software Cypress WICED IoT Development Kit_0development kit (SDK) and Cypress’ CYW43907 Wi-Fi MCU to create hub-independent platforms that connect directly to Siri voice control and the Apple Home app remotely. Developers can access the WICED Studio platform, ecosystem and community at www.cypress.com/wicedcommunity.

Using Cypress’ WICED development platform and ultra-low power CYW20719 Bluetooth/BLE MCU, developers can integrate HomeKit support into products such as smart lighting devices, leverage Siri voice control and connect to the Apple Home app seamlessly. WICED Studio provides a single development environment for multiple wireless technologies, including Cypress’ world-class Wi-Fi, Bluetooth and combo solutions, with an easy-to-use application programming interface in the world’s most integrated and interoperable wireless SDK. The kit includes broadly deployed and rigorously tested Wi-Fi and Bluetooth protocol stacks, and it offers simplified application programming interfaces that free developers from needing to learn about complex wireless technologies. The SDK also supports Cypress’ high-performance 802.11ac Wi-Fi solutions that use high-speed transmissions to enable IoT devices with faster downloads and better range, as well as lower power consumption by quickly exploiting deep sleep modes.

The Cypress CYW43907 SoC integrates dual-band IEEE 802.11b/g/n Wi-Fi with a 320-MHz ARM Cortex-R4 RISC processor and 2 MB of SRAM to run applications and manage IoT protocols. The SoC’s power management unit simplifies power topologies and optimizing energy consumption. The WICED SDK provides code examples, tools and development support for the CYW43907.

 WICED Studio IoT Development Platform

The WICED platform supports a broad range of other popular cloud services and eliminates the need for developers to implement the various protocols to connect to them, reducing development time and costs. The WICED Studio SDK enables cloud connectivity in minutes with its robust libraries that uniquely integrate popular cloud services such as iCloud, Amazon Web Services, IBM Bluemix, Alibaba Cloud, and Microsoft Azure, along with services from private cloud partners and China’s Weibo social media platform.

In line with the IoT trend toward dual-mode connectivity, the kit supports Cypress’ Wi-Fi and Bluetooth combination solutions and its low-power Bluetooth and Bluetooth Low Energy (BLE) combination solutions. The SDK features a single installer package for multiple wireless technologies with an Eclipse-based Integrated Development Environment (IDE) that runs on multiple operating systems, including Windows, MacOS and Linux.

Cypress’ WICED Studio connectivity suite is microcontroller (MCU)-agnostic and provides ready support for a variety of third-party MCUs to address the needs of complex IoT applications. The platform also enables cost efficient solutions for simple IoT applications by integrating MCU functionality into the connectivity device. Wi-Fi and Bluetooth protocol stacks can run transparently on a host MCU or in embedded mode, allowing for flexible platform architectures with common firmware.

Cypress Semiconductor | www.cypress.com

Getting Started with PSoC MCUs (Part 3)

Data Conversion, Capacitive Sensing and More

In the previous parts of this series, Nishant laid the groundwork for getting up and running with the PSoC. Here he tackles the chip’s more complex features like Data Conversion and CapSense.

By Nishant Mittal
Systems Engineer, Cypress Semiconductor

In the previous two parts of this “Getting started with PSoC” series, I have hopefully provided you with a good base of knowledge about PSoC devices. Here, in this final part it’s time to get more in depth and discuss various data conversion protocols in PSoC and provide some design examples. I’ll also cover interfacing various peripherals with the Photo 1microcontroller. We’ll also get into how to transition from a bare silicon PSoC chip or PSoC development board to using the chip in your project.

Data conversion with PSoC

Data Conversion is an important block in any kind of instrumentation system or Internet of Things implementation. In fact, any application that uses sensors or interfaces to the external environment is an application in which Data Conversion is an integral part of the system. Although digital sensors are available today, the lower costs of analog sensors shouldn’t be overlooked.


PSoC Creator has a Data Conversion component that enables designers to code efficiently with less effort. The photo above shows the screenshot of the ADC (analog-to-digital conversion) component in PSoC Creator. The photo above also shows the configuration setting for ADC. First off, we need to set the Channel sampling rate (SPS). Second, we need to set the voltage reference which is necessary to do the comparison of analog signals. Here we use VDDA/2 or VDDA which is 5 V. You can select whether you For web Figure 1want a single-ended ADC or differential ADC by simply clicking the appropriate tab from the component configuration. Clock source needs to be chosen. If the source is chosen to be internal, the PLL from the internals of chip are used—otherwise you’d have to connect an external crystal to the controller using the development kit CY8CKIT-044. Other advanced settings are available for complex programs—but most of those aren’t needed in most intermediate applications.

Read the full article in the September 326 issue of Circuit Cellar

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Microchip Adds AVR and SAM MCUs to Programming Service

Microchip Technology , has expanded its custom programming service to include AVR and SAM microcontrollers (MCUs). Users can add their custom code to MCUs from more than 30 AVR and SAM families, along with nearly all PIC MCUs and memory devices, directly from the manufacturer via microchipDIRECT.  Microchip  provides an online custom programming service to all of its clients.

Microchip’s custom programming service is available to any client regardless of their order size and can be used throughout the development process. From a7be46ac521844589d6de789549e7c153very small runs to verify that the code is working, all the way up through full-scale production runs, this cost-effective programming service offers customers the flexibility to add their code to any order size, from one device to millions. Additionally, each first verification order is complimentary and includes three free samples programmed to each client’s exact specifications.

To get started, clients choose their part number on microchipDIRECT and then add their code and other configuration settings, shown on the intuitive online form, directly into the encrypted website. The MCUs will then be programmed directly by Microchip with no need to involve a third party programming or manufacturing facility, thus eliminating the risk of code exposure during the programming process.

In addition to custom programming services, microchipDIRECT also offers value-added services such as tape and reeling, labels, ink dotting and more. With the largest inventory of Microchip products in the industry, microchipDIRECT provides a full service channel for all purchasing needs. The mobile-optimized website also offers global support in ten languages, volume pricing, live service agents, numerous payment options and order notifications for customer convenience. For more information visit www.microchipdirect.com.

Custom programming directly from Microchip is available for nearly all PIC MCUs and more than 30 AVR and SAM families with additional device support rolling out over the next year. For more information about this custom programming service, visit: www.microchipdirect.com/avr-sam-programming.html

Microchip Technology | www.microchip.com

Time-Oriented Task Manager

…for 8-bit PIC Microcontrollers

For many new embedded applications, an 8-bit MCU is just right. Pedro
shows how to build a time-oriented task manager using Microchip’s PIC
16F628A 8-bit microcontroller.

By Pedro Bertoleti

Microcontrollers are everywhere. From a simple remote control to an advanced car embedded system, microcontrollers surround us all. But while an 8-bit microcontroller is a relatively simple device, the software on them can get more sophisticated as more functionality is added to embedded systems. One of the most interesting advances in software technique is managing tasks. That involves enabling a microcontroller to execute several scheduled tasks, ensuring periodic and precise time execution. Here, we will examine how to implement a time-oriented task manager for a simple microcontroller—in this case, a Microchip 8-bit PIC microcontroller.

A graphic representation of a time-oriented task manager and its tasks

A graphic representation of a time-oriented task manager and its tasks

A good place to start is to ask: What is a task? A task is a part of a software program that’s dedicated to do something exclusively. In other words, a task is a piece of software that can be implemented and executed as an independent software program. Take, for example, an embedded system that has to blink an LED, send something through the UART interface and check an input’s state. Each one of these activities can be defined as a task. In a general way, each function of an embedded system can be defined as a task. A time-oriented task manager is a piece of software that performs these three main activities:

  • Execute tasks periodically
  • Execute tasks in the amount of time specified for them
  • Ensure time-precision measurement for the execution of tasks

In terms of coding, the time-oriented task manager and the tasks are different parts of the same software program. ….

Read the full article in the September 326 issue of Circuit Cellar

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ST Deploys Low-Layer Software for All STM32 MCUs

STMicroelectronics has completed the introduction of its free Low-Layer Application Programming Interface (LL API) software to the STM32Cube software packages for all STM32 microcontrollers. The LL APIs enable expert developers to work within the convenient and easy-to-use STMCube environment, and optimize their code down to the register level using ST-validated software for faster time to market.


The combination of LL APIs and Hardware Abstraction Layer (HAL) software in all STM32Cube packages now gives developers complete flexibility when choosing how to control device peripherals. They can leverage the HAL’s ease of use and portability or use LL APIs to optimize performance, code footprint, and power consumption. Code examples tailored to run on the associated STM32 Nucleo board provide templates that simplify porting to other STM32 MCUs.

With features such as peripheral-initialization services that are functionally equivalent to STM32 Standard Peripheral Libraries (SPLs), the LL APIs present an easy migration path from the older SPLs to the simple but powerful STM32Cube ecosystem. Using the LL APIs can deliver superior performance, comparable to that of STM32Snippets direct-register-access code examples.

The LL APIs are MISRA-C 2004 compliant except where indicated, and have been checked using Grammatech CodeSonar for optimum code quality and reliability. An automatic-update mechanism inside STM32CubeMX keeps the LL APIs up to date with the latest releases. The STM32CubeMX tool automates the generation of peripheral-initialization code with LL APIs for STM32L0, STM32F0, STM32L4, and STM32F3 MCUs. Support for the remaining STM32 series will be added in the coming months. A written guide and an automated tool for the SPL-to-LL code migration are also available.

More information on STM32CubeMX is available at www.st.com/stm32cubefw

STMicroelectronics | www.st.com

Microchip Launched Two New MCU Families

Microchip Technology has made available its new SAM D5x and SAM E5x microcontroller (MCU) families. These new 32-bit MCU families offer extensive connectivity interfaces, high performance and robust hardware-based security for a wide variety of applications. The SAM D5/E5 MCUs combine the performance of an ARM Cortex-M4 processor with a Floating Point Unit (FPU). This combination offloads the Central Processing Unit (CPU), increasing system efficiency and enabling process-intensive applications on a low-power platform.


Running at up to 120 MHz, the D5x and E5x MCUs feature up to 1 MB of dual-panel Flash with Error Correction Code (ECC), easily enabling live updates with no interruption to the running system. Additionally, these families are available with up to 256 KB of SRAM with ECC, vital to mission-critical applications such as medical devices or server systems.

These new MCUs have multiple interfaces that provide design flexibility for even the most demanding connectivity needs. Both families include a Quad Serial Peripheral Interface (QSPI) with an Execute in Place (XIP) feature. This allows the system to use high-performance serial Flash memories, which are both small and inexpensive compared to traditional pin parallel Flash, for external memory needs.

The SAM D5/E5 devices also feature a Secure Digital Host Controller (SDHC) for data logging, a Peripheral Touch Controller (PTC) for capacitive touch capabilities and best-in-class active power performance (65 microA/MHz) for applications requiring power efficiency. Additionally, the SAM E5 family includes two CAN-FD ports and a 10/100 Mbps Ethernet Media Access Controller (MAC) with IEEE 1588 support, making it well-suited for industrial automation, connected home and other Internet of Things (IoT) applications.

Both the SAM D5x and E5x families contain comprehensive cryptographic hardware and software support, enabling developers to incorporate security measures at a design’s inception. Hardware-based security features include a Public Key Cryptographic Controller (PUKCC) supporting Elliptic Curve Cryptography (ECC) and RSA schemes as well as an Advanced Encryption Standard (AES) cipher and Secure Hash Algorithms (SHA).

The SAM E54 Xplained Pro Evaluation Kit is available to kick-start development. The kit incorporates an on-board debugger, as well as additional peripherals, to further ease the design process. All SAM D5x/E5x MCUs are supported by the Atmel Studio 7 Integrated Development Environment (IDE) as well as Atmel START, a free online tool to configure peripherals and software that accelerates development. SAM D5x and SAM E5x devices are available today in a variety of pin counts and package options in volume production quantities. Devices in the SAM D5/E5 series are available starting at $2.43 each in 10,000 unit quantities. The SAM E54 Xplained Pro Evaluation Kit is available for $84.99 each.

Microchip | www.microchip.com

Cypress MCUs Selected for Toyota Camry Instrument Cluster

Cypress Semiconductor has announced that global automotive supplier DENSO has selected Cypress’ Traveo automotive microcontroller (MCU) family and FL-S Serial NOR Flash memory family to drive the advanced graphics in its instrument cluster for the 2017 Toyota Camry. The DENSO instrument cluster uses Traveo devices that Cypress says were the industry’s first 3D-capable ARM Cortex-R5 cluster MCUs.

Denso Instrument Cluster

The FL-S memory in the cluster is based on Cypress’ proprietary MirrorBit NOR Flash process technology, which enables high density serial NOR Flash memory by storing two bits per cell. The DENSO instrument cluster has 4.2- and 7.0-inch screens capable of audio, video and navigation in the center display of the 2017 Toyota Camry.

Cypress works with the world’s top automotive companies to support automotive systems including Advanced Driver Assistance Systems (ADAS), 3-D graphics displays, wireless connectivity, full-featured touchscreens and superior body electronics. Cypress’ automotive portfolio includes the Traveo MCU family, power-management ICs (PMICs), PSoC programmable system-on-chip solutions, CapSense capacitive-sensing solutions, TrueTouch touchscreens, NOR flash, F-RAM and SRAM memories, and USB, Wi-Fi and Bluetooth connectivity solutions. The portfolio is backed by Cypress’ commitment to zero defects, excellent service and adherence to the most stringent industry standards, such as the ISO/TS 16949 quality management system, the Automotive Electronics Council (AEC) guidelines for ICs and the Production Part Approval Process (PPAP).

Cypress Semiconductor | www.cypress.com

Cypress and Arrow Team up for IoT Development Platform

Cypress Semiconductor and Arrow Electronics have announced a new development platform that enables engineers to quickly bring a broad range of connected IoT products to market.

The new Quicksilver kit features Cypress’ Wireless Connectivity for Embedded Devices (WICED) platform and incorporates the robust connectivity of the Cypress CYW43907 802.11n Wi-Fi microcontroller (MCU). The kit is slated for release in this  month (July 2017), and a second Quicksilver kit will deliver high-performance 802.11ac Wi-Fi enabling high-data-rate and media-rich experiences in the IoT in the fourth quarter of 2017.

According to Cypress, development customers are seeking to connect their products to the cloud for the first time to enable compelling IoT features, and they are also looking for fast time to market. The WICED-based Quicksilver kit provides them with the flexibility to build quickly now and streamline design enhancements later. Customers can quickly get to market with a certified module that provides turnkey cloud connectivity software and then migrate to cost or performance-driven production solutions while maintaining hardware and software compatibility.

The first Quicksilver kit will provide users with complete design capabilities to implement the WICED Studio SDK and features Arduino-compatible headers for expansion capability. The kit includes temperature, humidity and three-axis motion sensors to design a complete IoT edge device for a broad range of end markets, including factory automation, lighting, smart irrigation, home appliances and home automation.

New STM32L4 MCUs with On-Chip Digital Filter

STMicroelectronics’s ultra-low-power STM32L45x microcontrollers (the STM32L451, the STM32L452, and the STM32L462 lines) are supported by a development ecosystem based on the STM32Cube platform. The new microcontroller lines offer a variety of features and benefits:

  • Integrated Digital Filter for Sigma-Delta Modulators (DFSDM) enables advanced audio capabilities (e.g., noise cancellation or sound localization).
  • Up to 512 Kbyte on-chip Flash and 160 Kbyte SRAM provide generous code and data storage.
  • A True Random-Number Generator (TRNG) streamlines development of security-conscious applications
  • Smart analog peripherals include a 12-bit 5-Msps ADC, internal voltage reference, and ultra-low-power comparators.
  • Multiple timers, a motor-control channel, a temperature sensor, and a capacitive-sensing interface
  • Deliver high core performance and exceptional ultra-low-power efficiency
  • A 36-µA/MHz Active mode current enables a longer runtime on small batteries

The development ecosystem includes the STM32CubeMX initialization-code generator and STM32CubeL4 package comprising:

  • Middleware components
  • Nucleo-64 Board-Support Package (BSP)
  • Hardware Abstraction Layer (HAL)
  • Low-Layer APIs (LLAPIs)


The STM32CubeMX has a power-estimation wizard, as well as other wizards for managing clock signals and pin assignments. The affordable Nucleo-64 board, NUCLEO-L452RE, enables you to test ideas and build prototypes. It integrates the ST-LINK/V2 probe-free debugger/programmer and you can expand it via Arduino-compatible headers.
The devices are currently available in small form-factor packages from QFN-48 to LQFP-100, including a 3.36 mm × 3.66 mm WLCSP. Prices start from $2.77 in 1,000-piece quantities for the STM32L451CCU6 with 256-KB flash memory and 160-KB SRAM in QFN-48. The development boards start at $14 for the legacy-compatible Nucleo-64 board (NUCLEO-L452RE). The NUCLEO-L452RE-P board with external DC/DC converter will be available to distributors in June 2017.

STMicroelectronics | www.st.com

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

A Timely Look at RFID Technology

Most of us have had that annoying experience of setting off an alarm as we leave a store because one item in our bags has a still-active radio-frequency identification (RFID) tag. So it’s back to the cashier for some deactivation (or to security for some questioning).

Retailers love RFID, for obvious reasons. So do other industries and governments dealing with limiting building access; tracking goods, livestock and people; collecting highway tolls and public transit fares; checking passports; finding airport baggage; managing hospital drug inventory… The list goes on and on.

RFIDRFID is a big business, and it is anticipated to grow despite concerns about privacy issues. Market researcher IDTechEx recently estimated that the RFID market—including tags, readers, and software and services for RFID labels, fobs, cards, and other form factors—will hit $9.2 billion in 2014 and increase to $30.24 billion in 2024.

So it’s good timing for columnist Jeff Bachiochi’s series about passive RFID tagging. Part 1 appears in Circuit Cellar’s May issue and focuses on read-only tags and transponder circuitry. It also hints at Bachiochi’s unfolding RFID project.

Other May issue highlights include DIY project articles describing an MCU-based trapdoor lift system, a customizable approach to an ASCII interface for sending commands to a sensor tool and receiving data, and a solar-powered home automation controller that enables household-device management and cloud connectivity to log temperature, energy use, and other data.

In addition, our columnists explore low-power wireless data receivers, testing and analyzing old and new batteries in a personal collection, and designing data centers to participate in smart-grid power management.

If you are a female engineer in search of some inspiration, read our interview with embedded systems expert Elecia White. Also, find out why new technology means a bright future for LEDs in emissive microdisplays.

MCU-Based Experimental Glider with GPS Receiver

When Jens Altenburg found a design for a compass-controlled glider in a 1930s paperback, he was inspired to make his own self-controlled model aircraft (see Photo 1)

Photo 1: This is the cover of an old paperback with the description of the compass-controlled glider. The model aircraft had a so-called “canard” configuration―a very modern design concept. Some highly sophisticated fighter planes are based on the same principle. (Photo used with permission of Ravensburger.)

Photo 1: This is the cover of an old paperback with the description of the compass-controlled glider. The model aircraft had a so-called “canard” configuration―a very modern design concept. Some highly sophisticated fighter planes are based on the same principle. (Photo used with permission of Ravensburger.)

His excellent article about his high-altitude, low-cost (HALO) experimental glider appears in Circuit Cellar’s April issue. The MCU-based glider includes a micro-GPs receiver and sensors and can climb to a preprogrammed altitude and find its way back home to a given coordinate.

Altenburg, a professor at the University of Applied Sciences Bingen in Germany, added more than a few twists to the 80-year-old plan. An essential design tool was the Reflex-XTR flight simulation software he used to trim his 3-D glider plan and conduct simulated flights.

Jens also researched other early autopilots, including the one used by the Fiesler Fi 103R German V-1 flying bomb. Known as buzz bombs during World War II, these rough predecessors of the cruise missile were launched against London after D-Day. Fortunately, they were vulnerable to anti-aircraft fire, but their autopilots were nonetheless mechanical engineering masterpieces (see Figure 1)

“Equipped with a compass, a single-axis gyro, and a barometric pressure sensor, the Fiesler Fi 103R German V-1 flying bomb flew without additional control,” Altenburg says. “The compass monitored the flying direction in general, the barometer controlled the altitude, and the gyro responded to short-duration disturbances (e.g., wind gusts).”

Figure 1: These are the main components of the Fieseler Fi 103R German V-1 flying bomb. The flight controller was designed as a mechanical computer with a magnetic compass and barometric pressure sensor for input. Short-time disturbances were damped with the main gyro (gimbal mounted) and two auxiliary gyros (fixed in one axis). The “mechanical” computer was pneumatically powered. The propeller log on top of the bomb measured the distance to the target.

Figure 1: These are the main components of the Fieseler Fi 103R German V-1 flying bomb. The flight controller was designed as a mechanical computer with a magnetic compass and barometric pressure sensor for input. Short-time disturbances were damped with the main gyro (gimbal mounted) and two auxiliary gyros (fixed in one axis). The “mechanical” computer was pneumatically powered. The propeller log on top of the bomb measured the distance to the target.

Altenburg adapted some of the V-1’s ideas into the flight control system for his 21st century autopilot glider. “All the Fi 103R board system’s electromechanical components received an electronic counterpart,” he says. “I replaced the mechanical gyros, the barometer, and the magnetic compass with MEMS. But it’s 2014, so I extended the electronics with a telemetry system and a GPS sensor.” (See Figure 2)

Figure 2: This is the flight controller’s block structure. The main function blocks are GPS, CPU, and power. GPS data is processed as a control signal for the servomotor.

Figure 2: This is the flight controller’s block structure. The main function blocks are GPS, CPU, and power. GPS data is processed as a control signal for the servomotor.

His article includes a detailed description of his glider’s flight-controller hardware, including the following:

Highly sophisticated electronics are always more sensitive to noise, power loss, and so forth. As discussed in the first sections of this article, a glider can be controlled by only a magnetic compass, some coils, and a battery. What else had to be done?

I divided the electronic system into different boards. The main board contains only the CPU and the GPS sensor. I thought that would be sufficient for basic functions. The magnetic and pressure sensor can be connected in case of extra missions. The telemetry unit is also a separate PCB.

Figure 3 shows the main board. Power is provided by a CR2032 lithium coin-cell battery. Two low-dropout linear regulators support the hardware with 1.8 and 2.7 V. The 1.8-V line is only for the GPS sensor. The second power supply provides the CPU with a stable voltage. The 2.7 V is the lowest voltage for the CPU’s internal ADC.

It is extremely important for the entire system to save power. Consequently, the servomotor has a separate power switch (Q1). As long as rudder movement isn’t necessary, the servomotor is powered off. The servomotor’s gear has enough drag to hold the rudder position without electrical power. The servomotor’s control signal is exactly the same as usually needed. It has a 1.1-to-2.1-ms pulse time range with about a 20-ms period. Two connectors (JP9 and JP10) are available for the extension boards (compass and telemetry)..

I used an STMicroelectronics LSM303DLM, which is a sensor module with a three-axis magnetometer and three-axis accelerometer. The sensor is connected by an I2C bus. The Bosch Sensortec BMP085 pressure sensor uses the same bus.

For telemetry, I applied an AXSEM AX5043 IC, which is a complete, narrow-band transceiver for multiple standards. The IC has an excellent link budget, which is the difference between output power in Transmit mode and input sensitivity in Receive mode. The higher the budget, the longer the transmission distance.

The AX5043 is also optimized for battery-powered applications. For modest demands, a standard crystal (X1, 16-MHz) is used for clock generation. In case of higher requirements, a temperature-compensated crystal oscillator (TCXO) is recommended.

The main board’s hardware with a CPU and a GPS sensor is shown. A CR2032 lithium coin-cell battery supplies the power. Two regulators provide 1.8  and 2.7 V for the GPS and the CPU. The main outputs are the servomotor’s signal and power switch.

Figure 3: The main board’s hardware with a CPU and a GPS sensor is shown. A CR2032 lithium coin-cell battery supplies the power. Two regulators provide 1.8 and 2.7 V for the GPS and the CPU. The main outputs are the servomotor’s signal and power switch.

Altenburg’s article also walks readers through the mathematical calculations needed to provide longitude, latitude, and course data to support navigation and the CPU’s most important sensor— the u-blox Fastrax UC430 GPS. He also discusses his experience using the Renesas Electronics R5F100AA microcontroller to equip the prototype board. (Altenburg’s glider won honorable mention in the 2012 Renesas RL78 Green Energy Challenge, see Photos 2 and 3).

The full article is in the April issue, now available for download by members or single-issue purchase.

One of the final steps is mounting the servomotor for rudder control. Thin cords connect the servomotor horn and the rudder. Two metal springs balance mechanical tolerances.

Photo 2: One of the final steps is mounting the servomotor for rudder control. Thin cords connect the servomotor horn and the rudder. Two metal springs balance mechanical tolerances.

Photo 2: This is the well-equipped high-altitude low-cost (HALO) experimental glider.

Photo 3: This is the well-equipped high-altitude low-cost (HALO) experimental glider.

Member Profile: Scott Weber

Scott Weber

Scott Weber

Arlington, Texas, USA

Scott said he started his Circuit Cellar subscription late in the last century. He chose the magazine because it had the right mix of MCU programming and electronics.

He has always enjoyed mixing discrete electronic projects with MCUs. In the early 1980s, he built a MCU board based on an RCA CDP1802 with wirewrap and programmed it with eight switches and a load button.

Back in the 1990s, Scott purchased a Microchip Technology PICStart Plus. “I was thrilled at how powerful and comprehensive the chip and tools were compared to the i8085 and CDP1802 devices I tinkered with years before,” he said.

Scott said he recently treated himself to a brand-new Fluke 77-IV multimeter.

Scott is building devices that can communicate through USB to MS Windows programs. “I don’t have in mind any specific system to control, it is something to learn and have fun with,” he said. “This means learning not only an embedded USB software framework, but also Microsoft Windows device drivers.”

“Embedded devices are popping up everywhere—in places most people don’t even realize they are being used. It’s fun discovering where they are being applied. It is so much easier to change the microcode of an MCU or FPGA as the unit is coming off the assembly line than it is to rewire a complex circuit design,” Scott said.

“I also like Member Profile Joe Pfeiffer’s final comment in Circuit Cellar 276: Surface-mount and ASIC devices are making a ‘barrier to entry’ for the hobbyist. You can’t breadboard those things! I gotta learn a good way to make my own PCBs!”