It is interesting to look back over what has caught the attention of our readers over the last year. Below are listed the top ten technical articles on the Microcontroller designline during 2011.
1. Building a power meter application with an 8-bit MCU In this product how-to article Radomir Kozub describes how to use Freescale’s 8-bit MC9S08LH64 to build an intelligent and accurate single-phase power metering design, while keeping a low cost bill of materials.
2. Understanding embedded-system-boot techniques Boot-up, the sequence of steps that a system performs between when you switch on power and load applications, is simple in theory but often complex in reality. The main job of a boot loader is to load the operating system, but software and hardware engineers view this process in different ways. Mohit Arora and Varun Jain of Freescale Semiconductor describe U-Boot (Universal Boot Loader), a powerful open-source tool that deserves consideration in Linux-based designs.
3. USB simplified - adding USB connectivity to applications with legacy serial connections Universal serial bus (USB) has become an enormous success in industrial and commercial applications as it continues to replace many legacy serial connections (i.e. RS-232, 485). However, says Pedro Pachuca of Silicon Labs, for embedded solution designers, a USB implementation requires expert knowledge of the USB protocol, exhaustive software development and significant design time. In addition, USB-based MCUs may not offer the right peripheral set required for an application, resulting in time-to-market delays, increased design complexity and added cost. He explainsthe relatively painless and economical alternative: using fixed-function USB bridge chips to add USB connectivity to any embedded MCU-based system that uses serial communications.
4. Ultra-low power microcontrollers for compact wireless devices Scott Hanson of Ambiq Micro Inc, describes design strategies for ultra-low power microcontrollers for use in various existing and emerging wireless applications. Emphasis is placed on practical techniques to reduce both active and standby mode power. Design examples draw from experience with the ARM Cortex-M3 core.
5. .NET micro framework for the STM32 Did you ever want to use C# and Visual Studio for programming a modern microcontroller? Swiss-based Oberon Microsystems Inc. has contributed its port of Microsoft's .NET Micro Framework (NETMF) to the open source community, under the same license as NETMF itself (Apache 2.0). It targets the STM32 microcontroller family, which is based on the ARM Cortex-M3 architecture.
6. It takes two to tango: Simplifying Linux/WinCE real-time applications development using 8- and 32-bit low-cost microcontrollers Seeing the terms 'Linux/WinCE' in the same sentence as '8-bit probably comes as a surprise to most people. As the title, 'It takes two to tango' suggests, 8-bit microcontroller units (MCUs) can actually make Linux and WinCE software application development easier. Eric Gregori of Freescale says trick is to divide and conquer the job. First, you have a high-performance microprocessor, such as a Freescale i.MX or Power Architecture host processor, which executes a powerful OS. Next, you have the real-time bare metal code execute on an 8- or 32-bit MCU. The overall system, while more complex, is actually easier for developing and maintaining software.
7. An introduction to wireless sensor network concepts The proliferation of 'smart' energy management applications and the abundance of inexpensive, standards-based wireless MCUs are stimulating the growth of wireless sensor/actuator networks (WSAN) across diverse markets, including home and building automation, telemedicine, and lighting. Joe Tillison of Avnet Electronics Marketing examines some of the basic concepts of wireless sensor networks and protocols, the essential elements comprising a wireless sensor, and some of the important design considerations for using them.
8. Self-adaptive MEMS vibration energy harvester targets low frequencies CEA-Leti researchers are developing an innovative energy-harvesting technology that collects vibrations from the environment and converts them into electricity to power a variety of sensors. Ghislain Despesse explains who Leti has chosen to focus on harvesting low-frequency vibrations with varying frequencies and amplitudes.
9. Selecting 8-bit MCUs: A practical guide Many devices may be available that will do the job, but tailoring the selection tightly to your particular needs can make for a much smoother ride in the long run says Steve Terry. Much of the same thinking applied to 8-bit microcontrollers can be applied to 16- and 32-bit devices; however, cost, size, capabilities, performance, feature integration, and a host of other upscaled attributes quickly make it increasingly difficult to generalize on approach and applicability.
10. Big.LITTLE processing with ARM Cortex-A15 & Cortex-A7 Peter Greenhalgh presents the rationale and design behind the first big.LITTLE system from ARM based on the high-performance Cortex-A15 processor, the energy efficient Cortex-A7 processor, the coherent CCI-400 interconnect and supporting IP.
David Patterson, known for his pioneering research that led to RAID, clusters and more, is part of a team at UC Berkeley that recently made its RISC-V processor architecture an open source hardware offering. We talk with Patterson and one of his colleagues behind the effort about the opportunities they see, what new kinds of designs they hope to enable and what it means for today’s commercial processor giants such as Intel, ARM and Imagination Technologies.