On Design
Dial-Up Modems Still Ring a Bell
October 25, 2007 10:41 am | by Jon Titus, Senior Technical Editor | Articles | CommentsYears ago I ditched my 9600 bps modem, but I still rely on dial-up modems. Those modems exist in automated teller machines, gasoline pumps, traffic controllers, medical instruments, security systems, point-of-sale (POS) equipment, and other devices. According to several sources, dial-up modems still provide the largest number of access points to the Internet. Fortunately, several OEM vendors supply dial-up modem modules that offer drop-in communications in small packages.
Compiler Cuts Code in Half
October 23, 2007 11:01 am | Atmel Corporation | Product Releases | CommentsHi-Tech Software has announced a new compilation technology that generates object code based on call- and pointer-reference graphs derived from all the modules in an embedded program. The new technology, called Omniscient Code Generation (OCG), overcomes problems in conventional compilers that can miss inconsistent calling conventions, variable declarations and redundant code because they compile each module independently and separately. OCG results in more easily ported code that is nearly 50 percent more dense than code from competing compilers.
Get a Hardware Head Start
September 25, 2007 12:30 pm | by Get a Hardware Head Start | Articles | CommentsThe Connect ME JumpStart development kit from Digi International includes a Comment ME module and development board. Software provides a 90-day evaluation version of Microsoft's Visual Studio 2005 Professional and the Microsoft .NET Micro Framework SDK plug-in for Visual Studio. This kit provides a quick and easy way to investigate .NET Micro Framework and its related tools and to build an embedded product that requires an Ethernet connection.
Dot NET: Embedded Development for the Rest of Us
September 17, 2007 12:52 pm | by John Leier, Digi International | Articles | CommentsOn a recent flight I talked with a software-engineering manager about the challenges of finding good embedded-system developers. She told me she has a team of 12 developers, but only three had proficiency with drivers, board-support packages, and boot-loaders. The other nine -- all good application developers -- lacked low-level coding experience. I asked if she had heard of the Microsoft .NET Micro Framework.
8-Bit MCUs Keep Going Strong
August 29, 2007 5:22 am | by Jon Titus, Senior Technical Editor | Articles | Comments"Cost still rules applications," said Ross Bannatyne, Marketing Director at Silicon Laboratories, a supplier of 8051-based MCUs. "If 8-bit MCUs solve problems, why use more expensive 32-bit chips?" Newer 8051 derivatives, for example, execute 100 MIPS and on-chip multiply-accumulate accelerators let them handle signal-processing tasks. According to Bannatyne, some engineers might not realize 32-bit MCUs can incur code penalties. "They might assume an algorithm that requires 16 KB in an 8-bit MCU also needs 16 KB in a 32-bit processor. Often the code takes more memory in the 32-bit processor, often much more."
Kits for Kids
July 30, 2007 7:57 am | by Jon Titus, Senior Technical Editor | Articles | CommentsAs a youngster I enjoyed wiring up circuits with knife switches, lamps, buzzers and large dry cells. While in high school I made frequent trips to surplus-electronics stores in New York City and ordered components from mail-order supply houses. My projects included a 4-bit binary adder -- built from switches and relays -- and a tic-tac-toe machine. I also built my share of kits from Knight, Eico and Heath. My friend Bill Kuhn designed and built relay-logic learning machines.
Serial Buses Free I/O Pins
June 25, 2007 11:14 am | by Jon Titus | Articles | CommentsMore times than designers might like to admit, they wish for just one more I/O pin on a microcontroller. Three chip-to-chip serial buses can help overcome I/O pin limits. The following information provides a quick overview and points you to sources of more information.
An Introduction to RapidIO
June 4, 2007 7:07 am | by Tom Cox, Executive Director, RapidIO Trade Association | Articles | CommentsYears ago, designers involved with high-performance computer systems realized the parallel-bus structures found in most computers had run their course. New computer systems, such as those based on VME64x, move data across switched-fabric networks. Unlike a bus that connects all boards to all signals, a switched-fabric network routes communications through switches. Thus communications can take one of several high-speed paths and no longer create a bus bottleneck. In this context, "fabric" implies a point-to-point network that designers can "scale" to accommodate thousands of nodes. But a fabric does not imply the use of a specific hardware or software architecture.
Timeless Sensor Sources
May 2, 2007 5:12 am | by Jon Titus, Senior Technical Editor | Articles | CommentsOver the years, I have accumulated articles, books and application notes that relate to sensors and measurement techniques. In this column – a change of pace from ECN's usual Embedded Systems column format – I share many of those resources with you. Some of this information may seem "old," so you may not know about these sources or an Internet search will not find them.
Rotary Encoders take the Shaft
April 2, 2007 6:46 am | Product Releases | CommentsRotary shaft encoders convert an angular position into an electrical quantity or digital code that a computer can use to determine the location of a connected object. Encoders come in two varieties - absolute and incremental - and most rely on optoelectric or magnetic sensors. Both types divide a 360° rotation into hundred or thousands of equally spaced units, or counts. Thus, engineers can choose an angular resolution that meets their needs. An absolute encoder indicates a specific position within the shaft's 360° rotation and an incremental position indicates the change in rotation from one position to another. (You also can derive velocity and acceleration from encoder signals.)
