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Power loss？ No problem. Jeff‘s PIC16F87-based SPI power alarm peripheral circuit will keep you on top of things. This simple design will be a useful addition to a variety of applications，particularly those in the healthcare industry. The way most folks can tell when they‘ve lost power at home is when they see "12：00" flashing on their appliances. You may not have noticed， but some high-end models have a back-up supply that keeps the clock ticking during power outages. If you have such a mo...

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Part 2: Installation and Performance Last time， I described the planning and design phase of our off-the-grid solar system in Silver City， NM. This month， I will cover the installation process and explain how the system operates. All the mounting， wiring， and enclosures had to comply with the latest National Electrical Code （NEC） and any local variations. The code is there for a purpose. There may be variation in the details with your local installer or inspector， but approaching them in...

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Part 1: Planning And Design My wife and I are getting to the age at which we are looking for a place to retire. We live in Connecticut and have heard lots of stories about friends who sold their homes and left the state to retire only to regret the decision. So， our plan has been to find an area that we would consider for retirement and try it out by living there on a part-time basis. Well， to make a long story short， we ended up near Silver City， New Mexico， with a nice plot of land suitab...

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An Easy-to-Use Digital Signal Processing Platform Are you ready to venture into the world of digital signal processing effects？ This article is the perfect introduction. Kit describes a high-quality DSP platform and presents sample code. Almost every electric guitar player，from Jimmy Page to your next-door neighbor， uses an effects processor on his guitar. While there are a staggering number of effects used by guitarists and a nearly infinite number of ways to tweak them， a guitarist‘s tone...

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The Soft-Core Concept, FPGAs, And You Question： Does a "soft-core" make sense for your current application？ Tom covers the history of the soft-core technology and introduces the ARM Cortex-M1 soft-core and the FPGA chips it runs on. As you‘ll see， this solution from Actel and ARM makes the softcore concept more viable than ever for new applications. Question： You see an engineer staring at the screen and scratching their head. How can you tell if they‘re designing hardware or software？Ans...

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It‘s time to get rid of the wires between your sensors， slave devices， and the microcontrollers they serve. Fred shows you how to move data wirelessly with MaxStream's XBee modules. Uncomplicated wireless technology is at your fingertips. It doesn‘t get any better than this. Do you ever think about what‘s going on in the bowels of a conversation between your PC's USB port and the new hi-tech gadget you just plugged in？ Have you ever seriously thought about what‘s going on in that Ethernet...

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A Lighting System That Responds to Audio Stimuli With a Luminary Micro LM3S828， this group of designers built an interactive coffee table that responds to audio stimuli and produces flashy visual effects. The design-which features 96 tricolor LEDs， five custom circuit boards， and four electret microphones-can generate a single color display or exciting lighting effects. Our Shock-N-Awe table is capable of responding to audio stimuli by producing visuals that will， as we like to say in a worl...

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To compete with the rest of the 32-bit market， Microchip Technology designed its 32-bit offering around the MIPS architecture. The PIC32 combines Microchip‘s in-house MCU know-how with MIPS Technology's extensive IP， software， and tool library. Expect to see PIC32s for a long time to come. Thanks to the popularity of their venerable PIC chips and the robust 8/16-bit MCU market， Microchip Technology remains one of the world‘s top MCU suppliers. There is no doubt that the number of "sockets"...

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Many electronic devices are enhanced by crystals， but do you know why？ Robert explains why there are usually small capacitors around a crystal， the difference between "series" and "parallel" crystals， and more. Welcome to the Darker Side. I still consider myself reasonably young， but I remember when my dad bought one of the first inexpensive electronic watches. The display was made of seven-segment red LEDs， so I had to press a button to read it. Although the batteries drained after a coup...

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A Potentiometer with No Moving Parts Tired of replacing your mechanical parts？ Jeff has the solution：eliminate them. His design provides user input and a digital potentiometer for resistance or voltage output. Living in a material world has its benefits and drawbacks. You can either choose to become wrapped up in possessions with a possibility of becoming a King Midas or you can use technology to improve your life and those who share this neighborhood we call Earth. When I see the imbalance of...

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A Look Into The C Compiler Guess what happened after George recently made a few simple changes to a product for a customer and then recompiled the code？ Compiler errors！ In this column， he describes how he addressed the problem. While I was reading an article recently， the author wrote that he was using assembly language so he would have more control over the code. I thought this wasn‘t true. The C language should give you all of the control over the generated code you would ever want. A sh...

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Need a refresher on direct digital synthesis？ Robert brings you up to speed by covering DDS theory， a few chip-based solutions， and some firmware implementations. Welcome to the Darker Side. If you are a regular reader， you probably remember my December 2007 article about using a phase-locked loop （PLL）to generate precise and stable frequencies（"Are You Locked？： A PLL Primer，" Circuit Cellar 209）。 I also briefly introduced another interesting concept： the direct digital synthesizer，...

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Tom is a proponent of the 32-bit MCU revolution. This month， he covers several respectable 32-bit chips that deliver performance at a reasonable price. Exciting new applications are on your horizon. Long-time readers have heard me tell the story of the IC company executive who tried to convince me that the 8-bit market was "dead." The kicker is that he made that statement 25 years （and many billions of 8-bit MCUs） ago. Indeed， as far as I‘m concerned the 8-bit market will still be going str...

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It‘s time to get rid of the wires between your sensors， slave devices， and the microcontrollers they serve. Fred shows you how to move data wirelessly with MaxStream's XBee modules. Uncomplicated wireless technology is at your fingertips. It doesn‘t get any better than this. Do you ever think about what‘s going on in the bowels of a conversation between your PC's USB port and the new hi-tech gadget you just plugged in？ Have you ever seriously thought about what‘s going on in that Ethernet...

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ESC Delivers the Goods It‘s been a great year for embedded systems designers.You have plenty of new technologies and design options to consider. This month， Tom showcases the best and brightest on display at the 2008 Embedded Systems Conference in San Jose. This year‘s Embedded Systems Conference （ESC） in San Jose， CA，marked the twentieth year of the affair. Of course， embedded applications go back more than 20 years，indeed all the way back to the dawn of silicon. Nevertheless， ESC has...

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