Emulating Legacy Interfaces

Photo 1 - The PC/104 specifications relate to small modules, which can be stacked one above the other.

Do It with Microcontrollers There’s a number of important legacy interface technologies—like ISA and PCI—that are no longer supported by the mainstream computing industry. In his article Wolfgang examines ways to use inexpensive microcontrollers to emulate the bus signals of … Continue reading

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Numeric Precision vs. DDS Calculations

PHOTO 1
A knockoff Arduino Nano controls a generic AD9850 direct digital synthesizer circuit, both plugged into standard 0.1 inch headers, with hand-wiring connections below the proto board. The SMA connector provides a mechanically rugged output from the board; the DDS frequencies don’t require its RF properties.

Using the full frequency resolution of a direct digital synthesizer chip outstrips the capabilities of floating point numbers. Ed takes a look at what’s needed for high-resolution frequency calibration and measurements. By Ed Nisley As you saw in my July … Continue reading

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Getting Started with PSoC MCUs (Part 3)

For web Figure 1

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 … Continue reading

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Time-Oriented Task Manager

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

…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 … Continue reading

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Breaking a Password with Power Analysis Attacks

Breaking a Password with Power Analysis Attacks

In his previous column, Colin showed how timing attacks could be used to break a password check. This article brings out a more advanced type of attack called a power analysis attack, which exploits small leaks about internal states of … Continue reading

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Digital Guitar Amplifier/Effects Processor

This is a block diagram of the audio signal flow through the guitar amplifier.

Part 2: Design and Construction In the first part of this series, Brian introduced the Teensy 3.2 MCU module. Now he presents a digital guitar amplifier/effects unit that he built around two Teensy modules. By Brian Millier In the first … Continue reading

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Find and Eliminate Ground Loops

FIGURE 4: Ground isolator for three-prong powered appliances

Everything had been fine with my home entertainment center—comprising a TV, surround-sound amplifier, an AM/FM tuner, a ROKU, and a CD/DVD/BlueRay player—until I connected my desktop PC, which stores many of my music and video files on one of its … Continue reading

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Robots with a Vision

In M1’s IR sensor array, each LED is
fired in turn and detected reflections are latched by
the 74HC259 into an eight-bit byte.

Machine chine vision is a field of electrical engineering that’s changing how we interact with our environment, as well as the ways by which machines communicate with each other. Circuit Cellar has been publishing articles on the subject since the … Continue reading

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Reliability and Failure Prediction: A New Take

Simulation results should be available in a two-phase post-processor for each simulation, providing broad input on the PCB’s behavior under the defined conditions.

HALT methodology has been a popular way to test harsh environment reliability. A new approach involves PCB design simulation for vibration and acceleration for deeper yet faster analyses. By Craig Armenti & Dave Wiens—Mentor Board Systems Division Many electronic products … Continue reading

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Power Analysis of a Software DES Encryption Routine

The EFF’s “Deep Crack” board could brute force a DES key in a matter of days. (Photo courtesy of Electronic Frontier Foundation)

This article continues the foray into breaking software security routines, now targeting a software implementation of DES. This builds on a previous example of breaking a hardware AES example. By Colin O’Flynn In the previous column, I broke a simple … Continue reading

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How-To Guide for Timing Analysis

Photo 1: I used Timing Diagrammer Pro for the timing analysis of the simplified digital circuit. Note that the gray areas on the waveform denote regions of uncertainty. The red areas show a timing violation.

Although many young engineers have been taught excellent circuit design techniques, most haven’t been schooled about the importance of timing analysis. What is timing analysis? Why is timing analysis important? How do you perform timing analysis? Philip Nowe’s Circuit Cellar … Continue reading

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Vintage Programming Languages

PHOTO 1: An online emulator for my old Apple II

For the last 30 years, C has been my programming language of choice. As you probably know, C was invented in the early 1970s by Dennis M. Ritchie for the first UNIX kernel and ran on a DEC PDP-11 computer. I … Continue reading

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Bipolar Transistor Biasing

Figure 1
This NPN bipolar junction transistor is wired in the common-emitter configuration, meaning its emitter is grounded. Two basic equations dictate its behavior.

Going back to the basics is never a bad idea. Many electronics engineers are fluent with complex systems—such as microcontrollers, embedded OSes, or FPGAs—but seem to have more difficulties with single transistors. What a shame! A transistor can be a … Continue reading

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3-D Object Segmentation for Robot Handling

Photo 1
The InMoov robot built at Portland State University’s robotics lab

A commercial humanoid service robot needs to have capabilities to perform human-like tasks. One such task for a robot in a medical scenario would be to provide medicine to a patient. The robot would need to detect the medicine bottle … Continue reading

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Reflections on Software Development

FIGURE 1: Simplified software design process documentation. Testing, verification and validation (V&V) and control documents are not shown.

Present-day equipment relies on increasingly complex software, creating ever-greater demand for software quality and security. The two attributes, while similar in their effects, are different. A quality software is not necessarily secure, while a secure software is not necessarily of … Continue reading

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