The Perfect PCB Prototype

Photo 3: Notice that D1 will not actually touch J2, as the PCB layout program’s silkscreen outline indicates.

Interested in constructing perfect PCB prototypes? Richard Haendel has the solution for you. In this article, he explains how five simple steps—print, mount, punch, fit, and evaluate—can save you a lot of time and money. The following article first appeared in Circuit Cellar 156. … Continue reading


Minimum Mass Waveform Capture

Photo 1—The only components added to the operating Atmel AT90S2313 circuit needed to allow for waveform sampling with less than 1-μs resolution at 1-V full scale are the capacitor and two resistors. Imagine how small the circuit will be using surface-mount components.

I can capture repetitive waveforms at 1 Msps using a microcontroller’s on-chip PWM and comparator. The impetus for developing this technique came from my own need to capture repetitive waveforms using the least expensive and lowest part count means possible. … Continue reading


Execute Open-Source Arduino Code in a PIC Microcontroller Using the MPLAB IDE

Exercise 1 prototype

The Arduino single-board computer is a de facto standard tool for developing microcomputer applications within the hobbyist and educational communities. It provides an open-source hardware (OSH) environment based on a simple microcontroller board, as well as an open-source (OS) development … Continue reading


Analog Filter Essentials

With a tool like the Analog Filter Wizard (Analog Devices), life is easy

Analog frequency-selective filters are useful for noise reduction, antialiasing before digitizing a signal, frequency response correction, and more. In this article, Circuit Cellar columnist Robert Lacoste explains the differences between filters and how to design them with computer-aided tools.   The following article by Robert Lacoste … Continue reading


The Internet of Things: Cell Modem Certification

Japenga CC305

In the multipart article series, “The Internet of Things,” Bob Japenga details how to connect simple devices wirelessly to the Internet.  This month, he covers at the requirements for, the cost of, and some of the problems with cell modem … Continue reading


An Introduction to Verilog

Figure 1

If you are new to programming FPGAs and CPLDs or looking for a new design language, Kareem Matariyeh has the solution for you. In this article, he introduces you to Verilog. Although the hardware description language has been used in the … Continue reading


Build a Hand-Held Microcontroller-Based Scoring Device

A design-for-manufacturing approach was taken for
the construction of the aluminum-chassis prototype. The main
two-sided PCB has ample room for parts, mainly because of
the housing size needed to fit the AAA battery pack and LCD

The QuizWiz is an innovative hand-held device that teachers can use to score multiple choice tests. It’s unlikely that you’ll need such a device, but you’ll surely learn a lot from Paul Kiedrowski’s description of the design process. He covers … Continue reading


Build a Three-in-One Measurement System

Hand-soldering a package this size
is tough work. The signal-generator
filter has bulky coils. In contrast, the
MSP430F149’s PQFP64 is tiny.

No home electronics lab is complete without a signal generator, logic analyzer, and digital oscilloscope. But why purchase the measurement devices separately, when you can build one system that houses all three? The process is easier than you’d expect. Salvador Perdomo writes: I’ve built … Continue reading


Software-Only Hardware Simulation

Figure 1: There is a parallel between the embedded target and host environment. Equivalent entities are shown on the same level.

Simulating embedded hardware in a Windows environment can significantly reduce development time. In this article, Michael Melkonian provides techniques for the software-only simulation of embedded hardware. He presents a simple example of an RTOS-less embedded system that uses memory-mapped I/O … Continue reading


Power Over Ethernet Solutions

The D-Link DWL-P50 is a ready-togo
module. Ethernet in, Ethernet out,
and a choice between 12- and 5-VDC

Powering devices over Ethernet cabling seems easy, but there’s more to it than meets the eye. In this article, Eddie Insam explains how it all works. So you’ve designed a brand new Ethernet-based device. Perhaps it’s a clock, a weather … Continue reading


IoT Project: DIY, Net-Connected Wireless Water Heater

Serving up the current temperature involves
several computers, a Wi-Fi access point, and the
DPAC Airborne module.

Some people like to remotely start their cars when it’s cold outside. Dan Beadle took this idea one step further by Internet-enabling his mountainside retreat’s hydronics system. The innovative design enables him to warm the house well in advance of his arrival. … Continue reading


A Real-World Look at Lighting


Living on a granite hill during a thunderstorm gave Circuit Cellar founder Steve Ciarcia new respect for Mother Nature. In a classic 1998 article, Steve described how he worked with Circuit Cellar columnist Jeff Bachiochi on a solution to automatically … Continue reading


Wireless Remote Control of the AVMux


In 1994, Circuit Cellar’s founder, Steve Ciarcia, asked: “What good is having ultimate control over your virtual audio/video environment if you have to get out of your chair to change the setup?” Great question. His answer was even better: “Outfit … Continue reading