David A. Ward

David's Articles

Product Review: The Digilent NEXYS3 Spartan-6 FPGA Board
February 2012
If you are interested in learning more about FPGAs (field programmable gate arrays) or implementing FPGA designs, Digilent ([url=http://www.digilent]http://www.digilent[/url] inc.com) has several FPGA boards available.

Getting Started With FPGAs — Part 2
October 2011
For this last part, a more complex and useful digital design using the Basys2 FPGA trainer will be demonstrated.

Getting Started With FPGAs — Part 1
September 2011
FPGAs are ICs found in some of the latest electronics products. This two-part series begins with a quick introduction to field programmable gate arrays to get you started experimenting with them.

CPLDs — Part 5: A CPLD Project
July 2011
For the last installment of this series, we incorporate a CPLD to control a mobile robotics platform.

CPLDs — Part 4: HDL Programming
June 2011
Now that you have a better idea of what a CPLD is and what it can do, it’s time to introduce and begin using HDL (hardware description language).

CPLDs — Part 3: Simulating a Digital Design
May 2011
This installment shows you how to simulate your digital logic design in Xilinx Isim.

CPLDs — Part 2: Graphical Programming of a CPLD
April 2011
We’ll get right into some CPLD programming and look at breadboarding and testing, as well.

CPLDs — Part 1: An Introduction
March 2011
Anyone involved with digital electronics should become familiar with complex programmable logic devices. This tutorial will take you through the paces, culminating with a demonstration of how to incorporate a CPLD to control a mobile robotics platform.

Computer Control And Data Acquisition: Part 5
July 2009
Building a Thermal Cycling System.

Computer Control And Data Acquisition
June 2009
Part 4: Working with analog signals.

An Introduction to Pneumatic Sytems | Part 1
January 2009
If you’re looking for a way to add muscle to your robots, then as Bob Dylan would say, the answer may be may be blowin' in the wind in the form of compressed air and pneumatic controls. I have wanted to incorporate pneumatics into some of my personal projects and (as an instructor) into my industrial control systems course for some time now, but wasn't sure where to begin. Pneumatic trainers are available for classroom instruction, but the ones I have checked into cost anywhere from $3,500 ...

An Introduction to Pneumatic Sytems | Part 2
February 2009
Now that the basic pneumatic system is operating manually, let's add some electronics to control it. If we add an electromechanical relay and two limit switches, we can make the piston travel back and forth continuously; check out the electrical schematic in Figure 1. The limit switches being used are momentary SPDT miniature switches (Photo 1) and the electromechanical relay is a DPDT 24 VDC coil relay with a socket (see Photo 2). By adding electrical limit switches at the fully retracted ...

Computer Control and Data Acquisition: Part 1
March 2009
An Introduction to National Instruments LabVIEW Software.

Computer Control and Data Acquisition: Part 2
April 2009
Part 2: An Introduction to National Instruments USB-6008 Data Acquisition Hardware. Part 1 introduced National Instruments LabVIEW software and had the reader build a very simple VI (virtual instrument). This article will introduce National Instrument’s most affordable computer interfacing hardware — the USB-6008(9) data acquisition units — and show how to use the digital features of the units...

Computer Control and Data Acquisition: Part 3
May 2009
From the previous two articles, you learned how to output and input digital signals using National Instruments LabVIEW software and their USB-6008(9) hardware. However, the signals have only been in the TTL range of voltages (0V and +5V) and with fairly low current levels, 8.5 mA maximum per digital terminal. In the real world outside of the PC and the USB-6008(9) units, voltage and current levels are typically much higher and also include AC signals. This article will demonstrate some of ...