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Sampling: What Nyquist Didn't Say, and What to Do About It

The Nyquist Theorem is useful, but often misused when engineers establish sampling rates or design anti-aliasing filters. This article explains how sampling affects a signal, and how to use this information to design a sampling system with known performance.

PID without a PhD: A Simple Software Controller Design Method

While many control problems require a considerable amount of analysis and design, and some even require sweat and tears, many control problems can be solved with simple PID techniques. This article outlines how to write software to implement a PID controller, how to tune it, and gives you an idea of when to go to an expert.

Controlling Motors in the Presence of Friction and Backlash

Two of the most prevalent issues in controlling moving mechanisms are friction and backlash. These effects are present in nearly every mechanism that one may wish to control, yet methods for controlling them are not always obvious. This article explains friction and backlash effects, why they are a source of problems in motion system design, how a control system designer can predict their effects and how to mitigate those effects.

Z Transforms for the Embedded System Engineer

The z transform is an essential part of a structured control system design. This paper describes the basics of using the z transform to develop control systems, using the sort of math that is familiar to the accomplished embedded system designer.

Measuring Frequency Response

Structured control system design is all well and good, but what if you need to control something that didn't come with a description? Here's how to measure a systems characteristics in a way that will be directly usable in designing a controller.

Sigma-delta techniques extend DAC resolution

Often we are called upon to implement controllers or other systems with insufficient output resolution. This article shows how to implement simple sigma-delta modulators to extend the resolution of a digital to analog converter.

A DGPS/Radiobeacon Receiver using MSK

My master's thesis, but still occasionally useful. Describes the design and construction of a receiver that uses Minimum Shift Keying.

Using Block Diagrams in Control System Design

A description of block diagrams as used in control systems and signal processing texts, how to read them and how to manipulate them.

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