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Stereo Spectrum Analyzer
by Richard Pierce (USA)
There are plenty of spectrum analyzers on the market. But you’ll likely need two of them to see both channels of a stereo signal. One solution is to build an analyzer to suit your needs. This design features two integrated channels of display, each with a 16 16 LED bar graph. p 16

Keywords: Spectrum analyzer, LED, FFT, MCP261, MCP6244, dsPIC33FJ64GP802, DMA, ADC

Control Shaft Encoders
by Keith Brown (Canada)
Searching for an ideal control shaft encoder can be a time-consuming task. This article details some workarounds to help determine which encoder is appropriate for an application. An interesting debounce and decode circuit is also presented. p. 26

Keywords: Encoder, shaft, rotary, PIC10F206, Gray code, incremental, quadrature, phase difference, detent, resolution, debounce, construction

Reprogrammable UAV Autopilot System (Part 2)
Testing and Results
by Mariano Lizarraga, Renwick Curry, and Gabriel Elkaim (USA)
In the first part of this series, you were introduced to the SLUGS reprogrammable UAV autopilot system. This article details the system’s software and flight test results. p. 36

Keywords: UAV, autopilot, guidance, navigation, control, dsPIC33, DSC, MATLAB, GPS, MAVLink, temperature, DSP-3000, gyro, attitude, aircraft

Getting Started with Microprogramming (Part 2)
A Look at the Meta-Assembler
by Thomas Mitchell (USA)
The first article in this series detailed the architecture, programmer model, instruction set, and general operation of a simple microprogrammed processor. Here you learn about real-world microprogramming and the meta-assembler. p. 46

Keywords: Microprogramming, Assembler, FPGA, WinTIM, testing, verification

Testing Platform
Construct a Custom Scope
by Jaime Garnica (USA)
The Scopey II is a handy oscilloscope and spectrum analyzer. In Oscilloscope mode, it acts as a basic oscilloscope with a sampling rate up to 750 ksps. In Spectrum Analyzer mode, a 256-point FFT is performed to obtain the spectrum of an input signal. p. 56

Keywords: Oscilloscope, spectrum analyzer, FFT, TLV2374, PGA, ADC, LCD, MCP6S21, dsPIC30F4011, LCD-00710

COLUMNS

THE CONSUMMATE ENGINEER

Functional Upset
by George Novacek (Canada)
Functional upset occurs when an embedded controller stops working as designed. To minimize the impact of such a problem, you should follow professional wiring practices and create system topologies in a thoughtful, systematic fashion. p. 14

Keywords: Functional upset, lightning, interference, system topology, suppression, EMC, EMI, wiring, layout, last good data, FADEC

LESSONS FROM THE TRENCHES

Design Development (Part 1)
Planning and Tools
by George Martin (USA)
You can read and write C code. The next step is to start building something. Follow these tips as you prepare to develop your next product. p. 64

Keywords: Design process, C, UML, tasks, schedule, Magic Draw

FROM THE BENCH

Error Checking
by Jeff Bachiochi (USA)
Data security isn’t a perk. It’s a requirement. This article covers the topics of error checking, checksums, and the cyclic redundancy check. Error checking matters. p. 68

Keywords: Error checking, checksum.cyclic redundancy check, CRC, UART, calculations, table