70009 Parallax Inc, 70009 Datasheet - Page 53

• Manufacturer Part Number: 70009
• Description: BOOK UNDERSTANDING SIGNALS
• Manufacturer: Parallax Inc
• Type: Signal Analysisr

Specifications of 70009

• Style: Book
• Title: Understanding Signals
• Contents: Guide to Generate, View and Measure Wave Forms
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• Other names: 70009PAR

Fast Fourier Transformation with the DualSineWaves.bs2 Program
The OPTAscope’s Fast Fourier Transformation (FFT) function emulates a device called a
spectrum analyzer by displaying the sine wave frequencies contained by a signal. Fourier
analysis is used extensively by the radio communication industry to prevent people from
accidentally broadcasting signals on other channels. This type of analysis can also be
used to look at things like engine vibration, where certain frequencies of vibration can
indicate particular problems. FFT is a vast subject, but this exercise will give you a brief
introduction by analyzing the mixed signal generated in the previous Activity.
Figure 3-10:
Mixed Frequency
Signal
The two
component sine
waves can be
discerned with the
Vertical Bars
cursors.
The 2 kHz
component is
measured in the
top picture.
The 6 kHz
component is
measured in the
bottom picture.