28119 Parallax Inc, 28119 Datasheet - Page 53

• Manufacturer Part Number: 28119
• Description: KIT UNDERSTANDING SIGNALS
• Manufacturer: Parallax Inc

Specifications of 28119

• Lead Free Status: Contains lead
• Accessory Type: Oscilloscope
• Interface Type: USB
• For Use With/related Products: BASIC Stamp® 2 and Board of Education
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

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.