Component: Fast Fourier Transform (FFT) (DSP)

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Revision as of 12:26, 24 February 2014 by BenR (talk | contribs) (→‎Examples)
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Author Matrix Ltd
Version 1.1
Category DSP


Image Fast Fourier Transform (FFT) component

Provides a way of converting a buffer full of time domain data into frequency domain data. The output of the FFT is a set of frequency bins which correspond to the frequencies present in the signal. The number of frequency bins is equal to half the input buffer size with each bin being responsible for a portion of the frequency up to 1/2 the nyquist.

Examples

FFT Example File

FC6 Icon.png FFT Example


Example takes 256 analogue readings using an ADC input and then passes the collection of 256 samples to the FFT function which produces 128 individual frequency banks which are then plotted from left to right on the graphical LCD.

FFT.jpg

Downloadable macro reference

ReadFrequencyBank

No additional information


Parameters

UINT BankIdx


Return value

BYTE


FFT

No additional information


Parameters

This macro has no parameters


Return value

This call does not return a value


Simulation macro reference

This component does not contain any simulation macros


Property reference

Buffer Manager

This property is of type Fixed list of ints and can be referenced with the variable name buffer_manager.

No additional information


Input

This property is of type Fixed list of ints and can be referenced with the variable name input_a.

No additional information


Output Real

This property is of type Fixed list of ints and can be referenced with the variable name output_c.

No additional information


Output Imaginary

This property is of type Fixed list of ints and can be referenced with the variable name output_i.

No additional information


Accuracy

This property is of type Fixed list of ints and can be referenced with the variable name FFT_accuracy.

No additional information


Bit Depth

This property is of type Fixed list of ints and can be referenced with the variable name bit_depth.

No additional information


Sample Rate

This property is of type Floating point and can be referenced with the variable name sample_rate.

No additional information


Nyquist Frequency

This property is of type Floating point and can be referenced with the variable name nyquist.

No additional information


Frequency Bin Count

This property is of type Signed integer and can be referenced with the variable name bin_count.

No additional information


Frequency Bin Size (Hz)

This property is of type Floating point and can be referenced with the variable name bin_size.

No additional information