FFT (FFT.h)

The Arduino FFT library is a fast implementation of a standard FFT algorithm which operates on only real data. It can give you up to 256 frequency bins at 16b depth, at a minimum of ~7ms update rate. It is adjustable from 16 to 256 bins, and has several output methods to suit various needs. It can be set to 16b linear, 8b linear, 8b logarithmic, or 8b octave output. All of these different modes are detailed in the read_me file (inside the FFT library folder). Since it takes in 16b, fixed point numbers, it has a noise floor of around -72dB in the low frequencies, and -76dB in the high frequencies. When using the onboard ADC, the ADC's noise floor is on the same order as the FFT's noise floor, giving somewhere between a 9b and 10b SNR (-55dB).

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Examples

2017-11-02 Pravin Kokane

I am getting below error could you please help in this regard
Arduino: 1.8.5 (Windows 10), Board: "Arduino/Genuino Mega or Mega 2560, ATmega2560 (Mega 2560)"
In file included from C:\Program Files (x86)\Arduino\libraries\FFT\examples\fft_adc\fft_adc.pde:14:0:
C:\Program Files (x86)\Arduino\libraries\FFT/FFT.h:74:10: error: 'prog_int16_t' does not name a type
PROGMEM prog_int16_t _wk_constants[] = {
^
In file included from C:\Program Files (x86)\Arduino\libraries\FFT\examples\fft_adc\fft_adc.pde:14:0:
C:\Program Files (x86)\Arduino\libraries\FFT/FFT.h:89:12: error: 'prog_uint8_t' does not name a type
PROGMEM prog_uint8_t _reorder_table[] = {
^
In file included from C:\Program Files (x86)\Arduino\libraries\FFT\examples\fft_adc\fft_adc.pde:14:0:
C:\Program Files (x86)\Arduino\libraries\FFT/FFT.h:105:12: error: 'prog_uint8_t' does not name a type
PROGMEM prog_uint8_t _log_table[] = {
^
In file included from C:\Program Files (x86)\Arduino\libraries\FFT\examples\fft_adc\fft_adc.pde:14:0:
C:\Program Files (x86)\Arduino\libraries\FFT/FFT.h:133:12: error: 'prog_int16_t' does not name a type
PROGMEM prog_int16_t _window_func[] = {
^
exit status 1
Error compiling for board Arduino/Genuino Mega or Mega 2560.
This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.
2015-11-19 codebender

This library and its examples were tested on 2016-06-11 with common Arduino boards. For more detailed information about the test results, please look at each example's comments.