Mini projet de FFT
Dependencies: mbed Grove_LCD_RGB_Backlight UIT_FFT_Real
main.cpp@2:525fb567d140, 2019-05-31 (annotated)
- Committer:
- AxelBoujon
- Date:
- Fri May 31 11:30:06 2019 +0000
- Revision:
- 2:525fb567d140
- Parent:
- 1:a806f3aacf1f
Projet de FFT
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
SBACCARI | 0:c7f159ed0bc3 | 1 | #include "mbed.h" |
SBACCARI | 0:c7f159ed0bc3 | 2 | #include "Grove_LCD_RGB_Backlight.h" |
SBACCARI | 0:c7f159ed0bc3 | 3 | #include "fftReal.hpp" |
SBACCARI | 0:c7f159ed0bc3 | 4 | |
AxelBoujon | 2:525fb567d140 | 5 | #define Nb_echantillons 256 |
AxelBoujon | 2:525fb567d140 | 6 | |
AxelBoujon | 2:525fb567d140 | 7 | //Elements |
SBACCARI | 0:c7f159ed0bc3 | 8 | Grove_LCD_RGB_Backlight ecran(P0_27, P0_28); |
SBACCARI | 0:c7f159ed0bc3 | 9 | AnalogIn micro(A1); |
SBACCARI | 0:c7f159ed0bc3 | 10 | |
AxelBoujon | 2:525fb567d140 | 11 | //Variables |
AxelBoujon | 2:525fb567d140 | 12 | Ticker echantillonage; |
SBACCARI | 0:c7f159ed0bc3 | 13 | int sampling_freq = 44000; |
AxelBoujon | 2:525fb567d140 | 14 | float echantillons[Nb_echantillons*2]; |
SBACCARI | 0:c7f159ed0bc3 | 15 | int i = 0; |
AxelBoujon | 2:525fb567d140 | 16 | Mikami::Complex fft_bins[Nb_echantillons]; |
AxelBoujon | 2:525fb567d140 | 17 | Mikami::FftReal fft((int16_t)Nb_echantillons); |
SBACCARI | 0:c7f159ed0bc3 | 18 | |
SBACCARI | 0:c7f159ed0bc3 | 19 | void sampling_interrup() |
SBACCARI | 0:c7f159ed0bc3 | 20 | { |
AxelBoujon | 2:525fb567d140 | 21 | echantillons[i] = 1024*micro.read(); // 1024 : ADC of the sound sensor |
SBACCARI | 0:c7f159ed0bc3 | 22 | i++; |
AxelBoujon | 2:525fb567d140 | 23 | if (i >= Nb_echantillons*2) { |
AxelBoujon | 2:525fb567d140 | 24 | echantillonage.detach(); |
SBACCARI | 0:c7f159ed0bc3 | 25 | } |
SBACCARI | 0:c7f159ed0bc3 | 26 | } |
SBACCARI | 0:c7f159ed0bc3 | 27 | |
SBACCARI | 0:c7f159ed0bc3 | 28 | void samplingBegin() |
SBACCARI | 0:c7f159ed0bc3 | 29 | { |
SBACCARI | 0:c7f159ed0bc3 | 30 | // Reset sample buffer position and start callback at the sampling frequency |
SBACCARI | 0:c7f159ed0bc3 | 31 | i = 0; |
AxelBoujon | 2:525fb567d140 | 32 | echantillonage.attach_us(&sampling_interrup, 1000000/sampling_freq); |
SBACCARI | 0:c7f159ed0bc3 | 33 | } |
SBACCARI | 0:c7f159ed0bc3 | 34 | |
SBACCARI | 0:c7f159ed0bc3 | 35 | bool samplingDone() |
SBACCARI | 0:c7f159ed0bc3 | 36 | { |
AxelBoujon | 2:525fb567d140 | 37 | return i >= Nb_echantillons*2; |
SBACCARI | 0:c7f159ed0bc3 | 38 | } |
SBACCARI | 0:c7f159ed0bc3 | 39 | |
AxelBoujon | 2:525fb567d140 | 40 | void FFT(){ |
AxelBoujon | 2:525fb567d140 | 41 | char str[20]; |
AxelBoujon | 2:525fb567d140 | 42 | // max 1 is set to the second FFT bin, because the first bin has the DC componenet of the signal. |
AxelBoujon | 2:525fb567d140 | 43 | int MAX = 2; |
AxelBoujon | 2:525fb567d140 | 44 | //int max2 = 3; |
AxelBoujon | 2:525fb567d140 | 45 | float val = 0; |
AxelBoujon | 2:525fb567d140 | 46 | /*ecran.locate(0, 0); |
AxelBoujon | 2:525fb567d140 | 47 | sprintf(str,"Sampling done"); |
AxelBoujon | 2:525fb567d140 | 48 | ecran.print(str); |
AxelBoujon | 2:525fb567d140 | 49 | wait(1);*/ |
AxelBoujon | 2:525fb567d140 | 50 | fft.Execute(echantillons,fft_bins); |
AxelBoujon | 2:525fb567d140 | 51 | wait(0.5); |
AxelBoujon | 2:525fb567d140 | 52 | |
AxelBoujon | 2:525fb567d140 | 53 | /*ecran.clear(); |
AxelBoujon | 2:525fb567d140 | 54 | sprintf(str,"FFT Done"); |
AxelBoujon | 2:525fb567d140 | 55 | ecran.print(str); |
AxelBoujon | 2:525fb567d140 | 56 | wait(1);*/ |
AxelBoujon | 2:525fb567d140 | 57 | |
AxelBoujon | 2:525fb567d140 | 58 | // PRINT SPECTRUM |
AxelBoujon | 2:525fb567d140 | 59 | for(int j = 0;j < Nb_echantillons/2 ;++j){ |
AxelBoujon | 2:525fb567d140 | 60 | ecran.clear(); |
AxelBoujon | 2:525fb567d140 | 61 | float mod = std::abs(fft_bins[j]); |
AxelBoujon | 2:525fb567d140 | 62 | //float freq = j*sampling_freq/(Nb_echantillons*1000); |
AxelBoujon | 2:525fb567d140 | 63 | /*sprintf(str,"%d.Freq = %.2f kHz", j,freq ); |
AxelBoujon | 2:525fb567d140 | 64 | ecran.locate(0,1); |
AxelBoujon | 2:525fb567d140 | 65 | ecran.print(str); |
AxelBoujon | 2:525fb567d140 | 66 | sprintf(str,"%d.Mag = %.2f", j, mod ); |
AxelBoujon | 2:525fb567d140 | 67 | ecran.locate(0,0); |
AxelBoujon | 2:525fb567d140 | 68 | ecran.print(str);*/ |
AxelBoujon | 2:525fb567d140 | 69 | if( (j>5)and mod >= std::abs(fft_bins[MAX]) ){ |
AxelBoujon | 2:525fb567d140 | 70 | MAX = j; |
AxelBoujon | 2:525fb567d140 | 71 | } |
AxelBoujon | 2:525fb567d140 | 72 | /*else if ( (j>3) and (std::abs(fft_bins[j]) >= std::abs(fft_bins[max2])) and (std::abs(fft_bins[j]) < std::abs(fft_bins[MAX]))){ |
AxelBoujon | 2:525fb567d140 | 73 | max2 = j; |
AxelBoujon | 2:525fb567d140 | 74 | } |
AxelBoujon | 2:525fb567d140 | 75 | wait(1);*/ |
AxelBoujon | 2:525fb567d140 | 76 | } |
AxelBoujon | 2:525fb567d140 | 77 | |
AxelBoujon | 2:525fb567d140 | 78 | val = MAX*sampling_freq/(Nb_echantillons*1000); |
AxelBoujon | 2:525fb567d140 | 79 | float mod = std::abs(fft_bins[MAX]); |
AxelBoujon | 2:525fb567d140 | 80 | /*sprintf(str,"%MAX= %.2f", mod ); |
AxelBoujon | 2:525fb567d140 | 81 | ecran.locate(0,0); |
AxelBoujon | 2:525fb567d140 | 82 | ecran.print(str);*/ |
AxelBoujon | 2:525fb567d140 | 83 | ecran.clear(); |
AxelBoujon | 2:525fb567d140 | 84 | sprintf(str,"max= %.2f kHz", val ); |
AxelBoujon | 2:525fb567d140 | 85 | ecran.locate(0,0); |
AxelBoujon | 2:525fb567d140 | 86 | ecran.print(str); |
AxelBoujon | 2:525fb567d140 | 87 | wait(2); |
AxelBoujon | 2:525fb567d140 | 88 | /*val = max2*sampling_freq/(Nb_echantillons*1000); |
AxelBoujon | 2:525fb567d140 | 89 | sprintf(str,"max 2 = %.2f kHz", val); |
AxelBoujon | 2:525fb567d140 | 90 | ecran.locate(0,1); |
AxelBoujon | 2:525fb567d140 | 91 | ecran.print(str); |
AxelBoujon | 2:525fb567d140 | 92 | wait(2);*/ |
AxelBoujon | 2:525fb567d140 | 93 | samplingBegin(); |
AxelBoujon | 2:525fb567d140 | 94 | } |
SBACCARI | 0:c7f159ed0bc3 | 95 | |
SBACCARI | 0:c7f159ed0bc3 | 96 | int main() { |
SBACCARI | 0:c7f159ed0bc3 | 97 | // CONFIG ECRAN |
SBACCARI | 0:c7f159ed0bc3 | 98 | ecran.setRGB(0, 255, 0); |
SBACCARI | 0:c7f159ed0bc3 | 99 | ecran.clear(); |
SBACCARI | 0:c7f159ed0bc3 | 100 | ecran.locate(0, 1); |
SBACCARI | 0:c7f159ed0bc3 | 101 | samplingBegin(); |
SBACCARI | 0:c7f159ed0bc3 | 102 | // The following loop, will do FFT and display highest detected frequency on the screen every 2s |
AxelBoujon | 2:525fb567d140 | 103 | // Commented sections, are debug mode. If uncommented, it will do FFT, display all the spectrum then restart, it will take about 10s + Nb_echantillons/2 seconds |
SBACCARI | 0:c7f159ed0bc3 | 104 | while(1) { |
SBACCARI | 0:c7f159ed0bc3 | 105 | // DO FFT |
AxelBoujon | 2:525fb567d140 | 106 | if (samplingDone()) FFT(); |
SBACCARI | 0:c7f159ed0bc3 | 107 | /* // DEBUG SCREEN |
SBACCARI | 0:c7f159ed0bc3 | 108 | ecran.clear(); |
SBACCARI | 0:c7f159ed0bc3 | 109 | myled = !myled; |
SBACCARI | 0:c7f159ed0bc3 | 110 | sprintf(str,"Waiting ..."); |
SBACCARI | 0:c7f159ed0bc3 | 111 | ecran.print(str);*/ |
SBACCARI | 0:c7f159ed0bc3 | 112 | } |
SBACCARI | 0:c7f159ed0bc3 | 113 | } |