Revision 2:525fb567d140, committed 2019-05-31

Comitter:

AxelBoujon

Date:

Fri May 31 11:30:06 2019 +0000

Parent:

1:a806f3aacf1f

Commit message:

Projet de FFT

Changed in this revision

diff -r a806f3aacf1f -r 525fb567d140 main.cpp
--- a/main.cpp	Mon Apr 15 10:08:19 2019 +0000
+++ b/main.cpp	Fri May 31 11:30:06 2019 +0000
@@ -2,22 +2,26 @@
 #include "Grove_LCD_RGB_Backlight.h"
 #include "fftReal.hpp"
 
+#define Nb_echantillons 256
+
+//Elements
 Grove_LCD_RGB_Backlight ecran(P0_27, P0_28);
 AnalogIn micro(A1);
-DigitalOut myled(LED1);
 
-Ticker sampler;
-const int FFT_len = 256;
+//Variables
+Ticker echantillonage;
 int sampling_freq = 44000;
-float samples[FFT_len*2];
+float echantillons[Nb_echantillons*2];
 int i = 0;
+Mikami::Complex fft_bins[Nb_echantillons];
+Mikami::FftReal fft((int16_t)Nb_echantillons);
 
 void sampling_interrup()
 {
-    samples[i] = 1024*micro.read(); // 1024 : ADC of the sound sensor
+    echantillons[i] = 1024*micro.read(); // 1024 : ADC of the sound sensor
     i++;
-    if (i >= FFT_len*2) {
-        sampler.detach();
+    if (i >= Nb_echantillons*2) {
+        echantillonage.detach();
     }
 }
 
@@ -25,109 +29,81 @@
 {
     // Reset sample buffer position and start callback at the sampling frequency
     i = 0;
-    sampler.attach_us(&sampling_interrup, 1000000/sampling_freq);
+    echantillonage.attach_us(&sampling_interrup, 1000000/sampling_freq);
 }
 
 bool samplingDone()
 {
-    return i >= FFT_len*2;
+    return i >= Nb_echantillons*2;
 }
 
+void FFT(){
+    char str[20];
+    // max 1 is set to the second FFT bin, because the first bin has the DC componenet of the signal.
+    int MAX = 2; 
+    //int max2 = 3;
+    float val = 0;
+    /*ecran.locate(0, 0);
+    sprintf(str,"Sampling done");
+    ecran.print(str);
+    wait(1);*/
+    fft.Execute(echantillons,fft_bins);
+    wait(0.5);
+    
+    /*ecran.clear();
+    sprintf(str,"FFT Done");
+    ecran.print(str);
+    wait(1);*/
+    
+    // PRINT SPECTRUM
+    for(int j = 0;j < Nb_echantillons/2 ;++j){
+        ecran.clear();
+        float mod = std::abs(fft_bins[j]);
+        //float freq = j*sampling_freq/(Nb_echantillons*1000);
+        /*sprintf(str,"%d.Freq = %.2f kHz", j,freq );
+        ecran.locate(0,1);
+        ecran.print(str);
+        sprintf(str,"%d.Mag = %.2f", j, mod );
+        ecran.locate(0,0);
+        ecran.print(str);*/
+        if( (j>5)and mod >= std::abs(fft_bins[MAX]) ){
+            MAX = j;
+        }
+        /*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]))){
+            max2 = j;
+        }
+        wait(1);*/
+    }
+    
+    val = MAX*sampling_freq/(Nb_echantillons*1000);
+    float mod = std::abs(fft_bins[MAX]);
+    /*sprintf(str,"%MAX= %.2f", mod );
+    ecran.locate(0,0);
+    ecran.print(str);*/
+    ecran.clear();
+    sprintf(str,"max= %.2f kHz", val );
+    ecran.locate(0,0);
+    ecran.print(str);
+    wait(2);
+    /*val =  max2*sampling_freq/(Nb_echantillons*1000);
+    sprintf(str,"max 2 = %.2f kHz", val);
+    ecran.locate(0,1);
+    ecran.print(str);
+    wait(2);*/
+    samplingBegin();
+}
 
 int main() {
-    char str[20];
-    
-    // max 1 is set to the second FFT bin, because the first bin has the DC componenet of the signal.
-    int max1 = 2; 
-    int max2 = 3;
-    float val = 0;
-    
-    // CONFIG FFT
-    Mikami::Complex fft_bins[FFT_len];
-    Mikami::FftReal fft((int16_t)FFT_len);
-
     // CONFIG ECRAN
     ecran.setRGB(0, 255, 0);
     ecran.clear();
     ecran.locate(0, 1);
-    
     samplingBegin();
-    
     // The following loop, will do FFT and display highest detected frequency on the screen every 2s
-    // Commented sections, are debug mode. If uncommented, it will do FFT, display all the  spectrum then restart, it will take about 10s + FFT_len/2 seconds
-    
+    // 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
     while(1) {
-        /*ecran.clear();
-        sprintf(str,"Sampling ...");
-        ecran.print(str);
-        ecran.setRGB(255, 0, 0);
-        wait(0.6);
-        ecran.setRGB(0, 0, 255);
-        wait(0.6);
-        ecran.setRGB(0, 255, 0);*/
-        
         // DO FFT
-        if (samplingDone())
-        {
-            /*ecran.locate(0, 0);
-            sprintf(str,"Sampling done");
-            ecran.print(str);
-            wait(1);*/
-                
-            fft.Execute(samples,fft_bins);
-            wait(0.5);
-            
-            /*ecran.clear();
-            sprintf(str,"FFT Done");
-            ecran.print(str);
-            wait(1);*/
-            
-            // PRINT SPECTRUM
-            for(int j = 0;j < FFT_len/2 ;++j){
-                ecran.clear();
-                float mod = std::abs(fft_bins[j]);
-                float freq = j*sampling_freq/(FFT_len*1000);
-                
-                /*sprintf(str,"%d.Freq = %.2f kHz", j,freq );
-                ecran.locate(0,1);
-                ecran.print(str);
-                
-                sprintf(str,"%d.Mag = %.2f", j, mod );
-                ecran.locate(0,0);
-                ecran.print(str);*/
-                
-                if( (j>5)and mod >= std::abs(fft_bins[max1]) ){
-                    max1 = j;
-                }
-                /*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[max1]))){
-                    max2 = j;
-                }
-                wait(1);*/
-            }
-            
-            val = max1*sampling_freq/(FFT_len*1000);
-            float mod = std::abs(fft_bins[max1]);
-            
-            /*sprintf(str,"%max1= %.2f", mod );
-            ecran.locate(0,0);
-            ecran.print(str);*/
-            
-            ecran.clear();
-            sprintf(str,"max= %.2f kHz", val );
-            ecran.locate(0,0);
-            ecran.print(str);
-            wait(2);
-
-            /*val =  max2*sampling_freq/(FFT_len*1000);
-            sprintf(str,"max 2 = %.2f kHz", val);
-            ecran.locate(0,1);
-            ecran.print(str);
-            wait(2);*/
-                
-            samplingBegin();
-                
-        }
-        
+        if (samplingDone()) FFT();
         /* // DEBUG SCREEN
         ecran.clear();
         myled = !myled;