Diff: main.cpp

Revision:

0:dc6175686e56

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Jul 28 13:48:16 2014 +0000
@@ -0,0 +1,197 @@
+#define SAMPLE_RATE   48000
+
+
+#include "mbed.h"
+#include "adc.h"
+#include "PololuLedStrip.h"
+
+PololuLedStrip ledStrip(p8);
+
+#define LED_COUNT 60
+rgb_color colors[LED_COUNT];
+
+Serial pc(USBTX,USBRX);
+
+//extern "C" void cr4_fft_256_stm32(void *pssOUT, void *pssIN, uint16_t Nbin);
+extern "C" void fftR4(short *y, short *x, int N);
+
+//use the LED as a bargraph
+DigitalOut l1(LED1);
+DigitalOut l2(LED2);
+DigitalOut l3(LED3);
+DigitalOut l4(LED4);
+
+//set up a timer for timing FFT's
+Timer timer;
+
+//Used to change colour of LED strips
+//int testX = 0;
+
+//Set up filesystem so we can write some useful files
+
+LocalFileSystem local("local");              
+FILE *fp;
+
+//Set up a global buffer for audio data so interrupt can access it
+int Counter = 0;
+int16_t Buffer[5000];
+int16_t VoltageBuffer[5000];
+
+//Initialise ADC to maximum SAMPLE_RATE and cclk divide set to 1
+ADC adc(SAMPLE_RATE, 1);
+
+int colourVoltage=0;
+
+
+
+//Our interrupt handler for audio sampling
+void sample_ADC(int chan, uint32_t value) {
+    
+   float s;
+   s = adc.read(p20); 
+   int16_t b = (s -2048)*16;
+   Buffer[Counter] = b;
+   
+   Counter += 1;
+    /* bar graph */
+     
+    int g = abs(s-2048);
+    l1 = g > 0.1f*2048;
+    l2 = g > 0.3f*2048;
+    l3 = g > 0.6f*2048;
+    l4 = g > 0.8f*2048;
+}
+
+
+    
+    
+    
+    
+int main() {
+    
+while (1){
+    
+    //Prepare for burst mode on all ADC pins and set up interrupt handler (using ADC library from Simon Blandford
+    adc.append(sample_ADC);
+    adc.startmode(0,0);
+    adc.burst(1);
+    adc.setup(p20,1);
+    //introduce a delay as initial waveform has bias whilst decoupling cap charges
+    wait(0.05);
+    //start the interrupt and wait for about 4096 samples
+    adc.interrupt_state(p20,1);
+    wait(0.05);
+    
+        //Finsh up - Unset pin 20
+        adc.interrupt_state(p20,0);
+        adc.setup(p20,0);
+        int actual_rate = adc.actual_sample_rate();
+//now lets try mellen fft-------------------------
+        timer.reset();
+        timer.start();
+        #define MN 1024 /*Number of points*/
+        short mx[MN*2]; // input data 16 bit, 4 byte aligned  x0r,x0i,x1r,x1i,....
+        short my[MN*2]; // output data 16 bit,4 byte aligned  y0r,y0i,y1r,y1i,....
+        float mz[MN*2]; // to store the final result
+        for (int i=0;i<MN*2;i++) mx[i]=0;
+        for (int i=0;i<MN*2;i++) mz[i]=0;
+        for (int i=0;i<MN;i=i+1)
+            { mx[i*2]=Buffer[i];}
+        //printf("Mellen set up took %i\n",timer.read_us());
+        //call functions
+        timer.reset();
+        timer.start();
+        fftR4(my, mx, MN);
+        //printf("Mellen fft took %i\n",timer.read_us());
+//FILE* mlog = fopen("/local/mellen.csv","w");
+        
+        //now write a CSV file to filesytem of frequency vs amplitude
+        for (int i=0; i<MN; i=i+2)
+        {
+          //  fprintf(mlog, "%d: %d -> %d\n", i, mx[i], my[i]);
+            //fprintf(mlog, "%d,%f\n", int(actual_rate/MN/2*i),sqrt(float(   (my[i]*my[i])  +(my[i+1]*my[i+1])     ) )   );          
+        
+        mz[i]=sqrt(float(   (my[i]*my[i])  +(my[i+1]*my[i+1])     ) ) ;
+         //fprintf(mlog, "%f\n", mz[i]  );
+        }
+       
+        
+        // detect the change of input frequency ******************************
+    float maxFreq=0;
+    float max=0;
+    for (int i=2;i<512;i=i+1){
+           
+        if(mz[i]>max){
+            max = mz[i];
+            maxFreq=i;
+            }//end if
+        
+        }//end for
+    //fprintf(mlog, "%d\n",maxFreq  );
+    
+    int maxVoltage=0;
+    for (int i=0;i<512;i=i+1){
+           
+        if(mx[i]>maxVoltage){
+            maxVoltage = mx[i];
+           
+            }//end if
+        }//end for
+    
+pc.printf(" the max = %f\n",max );
+pc.printf(" the maxFreq = %f\n",maxFreq );
+pc.printf(" the colourValtage = %d\n", maxVoltage );
+
+
+        /*for (int i = 0; i < LED_COUNT; i++){
+        colors[i] = (rgb_color){ 0, 0, 0 };  
+        } 
+        
+        if (maxFreq>60) maxFreq=60; // Limiting Length
+        
+         for (int i = 0; i < maxFreq; i++){
+            colors[i] = (rgb_color){ abs(maxVoltage/11),abs(255-(maxVoltage/11)) ,abs(255-(maxVoltage/11)+50)  };
+            }   
+             ledStrip.write(colors, LED_COUNT);*/
+            int actualFreq= (actual_rate/MN/2*maxFreq);
+            pc.printf(" actualFreq = %d\n", actualFreq );
+            
+            
+            //wait_ms(10);
+            
+            /*if (maxFreq>30){
+            //testX=200;
+            for (int i = 0; i < LED_COUNT; i++){
+            colors[i] = (rgb_color){ 0, 20, 200 };
+            }
+            }
+
+        if ((maxFreq>22)&&(maxFreq<30)){// if frequency bigger than 966Hz
+            //testX= 10;
+            for (int i = 0; i < LED_COUNT; i++){
+            colors[i] = (rgb_color){ 250, 0, 0 };
+            
+            }
+            }
+        if (maxFreq<22){
+            //testX=200;
+            for (int i = 0; i < LED_COUNT; i++){
+            colors[i] = (rgb_color){ 0, 250, 0 };
+            }
+            }*/
+
+    
+     
+       
+        
+            
+            
+            //-----------
+        
+        
+        //fclose(mlog);    
+  Counter = 0;
+        }// end while (1)
+        
+    
+}
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