main.cpp

00001 // Print messages when the AnalogIn is greater than 50%
00002  
00003 #include "mbed.h"
00004 #include "arm_math.h"
00005 #include "arm_const_structs.h"
00006 
00007 
00008 #define led_on  0x00
00009 #define led_off 0x01
00010 
00011 DigitalOut led_r(PTA1);
00012 DigitalOut led_g(PTA2);
00013 DigitalOut led_b(PTD5);
00014 
00015 const int FFT_LEN   = 1024;
00016 const int bins      = 32;
00017 
00018 
00019 const static arm_cfft_instance_f32 *S;
00020 
00021 float samples[FFT_LEN*2];
00022 float magnitudes[FFT_LEN];
00023 float freq_window[bins];
00024 
00025 
00026 int main() 
00027 {   //initialize led to all off
00028     led_r.write(led_off);
00029     led_g.write(led_off);
00030     led_b.write(led_off);  
00031     
00032     
00033     int32_t i = 0;
00034     printf("\r\n\r\nFFT test program!\r\n");
00035     printf("by Curtis Mattull\r\n\r\n\r\n");
00036 
00037 
00038         // Init arm_ccft_32
00039     switch (FFT_LEN)
00040     {
00041     case 16:
00042         S = & arm_cfft_sR_f32_len16;
00043         break;
00044     case 32:
00045         S = & arm_cfft_sR_f32_len32;
00046         break;
00047     case 64:
00048         S = & arm_cfft_sR_f32_len64;
00049         break;
00050     case 128:
00051         S = & arm_cfft_sR_f32_len128;
00052         break;
00053     case 256:
00054         S = & arm_cfft_sR_f32_len256;
00055         break;
00056     case 512:
00057         S = & arm_cfft_sR_f32_len512;
00058         break;
00059     case 1024:
00060         S = & arm_cfft_sR_f32_len1024;
00061         break;
00062     case 2048:
00063         S = & arm_cfft_sR_f32_len2048;
00064         break;
00065     case 4096:
00066         S = & arm_cfft_sR_f32_len4096;
00067         break;
00068     }
00069 
00070     /*populate some dummy sin data*/
00071     for(i = 0; i< FFT_LEN*2; i+=2)
00072     {
00073         //fast math sine table[512+1]
00074         samples[i]      = sinTable_f32[i/4];
00075         samples[i+1]    = 0;
00076     }
00077     
00078     /*multiply the dummy data with more dummy data*/
00079 //    for(i = 0; i< FFT_LEN*2; i+=2)
00080 //    {
00081 //        //fast math sine table[512+1]
00082 //        samples[i]     +=sinTable_f32[i/2] ;
00083 //        samples[i+1]    = 0;
00084 //    }
00085     
00086     // Run FFT on sample data.
00087     arm_cfft_f32(S, samples, 0, 1);
00088     // Calculate magnitude of complex numbers output by the FFT.
00089     arm_cmplx_mag_f32(samples, magnitudes, FFT_LEN);
00090     
00091     printf("\r\nThe first 20 bins:\r\n");
00092     
00093     for(i = 0; i< 20; i++)
00094     {
00095         printf("magnitudes[%i]: %f\r\n",i,magnitudes[i]);
00096     }
00097     
00098     led_g.write(led_on);
00099 
00100     printf("test complete\r\n");
00101     wait(1);
00102     while(1) 
00103     {
00104         
00105     }
00106 }