void do_fft_test()
{
int i, scale;
unsigned diff;
short x[N], fx[N];
printf("Samples: \n");
for (i=0; i<N; i++) {
/*
x[i] = AMPLITUDE*cos(i*FREQUENCY*(2*3.1415926535)/N);
if (i & 0x01)
fx[(N+i)>>1] = x[i];
else
fx[i>>1] = x[i];
*/
#if DEBUG
show_amp(i,x[i], AMPLITUDE);
#endif
}
fix_fftr(fx, log2N, 0);
printf("----------------------------------------------\n");
printf("- Frequencies -\n");
printf("----------------------------------------------\n");
for (i=0; i<N/2; i++) show_amp(i, fx[i], AMPLITUDE);
#if SPECTRUM
for (i=0; i<N/2; i++) show_amp(i, fx[i], AMPLITUDE);
return;
#endif
printf("----------------------------------------------\n");
printf("- Scaled -\n");
printf("----------------------------------------------\n");
scale = fix_fftr(fx, log2N, 1);
//fprintf(stderr, "scale = %d\n", scale);
for (i=0,diff=0; i<N; i++) {
int sample;
if (i & 0x01)
sample = fx[(N+i)>>1] << scale;
else
sample = fx[i>>1] << scale;
#if DEBUG
show_amp(i, sample, AMPLITUDE);
#endif
diff += abs(x[i]-sample);
}
int
main(int argc, char* argv[]) {
volatile int16_t note = -1;
Output_init();
ADC_init(); // Initialize the ADC
Timer2_init(); // Initialize Tim2
while (1) {
if(index == max_index){//we've finished the song... start over!
index = 0;
}
// Check if a data array is ready for FFT processing
if(arrayComplete==1){
arrayComplete = 0; // Reset arrayComplete
// Process the array that completed!
if(array1Complete == 1){
int16_t out = fix_fftr(dataArray1,10,0);
note = getNote(dataArray1);
array1Complete = 0;//mark array as available to re-fill
}
else if(array2Complete == 1) {
int16_t out = fix_fftr(dataArray2,10,0);
note = getNote(dataArray2);
array2Complete = 0;//mark array as available to re-fill
}
int16_t selectedNote = processNote(note);
switch(selectedNote) {
case -2:
// Pause (actually play a frequency so high that no one but dogs can hear it)
TIM2->ARR = 1000000/40000; // Set frequency (40 kHz)
break;
case -1:
// Continue playing the same note
break;
case 0:
// Generate C4 262 Hz
TIM2->ARR = 1000000/262/4; // Set frequency
break;
case 1:
// Generate C#4 277 Hz
TIM2->ARR = 1000000/277/4; // Set frequency
break;
case 2:
// Generate D4 294 Hz
TIM2->ARR = 1000000/294/4; // Set frequency
break;
case 3:
// Generate D#4 311 Hz
TIM2->ARR = 1000000/311/4; // Set frequency
break;
case 4:
// Generate E4 330 Hz
TIM2->ARR = 1000000/330/4; // Set frequency
break;
case 5:
// Generate F4 349 Hz
TIM2->ARR = 1000000/349/4; // Set frequency
break;
case 6:
// Generate F#4 370 Hz
TIM2->ARR = 1000000/370/4; // Set frequency
break;
case 7:
// Generate G4 392 Hz
TIM2->ARR = 1000000/392/4; // Set frequency
break;
case 8:
// Generate G#4 415 Hz
TIM2->ARR = 1000000/415/4; // Set frequency
break;
case 9:
// Generate A4 440 Hz
TIM2->ARR = 1000000/440/4; // Set frequency
break;
case 10:
// Generate A# 466 Hz
TIM2->ARR = 1000000/466/4; // Set frequency
break;
case 11:
// Generate B4 494 Hz
TIM2->ARR = 1000000/494/4; // Set frequency
break;
case 12:
// Generate C5 523 Hz
TIM2->ARR = 1000000/523/4; // Set frequency
break;
case 13:
// Generate C#6 554 Hz
TIM2->ARR = 1000000/554/4; // Set frequency
break;
default:
break;
}
}
}
}
