// TestFFT2048iq.ino for Teensy 4.x // Bob Larkin 9 March 2021 // Generate Sin and Cosine pair and input to IQ FFT. // Serial Print out powers of all 4096 bins in // dB relative to Sine Wave Full Scale // Rev- added i to print; added filters on oscillators. 23 Feb 2022 // Public Domain #include "OpenAudio_ArduinoLibrary.h" #include "AudioStream_F32.h" int jj = 0; // GUItool: begin automatically generated code AudioSynthSineCosine_F32 sine_cos1; //xy=76,532 AudioAnalyzeFFT4096_IQ_F32 FFT4096iq1; //xy=243,532 AudioOutputI2S_F32 audioOutI2S1; //xy=246,591 AudioConnection_F32 patchCord1(sine_cos1, 0, FFT4096iq1, 0); AudioConnection_F32 patchCord2(sine_cos1, 1, FFT4096iq1, 1); // GUItool: end automatically generated code void setup(void) { Serial.begin(9600); delay(1000); // The 4096 complex FFT needs 32 F32 memory for real and 32 for imag. // Set memory to more than 64, depending on other useage. AudioMemory_F32(100); Serial.println("FFT4096IQ Test 2"); sine_cos1.amplitude(1.0f); // Initialize Waveform Generator // Pick T4.x bin center //sine_cos1.frequency(689.0625f); // or pick any old frequency sine_cos1.frequency(1000.0f); // Engage the identical BP Filters on sine/cosine outputs (true). sine_cos1.pureSpectrum(true); // Select the output format FFT_POWER, FFT_RMS or FFT_DBFS FFT4096iq1.setOutputType(FFT_DBFS); // Select the wndow function from these four: //FFT4096iq1.windowFunction(AudioWindowNone); //FFT4096iq1.windowFunction(AudioWindowHanning4096); //FFT4096iq1.windowFunction(AudioWindowKaiser4096, 55.0f); FFT4096iq1.windowFunction(AudioWindowBlackmanHarris4096); // Uncomment to Serial print window function // float* pw = FFT4096iq1.getWindow(); // Print window // for (int i=0; i<4096; i++) Serial.println(pw[i], 7); // x-Axis direction and offset for sine to I and cosine to Q. // If xAxis=0 f=fs/2 in middle, f=0 on right edge // If xAxis=1 f=fs/2 in middle, f=0 on left edge // If xAxis=2 f=fs/2 on left edge, f=0 in middle // If xAxis=3 f=fs/2 on right edge, f=0 in middle // xAxis=3 is mathematically proper -fs/2 start to +fs/2 stop. FFT4096iq1.setXAxis(0X03); FFT4096iq1.setNAverage(5); } void loop(void) { static bool doPrint=true; float *pPwr; // Print output, once if( FFT4096iq1.available() && jj++>2 && doPrint ) { pPwr = FFT4096iq1.getData(); for(int i=0; i<4096; i++) { // Serial.print((int)((float32_t)i * 44100.0/4096.0)); // Print freq Serial.print(i); // FFT Output index (0, 4095) Serial.print(" "); Serial.println(*(pPwr + i), 8 ); } doPrint = false; } if(doPrint) { Serial.print(" Audio MEM Float32 Peak: "); Serial.println(AudioMemoryUsageMax_F32()); } delay(100); }