diff --git a/analyze_fft4096_iqem_F32.h b/analyze_fft4096_iqem_F32.h index 3f7f2f2..b2b35c9 100644 --- a/analyze_fft4096_iqem_F32.h +++ b/analyze_fft4096_iqem_F32.h @@ -1,9 +1,9 @@ /* * analyze_fft4096_iqem_F32.h Assembled by Bob Larkin 18 Feb 2022 * - * External Memory **** BETA TEST VERSION - NOT FULLY TESTED **** <<<<<<<<<< + * External Memory - INO supplied memory arrays. Windows are half width. * - * Note: Teensy 4.x Only, 3.x not supported + * Note: Teensy 4.x ONLY, 3.x not supported * * Does Fast Fourier Transform of a 4096 point complex (I-Q) input. * Output is one of three measures of the power in each of the 4096 @@ -73,7 +73,7 @@ * required if power averaging is used and about 58 kBytes without power averaging. * * In addition, this requires 64 AudioMemory_F32 which work out to about an - * additional 33 kBytesof memory. + * additional 33 kBytes of memory. * * If several FFT sizes are used, one at a time, the memory can be shared. Probably * the simplest way to do this with a Teensy is to set up C-language unions. @@ -96,11 +96,6 @@ * If xAxis=2 f=fs/2 on left edge, f=0 in middle * If xAxis=3 f=fs/2 on right edgr, f=0 in middle * - * If there is 180 degree phase shift to I or Q these all get reversed. - * xAxis=1 is a mathemetically consistent method. It has positive frequencies - * on the right and negative ones on the left. The center is half the sample - * rate, both + and -. Uniormly sampled data lives in this circular world.rate. - * * Timing, maximum microseconds per update() over the 16 updates, * and the average percent processor use for 44.1 kHz sample rate and Nave=1: * T4.0 Windowed, dBFS Out (FFT_DBFS), 710 uSec, Ave 4.64% @@ -119,7 +114,7 @@ * * To use an alternate window function, just fill it into the array, window, above. * It is only half of the window (2048 floats). It looks like a full window - * function with the righ half missing. It should start with small + * function with the right half missing. It should start with small * values on the left (near[0]) and go to 1.0 at the right ([2048]). * * As with all library FFT's this one provides overlapping time series. This @@ -140,7 +135,7 @@ * * 22 Feb 2022 Fixed xAxis error, twice! */ - /* Info + /* Info: * __MK20DX128__ T_LC; __MKL26Z64__ T3.0; __MK20DX256__T3.1 and T3.2 * __MK64FX512__) T3.5; __MK66FX1M0__ T3.6; __IMXRT1062__ T4.0 and T4.1 */ @@ -298,7 +293,7 @@ private: int outputType = FFT_RMS; //Same type as I16 version init int count = 0; int nAverage = 1; - uint8_t xAxis = 0x03; + uint8_t xAxis = 0x03; // See discussion above // The Hann window is a good all-around window // This can be used with zero-bias frequency interpolation.