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/*
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* analyze_fft4096_iq_F32.cpp Assembled by Bob Larkin 9 Mar 2021 |
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* |
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* External Memory **** BETA TEST VERSION - NOT FULLY TESTED **** <<<<<<<<<< |
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* |
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* This class is Teensy 4.x ONLY. |
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* F32 Bolocks are always 128 floats, and any data rate is OK. |
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* |
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* Converted to F32 floating point input and also extended |
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* for complex I and Q inputs |
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* * Adapted all I/O to be F32 floating point for OpenAudio_ArduinoLibrary |
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* * Future: Add outputs for I & Q FFT x2 for overlapped FFT |
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* * Windowing None, Hann, Kaiser and Blackman-Harris. |
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* |
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* Conversion Copyright (c) 2021 Bob Larkin |
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* Same MIT license as PJRC: |
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* |
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* Audio Library for Teensy 3.X |
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* Copyright (c) 2014, Paul Stoffregen, paul@pjrc.com |
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* |
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* Development of this audio library was funded by PJRC.COM, LLC by sales of |
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* Teensy and Audio Adaptor boards. Please support PJRC's efforts to develop |
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* open source software by purchasing Teensy or other PJRC products. |
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* |
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* Permission is hereby granted, free of charge, to any person obtaining a copy |
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* of this software and associated documentation files (the "Software"), to deal |
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* in the Software without restriction, including without limitation the rights |
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
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* copies of the Software, and to permit persons to whom the Software is |
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* furnished to do so, subject to the following conditions: |
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* |
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* The above copyright notice, development funding notice, and this permission |
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* notice shall be included in all copies or substantial portions of the Software. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
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* THE SOFTWARE. |
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*/ |
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// *************** TEENSY 4.X ONLY ****************
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#if defined(__IMXRT1062__) |
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#include <Arduino.h> |
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#include "analyze_fft4096_iqem_F32.h" |
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// Note: Suppports block size of 128 only. Very "built in."
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// Move audio data from audio_block_f32_t to the interleaved FFT instance buffer.
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static void copy_to_fft_buffer1(void *destination, const void *sourceI, const void *sourceQ) { |
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const float *srcI = (const float *)sourceI; |
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const float *srcQ = (const float *)sourceQ; |
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float *dst = (float *)destination; // part of fft_buffer array. 256 floats per call
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for (int i=0; i < 128; i++) { |
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*dst++ = *srcI++; // real sample, interleave
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*dst++ = *srcQ++; // imag
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} |
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} |
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void AudioAnalyzeFFT4096_IQEM_F32::update(void) { |
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audio_block_f32_t *block_i,*block_q; |
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int i, ii; |
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block_i = receiveReadOnly_f32(0); |
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if (!block_i) return; |
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block_q = receiveReadOnly_f32(1); |
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if (!block_q) { |
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release(block_i); |
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return; |
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} |
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// Here with two new blocks of data. These are retained until the FFT
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// but with new pointers, blocklist_i[] and blocklist_q[].
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switch (state) { |
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case 0: |
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blocklist_i[0] = block_i; blocklist_q[0] = block_q; // Copy 2 ptrs
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state = 1; |
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break; |
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case 1: |
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blocklist_i[1] = block_i; blocklist_q[1] = block_q; |
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state = 2; |
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break; |
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case 2: |
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blocklist_i[2] = block_i; blocklist_q[2] = block_q; |
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state = 3; |
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break; |
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case 3: |
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blocklist_i[3] = block_i; blocklist_q[3] = block_q; |
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state = 4; |
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break; |
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case 4: |
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blocklist_i[4] = block_i; blocklist_q[4] = block_q; |
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state = 5; |
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break; |
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case 5: |
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blocklist_i[5] = block_i; blocklist_q[5] = block_q; |
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state = 6; |
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break; |
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case 6: |
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blocklist_i[6] = block_i; blocklist_q[6] = block_q; |
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state = 7; |
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break; |
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case 7: |
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blocklist_i[7] = block_i; blocklist_q[7] = block_q; |
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state = 8; |
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break; |
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case 8: |
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blocklist_i[8] = block_i; blocklist_q[8] = block_q; |
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state = 9; |
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break; |
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case 9: |
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blocklist_i[9] = block_i; blocklist_q[9] = block_q; |
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state = 10; |
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break; |
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case 10: |
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blocklist_i[10] = block_i; blocklist_q[10] = block_q; |
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state = 11; |
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break; |
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case 11: |
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blocklist_i[11] = block_i; blocklist_q[11] = block_q; |
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state = 12; |
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break; |
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case 12: |
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blocklist_i[12] = block_i; blocklist_q[12] = block_q; |
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state = 13; |
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break; |
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case 13: |
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blocklist_i[13] = block_i; blocklist_q[13] = block_q; |
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state = 14; |
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break; |
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case 14: |
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blocklist_i[14] = block_i; blocklist_q[14] = block_q; |
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state = 15; |
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break; |
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case 15: |
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blocklist_i[15] = block_i; blocklist_q[15] = block_q; |
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state = 16; |
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break; |
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// ********************************************************
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// Once things are running, the loop comes back to this point
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case 16: |
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blocklist_i[16] = block_i; blocklist_q[16] = block_q; |
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// Now work on the FFT output data. This was created in case 31.
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// This next forming of the sumsq[] takes 48 uSec
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count++; |
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for (int i = 0; i < 2048; i++) { |
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// Re-arranging the coefficients. These are bin powers (not Volts)
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// See DD4WH SDR
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float ss0 = *(pFFT_buffer + 2*i) * *(pFFT_buffer + 2*i) + |
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*(pFFT_buffer + 2*i+1) * *(pFFT_buffer + 2*i+1); |
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float ss1 = *(pFFT_buffer + 2*(i+2048)) * *(pFFT_buffer + 2*(i+2048)) + |
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*(pFFT_buffer + 2*(i+2048)+1) * *(pFFT_buffer + 2*(i+2048)+1); |
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if(!(pSumsq==NULL)) { // We have memory to do averages
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if(count==1) { // Starting new average
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*(pSumsq+i+2048) = ss0; |
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*(pSumsq+i) = ss1; |
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} |
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else if (count <= nAverage) { // Adding on to average
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*(pSumsq+i+2048) += ss0; |
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*(pSumsq+i) += ss1; |
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} |
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} |
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else // No averaging is used
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{ |
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// Parts of pFFT_buffer are becoming available for
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// temporary storage, but not all:
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*(pFFT_buffer+i) = ss0; |
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*(pFFT_buffer+4096+i) = ss1; |
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// Now in pFFT_buffer 0,2047 and 4096,6143
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} |
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} |
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// sumsq[] is filled. Wait to state==17 to convert to dBFS, etc
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state = 17; |
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break; |
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case 17: |
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blocklist_i[17] = block_i; blocklist_q[17] = block_q; |
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// This state==17 block takes 710 uSec for DBFS, but
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// only 65 for POWER. DB conversions do not need to be under
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// this interrupt and POWER output should be used if time is short.
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if (pSumsq==NULL || count>=nAverage) { // Average is not being done or is finished
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outputflag = false; // Avoid starting read() during block 17 to 18
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float inAf = 1.0f/(float)nAverage; |
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for (ii=0; ii < 2048; ii++) { |
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// xAxis, bit 0 left/right; bit 1 low to high
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if(xAxis & 0X02) |
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i = ii; |
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else |
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i = ii^2048; |
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if(xAxis & 0X01) |
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i = (4095 - i); |
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if(!(pSumsq==NULL)) { // We have memory to do averages
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if(outputType==FFT_RMS) |
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*(pOutput+i) = sqrtf(inAf* *(pSumsq+ii)); |
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else if(outputType==FFT_POWER) |
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*(pOutput+i) = inAf* *(pSumsq+ii); |
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else if(outputType==FFT_DBFS) |
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*(pOutput+i) = 10.0f*log10f(inAf* *(pSumsq+ii))-66.23f; // Scaled to FS sine wave
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else |
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*(pOutput+i) = 0.0f; |
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} |
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else { // No averaging
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if(outputType==FFT_RMS) |
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*(pOutput+i) = sqrtf(*(pFFT_buffer+ii)); |
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else if(outputType==FFT_POWER) |
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*(pOutput+i) = *(pFFT_buffer+ii); |
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else if(outputType==FFT_DBFS) |
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*(pOutput+i) = 10.0f*log10f(*(pFFT_buffer+ii))-66.23f; |
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} // End, no averaging
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} // End of "over all i"
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} // end of Average is Finished
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state = 18; |
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break; |
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case 18: |
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blocklist_i[18] = block_i; blocklist_q[18] = block_q; |
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// Second half of post-FFT processing. dBFS (log10f) is the big user of time.
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if (pSumsq==NULL || count>=nAverage) { // Average is finished
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Serial.println(count); |
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count = 0; // CHECK WHERE IS count++ ??? <<<<<<<<<<<<<<
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float inAf = 1.0f/(float)nAverage; |
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// ii is the index to data source, i is for data output
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for (int ii=2048; ii < 4096; ii++) { |
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// xAxis, bit 0 left/right; bit 1 low to high
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if(xAxis & 0X02) |
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i = ii; |
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else |
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i = ii^2048; |
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if(xAxis & 0X01) |
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i = (4095 - i); |
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if(!(pSumsq==NULL)) { // We have memory to do averages
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if(outputType==FFT_RMS) |
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*(pOutput+i) = sqrtf(inAf* *(pSumsq+ii)); |
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else if(outputType==FFT_POWER) |
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*(pOutput+i) = inAf* *(pSumsq+ii); |
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else if(outputType==FFT_DBFS) |
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*(pOutput+i) = 10.0f*log10f(inAf* *(pSumsq+ii))-66.23f; // Scaled to FS sine wave
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else |
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*(pOutput+i) = 0.0f; |
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} |
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else { // No averaging being done
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if(outputType==FFT_RMS) |
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*(pOutput+i) = sqrtf(*(pFFT_buffer+ii+2048)); |
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else if(outputType==FFT_POWER) |
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*(pOutput+i) = *(pFFT_buffer+ii+2048); |
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else if(outputType==FFT_DBFS) |
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*(pOutput+i) = 10.0f*log10f(*(pFFT_buffer+ii+2048))-66.23f; |
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else |
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*(pOutput+i) = 0.0f; |
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} |
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} |
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outputflag = true; |
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} // end of Average is Finished
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state = 19; |
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break; |
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case 19: |
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blocklist_i[19] = block_i; blocklist_q[19] = block_q; |
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state = 20; |
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break; |
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case 20: |
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blocklist_i[20] = block_i; blocklist_q[20] = block_q; |
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state = 21; |
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break; |
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case 21: |
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blocklist_i[21] = block_i; blocklist_q[21] = block_q; |
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state = 22; |
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break; |
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case 22: |
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blocklist_i[22] = block_i; blocklist_q[22] = block_q; |
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state = 23; |
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break; |
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case 23: |
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blocklist_i[23] = block_i; blocklist_q[23] = block_q; |
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state = 24; |
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break; |
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case 24: |
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blocklist_i[24] = block_i; blocklist_q[24] = block_q; |
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state = 25; |
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break; |
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case 25: |
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blocklist_i[25] = block_i; blocklist_q[25] = block_q; |
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state = 26; |
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break; |
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case 26: |
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blocklist_i[26] = block_i; blocklist_q[26] = block_q; |
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state = 27; |
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break; |
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case 27: |
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blocklist_i[27] = block_i; blocklist_q[27] = block_q; |
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state = 28; |
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break; |
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case 28: |
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blocklist_i[28] = block_i; blocklist_q[28] = block_q; |
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state = 29; |
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break; |
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case 29: |
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blocklist_i[29] = block_i; blocklist_q[29] = block_q; |
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state = 30; |
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break; |
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case 30: |
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blocklist_i[30] = block_i; blocklist_q[30] = block_q; |
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state = 31; |
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break; |
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case 31: |
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blocklist_i[31] = block_i; blocklist_q[31] = block_q; |
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// Copy 8192 data to fft_buffer This state==31 takes about 500 uSec, including the FFT.
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// i & q interleaved data.
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copy_to_fft_buffer1(pFFT_buffer+0x000, blocklist_i[0]->data, blocklist_q[0]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x100, blocklist_i[1]->data, blocklist_q[1]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x200, blocklist_i[2]->data, blocklist_q[2]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x300, blocklist_i[3]->data, blocklist_q[3]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x400, blocklist_i[4]->data, blocklist_q[4]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x500, blocklist_i[5]->data, blocklist_q[5]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x600, blocklist_i[6]->data, blocklist_q[6]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x700, blocklist_i[7]->data, blocklist_q[7]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x800, blocklist_i[8]->data, blocklist_q[8]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x900, blocklist_i[9]->data, blocklist_q[9]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0xA00, blocklist_i[10]->data, blocklist_q[10]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0xB00, blocklist_i[11]->data, blocklist_q[11]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0xC00, blocklist_i[12]->data, blocklist_q[12]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0xD00, blocklist_i[13]->data, blocklist_q[13]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0xE00, blocklist_i[14]->data, blocklist_q[14]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0xF00, blocklist_i[15]->data, blocklist_q[15]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x1000, blocklist_i[16]->data, blocklist_q[16]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x1100, blocklist_i[17]->data, blocklist_q[17]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x1200, blocklist_i[18]->data, blocklist_q[18]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x1300, blocklist_i[19]->data, blocklist_q[19]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x1400, blocklist_i[20]->data, blocklist_q[20]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x1500, blocklist_i[21]->data, blocklist_q[21]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x1600, blocklist_i[22]->data, blocklist_q[22]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x1700, blocklist_i[23]->data, blocklist_q[23]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x1800, blocklist_i[24]->data, blocklist_q[24]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x1900, blocklist_i[25]->data, blocklist_q[25]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x1A00, blocklist_i[26]->data, blocklist_q[26]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x1B00, blocklist_i[27]->data, blocklist_q[27]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x1C00, blocklist_i[28]->data, blocklist_q[28]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x1D00, blocklist_i[29]->data, blocklist_q[29]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x1E00, blocklist_i[30]->data, blocklist_q[30]->data); |
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copy_to_fft_buffer1(pFFT_buffer+0x1F00, blocklist_i[31]->data, blocklist_q[31]->data); |
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// Apply the window function, if any, to the time series. Half size window buffer.
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if(wNum!=NULL && pWindow) |
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{ |
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for (int i=0; i < 2048; i++) { |
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*(pFFT_buffer + 2*i) *= *(pWindow + i); // real
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*(pFFT_buffer + 2*i+1) *= *(pWindow + i); // imag
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} |
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for (int i=0; i < 2048; i++) { // Second half
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*(pFFT_buffer + 8191 - 2*i) *= *(pWindow + i); |
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*(pFFT_buffer + 8190 - 2*i) *= *(pWindow + i); |
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} |
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} |
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// Teensyduino core for T4.x supports arm_cfft_f32
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// arm_cfft_f32 (const arm_cfft_instance_f32 *S, float32_t *p1,
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// uint8_t ifftFlag, uint8_t bitReverseFlag)
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// I & O are real/imag interleaved in 8192-float point array p1.
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arm_cfft_f32(&Sfft, pFFT_buffer, 0, 1); |
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release(blocklist_i[0]); release(blocklist_q[0]); |
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release(blocklist_i[1]); release(blocklist_q[1]); |
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release(blocklist_i[2]); release(blocklist_q[2]); |
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release(blocklist_i[3]); release(blocklist_q[3]); |
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release(blocklist_i[4]); release(blocklist_q[4]); |
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release(blocklist_i[5]); release(blocklist_q[5]); |
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release(blocklist_i[6]); release(blocklist_q[6]); |
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release(blocklist_i[7]); release(blocklist_q[7]); |
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release(blocklist_i[8]); release(blocklist_q[8]); |
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release(blocklist_i[9]); release(blocklist_q[9]); |
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release(blocklist_i[10]); release(blocklist_q[10]); |
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release(blocklist_i[11]); release(blocklist_q[11]); |
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release(blocklist_i[12]); release(blocklist_q[12]); |
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release(blocklist_i[13]); release(blocklist_q[13]); |
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release(blocklist_i[14]); release(blocklist_q[14]); |
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release(blocklist_i[15]); release(blocklist_q[15]); |
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blocklist_i[0] = blocklist_i[16]; |
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blocklist_i[1] = blocklist_i[17]; |
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blocklist_i[2] = blocklist_i[18]; |
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blocklist_i[3] = blocklist_i[19]; |
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blocklist_i[4] = blocklist_i[20]; |
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blocklist_i[5] = blocklist_i[21]; |
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blocklist_i[6] = blocklist_i[22]; |
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blocklist_i[7] = blocklist_i[23]; |
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blocklist_i[8] = blocklist_i[24]; |
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blocklist_i[9] = blocklist_i[25]; |
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blocklist_i[10] = blocklist_i[26]; |
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blocklist_i[11] = blocklist_i[27]; |
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blocklist_i[12] = blocklist_i[28]; |
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blocklist_i[13] = blocklist_i[29]; |
||||
blocklist_i[14] = blocklist_i[30]; |
||||
blocklist_i[15] = blocklist_i[31]; |
||||
|
||||
blocklist_q[0] = blocklist_q[16]; |
||||
blocklist_q[1] = blocklist_q[17]; |
||||
blocklist_q[2] = blocklist_q[18]; |
||||
blocklist_q[3] = blocklist_q[19]; |
||||
blocklist_q[4] = blocklist_q[20]; |
||||
blocklist_q[5] = blocklist_q[21]; |
||||
blocklist_q[6] = blocklist_q[22]; |
||||
blocklist_q[7] = blocklist_q[23]; |
||||
blocklist_q[8] = blocklist_q[24]; |
||||
blocklist_q[9] = blocklist_q[25]; |
||||
blocklist_q[10] = blocklist_q[26]; |
||||
blocklist_q[11] = blocklist_q[27]; |
||||
blocklist_q[12] = blocklist_q[28]; |
||||
blocklist_q[13] = blocklist_q[29]; |
||||
blocklist_q[14] = blocklist_q[30]; |
||||
blocklist_q[15] = blocklist_q[31]; |
||||
|
||||
state = 16; |
||||
break; // From case 31
|
||||
} // End of switch & case 31
|
||||
} // End update()
|
||||
// End, if Teensy 4.x
|
||||
#endif |
@ -0,0 +1,348 @@ |
||||
/*
|
||||
* analyze_fft4096_iqem_F32.h Assembled by Bob Larkin 9 Mar 2021 |
||||
* |
||||
* External Memory **** BETA TEST VERSION - NOT FULLY TESTED **** <<<<<<<<<< |
||||
* |
||||
* 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 |
||||
* output bins, Power, RMS level or dB relative to a full scale |
||||
* sine wave. Windowing of the input data is provided for to reduce |
||||
* spreading of the power in the output bins. All inputs are Teensy |
||||
* floating point extension (_F32) and all outputs are floating point. |
||||
* |
||||
* Features include: |
||||
* * I and Q inputs are OpenAudio_Arduino Library F32 compatible. |
||||
* * FFT output for every 2048 inputs to overlapped FFTs to |
||||
* compensate for windowing. |
||||
* * Windowing None, Hann, Kaiser and Blackman-Harris. |
||||
* * Multiple bin-sum output to simulate wider bins. |
||||
* * Power averaging of multiple FFT |
||||
* |
||||
* Conversion Copyright (c) 2021 Bob Larkin |
||||
* Same MIT license as PJRC: |
||||
* |
||||
* From original real FFT: |
||||
* Audio Library for Teensy 3.X |
||||
* Copyright (c) 2014, Paul Stoffregen, paul@pjrc.com |
||||
* |
||||
* Development of this audio library was funded by PJRC.COM, LLC by sales of |
||||
* Teensy and Audio Adaptor boards. Please support PJRC's efforts to develop |
||||
* open source software by purchasing Teensy or other PJRC products. |
||||
* |
||||
* Permission is hereby granted, free of charge, to any person obtaining a copy |
||||
* of this software and associated documentation files (the "Software"), to deal |
||||
* in the Software without restriction, including without limitation the rights |
||||
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
||||
* copies of the Software, and to permit persons to whom the Software is |
||||
* furnished to do so, subject to the following conditions: |
||||
* |
||||
* The above copyright notice, development funding notice, and this permission |
||||
* notice shall be included in all copies or substantial portions of the Software. |
||||
* |
||||
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
||||
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
||||
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
||||
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
||||
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
||||
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
||||
* THE SOFTWARE. |
||||
*/ |
||||
|
||||
/* Does complex input FFT of 4096 points. Multiple non-audio (via functions)
|
||||
* output formats of RMS (same as I16 version, and default), |
||||
* Power or dBFS (full scale). Output can be bin by bin or a pointer to |
||||
* the output array is available. Several window functions are provided by |
||||
* in-class design, or a custom window can be provided from the INO. |
||||
* |
||||
* Memory for IQem FFT. The large blocks of memory must be declared in the INO. |
||||
* This typically looks like: |
||||
* float32_t fftOutput[4096]; // Array used for FFT Output to the INO program
|
||||
* float32_t window[2048]; // Windows reduce sidelobes with FFT's *Half Size*
|
||||
* float32_t fftBuffer[8192]; // Used by FFT, 4096 real, 4096 imag, interleaved
|
||||
* float32_t sumsq[4096]; // Required ONLY if power averaging is being done
|
||||
* |
||||
* These blocks of memory are communicated to the FFT in the object creation, that |
||||
* might look like: |
||||
* AudioAnalyzeFFT4096_IQEM_F32 myFFT(fftOutput, window, fftBuffer); |
||||
* or, if power averaging is used, the extra parameter is needed as: |
||||
* AudioAnalyzeFFT4096_IQEM_F32 myFFT(fftOutput, window, fftBuffer, sumsq); |
||||
* |
||||
* The memory arrays must be declared before the FFT object. About 74 kBytes are |
||||
* 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. |
||||
* |
||||
* 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. |
||||
* |
||||
* Functions (See comments below and #defines above: |
||||
* bool available() |
||||
* float read(unsigned int binNumber) |
||||
* float read(unsigned int binFirst, unsigned int binLast) |
||||
* int windowFunction(int wNum) |
||||
* int windowFunction(int wNum, float _kdb) // Kaiser only
|
||||
* void setNAverage(int NAve) // >=1
|
||||
* void setOutputType(int _type) |
||||
* void setXAxis(uint8_t _xAxis) // 0, 1, 2, 3
|
||||
* |
||||
* x-Axis direction and offset per setXAxis(xAxis) for sine to I |
||||
* and cosine to Q: |
||||
* If xAxis=0 f=0 in middle, f=fs/2 on left edge |
||||
* If xAxis=1 f=0 in middle, f=fs/2 on right edge |
||||
* If xAxis=2 f=0 on right edge, f=fs/2 in middle |
||||
* If xAxis=3 f=0 on left edge, f=fs/2 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, max is longest update() time: |
||||
* T4.0 Windowed, dBFS Out, 987 uSec <<<<<<CHECK |
||||
* |
||||
* Windows: The FFT window array memory is provided by the INO. Three common and |
||||
* useful window functions, plus no window, can be filled into the array by calling |
||||
* one of the following: |
||||
* windowFunction(AudioWindowNone); |
||||
* windowFunction(AudioWindowHanning4096); |
||||
* windowFunction(AudioWindowKaiser4096); |
||||
* windowFunction(AudioWindowBlackmanHarris4096); |
||||
* See: https://en.wikipedia.org/wiki/Window_function
|
||||
* |
||||
* 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 |
||||
* 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 |
||||
* tends to compensate for the attenuation at the window edges when doing a sequence |
||||
* of FFT's. For that reason there can be a new FFT result every 2048 time |
||||
* series data points. |
||||
* |
||||
* Scaling: |
||||
* Full scale for floating point DSP is a nebulous concept. Normally the |
||||
* full scale is -1.0 to +1.0. This is an unscaled FFT and for a sine |
||||
* wave centered in frequency on a bin and of FS amplitude, the power |
||||
* at that center bin will grow by 4096^2/4 = about 4 million without windowing. |
||||
* Windowing loss cuts this down. The RMS level can growwithout windowing to |
||||
* 4096. The dBFS has been scaled to make this max value 0 dBFS by |
||||
* removing 66.2 dB. With floating point, the dynamic range is maintained |
||||
* no matter how it is scaled, but this factor needs to be considered |
||||
* when building the INO. |
||||
*/ |
||||
/* 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 */ |
||||
|
||||
#ifndef analyze_fft4096_iqem_h_ |
||||
#define analyze_fft4096_iqem_h_ |
||||
|
||||
// *************** TEENSY 4.X ONLY ****************
|
||||
#if defined(__IMXRT1062__) |
||||
|
||||
#include "Arduino.h" |
||||
#include "AudioStream_F32.h" |
||||
#include "arm_math.h" |
||||
#include "mathDSP_F32.h" |
||||
#include "arm_const_structs.h" |
||||
|
||||
#define FFT_RMS 0 |
||||
#define FFT_POWER 1 |
||||
#define FFT_DBFS 2 |
||||
|
||||
#define NO_WINDOW 0 |
||||
#define AudioWindowNone 0 |
||||
#define AudioWindowHanning4096 1 |
||||
#define AudioWindowKaiser4096 2 |
||||
#define AudioWindowBlackmanHarris4096 3 |
||||
|
||||
class AudioAnalyzeFFT4096_IQEM_F32 : public AudioStream_F32 { |
||||
//GUI: inputs:2, outputs:0 //this line used for automatic generation of GUI node
|
||||
//GUI: shortName:FFT4096IQem
|
||||
|
||||
public: |
||||
AudioAnalyzeFFT4096_IQEM_F32 // Without sumsq in call for averaging
|
||||
(float32_t* _pOutput, float32_t* _pWindow, float32_t* _pFFT_buffer) : |
||||
AudioStream_F32(2, inputQueueArray) { |
||||
pOutput = _pOutput; |
||||
pWindow = _pWindow; |
||||
pFFT_buffer = _pFFT_buffer; |
||||
pSumsq = NULL; |
||||
// Teensy4 core library has the right files for new FFT
|
||||
// arm CMSIS library has predefined structures of type arm_cfft_instance_f32
|
||||
Sfft = arm_cfft_sR_f32_len4096; // This is one of the structures
|
||||
useHanningWindow(); |
||||
} |
||||
|
||||
AudioAnalyzeFFT4096_IQEM_F32 // Constructor to include sumsq power averaging.
|
||||
(float32_t* _pOutput, float32_t* _pWindow, float32_t* _pFFT_buffer, |
||||
float32_t* _pSumsq) : |
||||
AudioStream_F32(2, inputQueueArray) { |
||||
pOutput = _pOutput; |
||||
pWindow = _pWindow; |
||||
pFFT_buffer = _pFFT_buffer; |
||||
pSumsq = _pSumsq; |
||||
// Teensy4 core library has the right files for new FFT
|
||||
// arm CMSIS library has predefined structures of type arm_cfft_instance_f32
|
||||
Sfft = arm_cfft_sR_f32_len4096; // This is one of the structures
|
||||
useHanningWindow(); |
||||
} |
||||
|
||||
// There is no varient for "settings," as blocks other than 128 are
|
||||
// not supported and, nothing depends on sample rate so we don't need that.
|
||||
|
||||
// Returns true when output data is available.
|
||||
bool available() { |
||||
#if defined(__IMXRT1062__) |
||||
if (outputflag == true) { |
||||
outputflag = false; // No double returns
|
||||
return true; |
||||
} |
||||
return false; |
||||
#else |
||||
// Don't know how you got this far, but....
|
||||
Serial.println("Teensy 3.x NOT SUPPORTED"); |
||||
return false; |
||||
#endif |
||||
} |
||||
|
||||
// Returns a single bin output
|
||||
float read(unsigned int binNumber) { |
||||
if (binNumber>4095 || binNumber<0) return 0.0; |
||||
return *(pOutput + binNumber); |
||||
} |
||||
|
||||
// Return sum of several bins. Normally use with power output.
|
||||
// This produces the equivalent of bigger bins.
|
||||
float read(unsigned int binFirst, unsigned int binLast) { |
||||
if (binFirst > binLast) { |
||||
unsigned int tmp = binLast; |
||||
binLast = binFirst; |
||||
binFirst = tmp; |
||||
} |
||||
if (binFirst > 4095) return 0.0; |
||||
if (binLast > 4095) binLast = 4095; |
||||
float sum = 0; |
||||
do { |
||||
sum += *(pOutput + binFirst++); |
||||
} while (binFirst <= binLast); |
||||
return sum; |
||||
} |
||||
|
||||
// Sets None, Hann, or Blackman-Harris window with no parameter
|
||||
int windowFunction(int _wNum) { |
||||
wNum = _wNum; |
||||
if(wNum == AudioWindowKaiser4096) |
||||
return -1; // Kaiser needs the kdb
|
||||
windowFunction(wNum, 0.0f); |
||||
return 0; |
||||
} |
||||
|
||||
int windowFunction(int _wNum, float _kdb) { // Kaiser case
|
||||
float kd; |
||||
wNum = _wNum; |
||||
if (wNum == AudioWindowKaiser4096) { |
||||
if(_kdb<20.0f) |
||||
kd = 20.0f; |
||||
else |
||||
kd = _kdb; |
||||
useKaiserWindow(kd); |
||||
} |
||||
else if (wNum == AudioWindowBlackmanHarris4096) |
||||
useBHWindow(); |
||||
else |
||||
useHanningWindow(); // Default
|
||||
return 0; |
||||
} |
||||
|
||||
// Number of FFT averaged in the output
|
||||
void setNAverage(int _nAverage) { |
||||
if(!(pSumsq==NULL)) // We can average because we have memory.
|
||||
nAverage = _nAverage; |
||||
} |
||||
|
||||
// Output RMS (default), power or dBFS (FFT_RMS, FFT_POWER, FFT_DBFS)
|
||||
void setOutputType(int _type) { |
||||
outputType = _type; |
||||
} |
||||
|
||||
// xAxis, bit 0 left/right; bit 1 low to high; default 0X03
|
||||
void setXAxis(uint8_t _xAxis) { |
||||
xAxis = _xAxis; |
||||
} |
||||
|
||||
virtual void update(void); |
||||
|
||||
private: |
||||
float32_t *pOutput, *pWindow, *pFFT_buffer; |
||||
float32_t *pSumsq; |
||||
int wNum = AudioWindowHanning4096; |
||||
uint8_t state = 0; |
||||
bool outputflag = false; |
||||
audio_block_f32_t *inputQueueArray[2]; |
||||
audio_block_f32_t *blocklist_i[32]; |
||||
audio_block_f32_t *blocklist_q[32]; |
||||
// For T4.x
|
||||
// const static arm_cfft_instance_f32 arm_cfft_sR_f32_len1024;
|
||||
arm_cfft_instance_f32 Sfft; |
||||
int outputType = FFT_RMS; //Same type as I16 version init
|
||||
int count = 0; |
||||
int nAverage = 1; |
||||
uint8_t xAxis = 0x03; |
||||
|
||||
// The Hann window is a good all-around window
|
||||
// This can be used with zero-bias frequency interpolation.
|
||||
// pWidow points to INO supplied buffer. 4096 for now. MAKE 2048 <<<<<<<<<<<<<<<<
|
||||
void useHanningWindow(void) { |
||||
if(!pWindow) return; // No placefor a window
|
||||
for (int i=0; i < 2048; i++) { |
||||
// 2*PI/4095 = 0.00153435538
|
||||
*(pWindow + i) = 0.5*(1.0 - cosf(0.00153435538f*(float)i)); |
||||
} |
||||
} |
||||
|
||||
// Blackman-Harris produces a first sidelobe more than 90 dB down.
|
||||
// The price is a bandwidth of about 2 bins. Very useful at times.
|
||||
void useBHWindow(void) { |
||||
if(!pWindow) return; |
||||
for (int i=0; i < 2048; i++) { |
||||
float kx = 0.00153435538f; // 2*PI/4095
|
||||
int ix = (float) i; |
||||
*(pWindow + i) = 0.35875 - |
||||
0.48829*cosf( kx*ix) + |
||||
0.14128*cosf(2.0f*kx*ix) - |
||||
0.01168*cosf(3.0f*kx*ix); |
||||
} |
||||
} |
||||
|
||||
/* The windowing function here is that of James Kaiser. This has a number
|
||||
* of desirable features. The sidelobes drop off as the frequency away from a transition. |
||||
* Also, the tradeoff of sidelobe level versus cutoff rate is variable. |
||||
* Here we specify it in terms of kdb, the highest sidelobe, in dB, next to a sharp cutoff. For |
||||
* calculating the windowing vector, we need a parameter beta, found as follows: |
||||
*/ |
||||
void useKaiserWindow(float kdb) { |
||||
float32_t beta, kbes, xn2; |
||||
mathDSP_F32 mathEqualizer; // For Bessel function
|
||||
|
||||
if(!pWindow) return; |
||||
|
||||
if (kdb < 20.0f) |
||||
beta = 0.0; |
||||
else |
||||
beta = -2.17+0.17153*kdb-0.0002841*kdb*kdb; // Within a dB or so
|
||||
|
||||
// Note: i0f is the fp zero'th order modified Bessel function (see mathDSP_F32.h)
|
||||
kbes = 1.0f / mathEqualizer.i0f(beta); // An additional derived parameter used in loop
|
||||
for (int n=0; n<2048; n++) { |
||||
xn2 = 0.5f+(float32_t)n; |
||||
// 4/(4095^2) = 2.3853504E-7
|
||||
xn2 = 2.3853504E-7*xn2*xn2; |
||||
*(pWindow + 2047 - n) = kbes*(mathEqualizer.i0f(beta*sqrtf(1.0-xn2))); |
||||
} |
||||
} |
||||
}; |
||||
#endif |
||||
#endif |
@ -0,0 +1,94 @@ |
||||
// TestFFT2048iqEM.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
|
||||
// EXTERNAL MEMORY FFT
|
||||
// Public Domain
|
||||
|
||||
#include "OpenAudio_ArduinoLibrary.h" |
||||
#include "AudioStream_F32.h" |
||||
|
||||
// Memory for IQ FFT
|
||||
float32_t fftOutput[4096]; // Array to allow fftBuffer[] to be available for new in data
|
||||
float32_t window[2048]; // Half size window storage
|
||||
float32_t fftBuffer[8192]; // Used for FFT, 4096 real, 4096 imag, interleaved
|
||||
float32_t sumsq[4096]; // Required if power averaging is being done
|
||||
|
||||
int jj; |
||||
|
||||
// GUItool: begin automatically generated code
|
||||
AudioSynthSineCosine_F32 sine_cos1; //xy=76,532
|
||||
// Optional
|
||||
// (float32_t* _pOutput, float32_t* _pWindow, float32_t* _pFFT_buffer, float32_t* _pSumsq)
|
||||
//AudioAnalyzeFFT4096_IQEM_F32 FFT4096iqEM1(fftOutput, window, fftBuffer); //xy=243,532
|
||||
AudioAnalyzeFFT4096_IQEM_F32 FFT4096iqEM1(fftOutput, window, fftBuffer, sumsq); // w/ power ave
|
||||
AudioOutputI2S_F32 audioOutI2S1; //xy=246,591
|
||||
AudioConnection_F32 patchCord1(sine_cos1, 0, FFT4096iqEM1, 0); |
||||
AudioConnection_F32 patchCord2(sine_cos1, 1, FFT4096iqEM1, 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("FFT4096IQem Test"); |
||||
|
||||
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); |
||||
|
||||
// elect the output format, FFT_RMS, FFT_POWER, or FFT_DBFS
|
||||
FFT4096iqEM1.setOutputType(FFT_DBFS); |
||||
|
||||
// Select the wndow function, designed by FFT object
|
||||
//FFT4096iqEM1.windowFunction(AudioWindowNone);
|
||||
//FFT4096iqEM1.windowFunction(AudioWindowHanning4096);
|
||||
//FFT4096iqEM1.windowFunction(AudioWindowKaiser4096, 55.0f);
|
||||
FFT4096iqEM1.windowFunction(AudioWindowBlackmanHarris4096); |
||||
|
||||
// Uncomment to Serial print window function
|
||||
// for (int i=0; i<2048; i++) Serial.println(*(window+i), 7);
|
||||
|
||||
// xAxis, bit 0 left/right; bit 1 low to high; default 0X03
|
||||
FFT4096iqEM1.setXAxis(0X01); |
||||
|
||||
// In order to average powers, a buffer for sumsq[4096] must be
|
||||
// globally declared and that pointer, sumsq, set as the last
|
||||
// parameter in the object creation. Then the following will
|
||||
// cause averaging of 4 powers:
|
||||
FFT4096iqEM1.setNAverage(20); |
||||
|
||||
jj = 0; // This is todelay data gathering to get steady state
|
||||
} |
||||
|
||||
void loop(void) { |
||||
static bool doPrint=true; |
||||
float *pPwr; |
||||
|
||||
delay(10); |
||||
|
||||
// Print output, once
|
||||
if( FFT4096iqEM1.available() && doPrint ) { |
||||
if(jj++ < 3)return; |
||||
for(int i=0; i<4096; i++) |
||||
{ |
||||
Serial.print((int)((float32_t)i * 44100.0/4096.0)); |
||||
Serial.print(" "); |
||||
Serial.println(*(fftOutput + i), 8 ); |
||||
} |
||||
doPrint = false; |
||||
} |
||||
Serial.print(" Audio MEM Float32 Peak: "); |
||||
Serial.println(AudioMemoryUsageMax_F32()); |
||||
delay(500); |
||||
} |
Loading…
Reference in new issue