/* * analyze_fft1024_iq_F32.cpp Assembled by Bob Larkin 3 Mar 2021 * Rev 6 Mar 2021 - Added setXAxis() * * Converted to F32 floating point input and also extended * for complex I and Q inputs * * Adapted all I/O to be F32 floating point for OpenAudio_ArduinoLibrary * * Future: Add outputs for I & Q FFT x2 for overlapped FFT * * Windowing None, Hann, Kaiser and Blackman-Harris. * * Conversion Copyright (c) 2021 Bob Larkin * Same MIT license as PJRC: * * 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. */ #include #include "analyze_fft1024_iq_F32.h" // Note: Suppports block size of 128 only. Very "built in." // Move audio data from audio_block_f32_t to the interleaved FFT instance buffer. static void copy_to_fft_buffer1(void *destination, const void *sourceI, const void *sourceQ) { const float *srcI = (const float *)sourceI; const float *srcQ = (const float *)sourceQ; float *dst = (float *)destination; // part of fft_buffer array. 256 floats per call for (int i=0; i < 128; i++) { *dst++ = *srcI++; // real sample, interleave *dst++ = *srcQ++; // imag } } static void apply_window_to_fft_buffer1(void *fft_buffer, const void *window) { float *buf = (float *)fft_buffer; // 0th entry is real (do window) 1st is imag const float *win = (float *)window; for (int i=0; i < 1024; i++) { buf[2*i] *= *win; // real buf[2*i + 1] *= *win++; // imag } } void AudioAnalyzeFFT1024_IQ_F32::update(void) { audio_block_f32_t *block_i,*block_q; int ii; block_i = receiveReadOnly_f32(0); if (!block_i) return; block_q = receiveReadOnly_f32(1); if (!block_q) { release(block_i); return; } // Here with two new blocks of data switch (state) { case 0: blocklist_i[0] = block_i; blocklist_q[0] = block_q; state = 1; break; case 1: blocklist_i[1] = block_i; blocklist_q[1] = block_q; state = 2; break; case 2: blocklist_i[2] = block_i; blocklist_q[2] = block_q; state = 3; break; case 3: blocklist_i[3] = block_i; blocklist_q[3] = block_q; state = 4; break; case 4: blocklist_i[4] = block_i; blocklist_q[4] = block_q; state = 5; break; case 5: blocklist_i[5] = block_i; blocklist_q[5] = block_q; state = 6; break; case 6: blocklist_i[6] = block_i; blocklist_q[6] = block_q; state = 7; break; case 7: blocklist_i[7] = block_i; blocklist_q[7] = block_q; copy_to_fft_buffer1(fft_buffer+0x000, blocklist_i[0]->data, blocklist_q[0]->data); copy_to_fft_buffer1(fft_buffer+0x100, blocklist_i[1]->data, blocklist_q[1]->data); copy_to_fft_buffer1(fft_buffer+0x200, blocklist_i[2]->data, blocklist_q[2]->data); copy_to_fft_buffer1(fft_buffer+0x300, blocklist_i[3]->data, blocklist_q[3]->data); copy_to_fft_buffer1(fft_buffer+0x400, blocklist_i[4]->data, blocklist_q[4]->data); copy_to_fft_buffer1(fft_buffer+0x500, blocklist_i[5]->data, blocklist_q[5]->data); copy_to_fft_buffer1(fft_buffer+0x600, blocklist_i[6]->data, blocklist_q[6]->data); copy_to_fft_buffer1(fft_buffer+0x700, blocklist_i[7]->data, blocklist_q[7]->data); if (pWin) apply_window_to_fft_buffer1(fft_buffer, window); #if defined(__IMXRT1062__) // Teensyduino core for T4.x supports arm_cfft_f32 // arm_cfft_f32 (const arm_cfft_instance_f32 *S, float32_t *p1, uint8_t ifftFlag, uint8_t bitReverseFlag) arm_cfft_f32(&Sfft, fft_buffer, 0, 1); #else // For T3.x go back to old (deprecated) style arm_cfft_radix4_f32(&fft_inst, fft_buffer); #endif count++; for (int i = 0; i < 512; i++) { // From complex FFT the "negative frequencies" are mirrors of the frequencies above fs/2. So, we get // frequencies from 0 to fs by re-arranging the coefficients. These are powers (not Volts) // See DD4WH SDR float ss0 = fft_buffer[2 * i] * fft_buffer[2 * i] + fft_buffer[2 * i + 1] * fft_buffer[2 * i + 1]; float ss1 = fft_buffer[2 * (i + 512)] * fft_buffer[2 * (i + 512)] + fft_buffer[2 * (i + 512) + 1] * fft_buffer[2 * (i + 512) + 1]; if(count==1) { // Starting new average sumsq[i+512] = ss0; sumsq[i] = ss1; } else if (count <= nAverage) { // Adding on to average sumsq[i+512] += ss0; sumsq[i] += ss1; } } if (count >= nAverage) { // Average is finished count = 0; float inAf = 1.0f/(float)nAverage; for (int i=0; i < 1024; i++) { // xAxis, bit 0 left/right; bit 1 low to high if(xAxis & 0X02) ii = i; else ii = i^512; if(xAxis & 0X01) ii = (1023 - ii); if(outputType==FFT_RMS) output[i] = sqrtf(inAf*sumsq[ii]); else if(outputType==FFT_POWER) output[i] = inAf*sumsq[ii]; else if(outputType==FFT_DBFS) output[i] = 10.0f*log10f(inAf*sumsq[ii])-54.1854f; // Scaled to FS sine wave else output[i] = 0.0f; } } // end of Average is Finished outputflag = true; release(blocklist_i[0]); release(blocklist_q[0]); release(blocklist_i[1]); release(blocklist_q[1]); release(blocklist_i[2]); release(blocklist_q[2]); release(blocklist_i[3]); release(blocklist_q[3]); blocklist_i[0] = blocklist_i[4]; blocklist_i[1] = blocklist_i[5]; blocklist_i[2] = blocklist_i[6]; blocklist_i[3] = blocklist_i[7]; blocklist_q[0] = blocklist_q[4]; blocklist_q[1] = blocklist_q[5]; blocklist_q[2] = blocklist_q[6]; blocklist_q[3] = blocklist_q[7]; state = 4; break; // From case 7 } // End of switch & case 7 } // End update()