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123 lines
4.6 KiB
123 lines
4.6 KiB
/* radioModulatedGenerator_F32.cpp
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*
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* RadioModulatedGenerator_F32 class - See .h file for information.
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* Copyright (c) 2021 Bob Larkin Created: 15 April 2021
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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 and this permission notice shall be included in all
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* 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 THE
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* SOFTWARE.
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*/
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#include "radioModulatedGenerator_F32.h"
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// 513 values of the sine wave in a float array:
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#include "sinTable512_f32.h"
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void radioModulatedGenerator_F32::update(void) {
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audio_block_f32_t *inAmpl, *inPhaseFreq;
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audio_block_f32_t *outBlockI, *outBlockQ;
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uint16_t index, i;
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float32_t a, b, deltaPhase, phaseC, amSig;
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// Input 0 is for amplitude modulation.
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inAmpl = NULL;
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if(doAM) {
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inAmpl = AudioStream_F32::receiveReadOnly_f32(0);
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if (!inAmpl) return;
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}
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// Input 1 is for phase or frequency modulation.
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inPhaseFreq = NULL;
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if(doPM || doFM) {
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inPhaseFreq = AudioStream_F32::receiveReadOnly_f32(1);
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if (!inPhaseFreq) {
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if(doAM) AudioStream_F32::release(inAmpl);
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return;
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}
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}
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outBlockI = AudioStream_F32::allocate_f32(); // Output blocks
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if (!outBlockI) {
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if(doAM) AudioStream_F32::release(inAmpl);
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if(doPM || doFM) AudioStream_F32::release(inPhaseFreq);
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return;
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}
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outBlockQ = NULL;
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if(bothIQ) {
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outBlockQ = AudioStream_F32::allocate_f32();
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if (!outBlockQ) {
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if(doAM) AudioStream_F32::release(inAmpl);
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if(doPM || doFM) AudioStream_F32::release(inPhaseFreq);
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AudioStream_F32::release(outBlockI);
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return;
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}
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}
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for (i=0; i < block_length; i++) {
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if(doPM) // Phase in inPhaseFreq->data[i] is scaled for (0.0, 2*PI)
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phaseS += (phaseIncrement0 + K512ON2PI*inPhaseFreq->data[i]);
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else if(doFM)
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phaseS += kp*(freq + deviationFMScale*inPhaseFreq->data[i]); // kp=512.0/sample_rate_Hz
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else
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phaseS += phaseIncrement0; // No PM or FM alteration to carrier phase
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while (phaseS > 512.0f)
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phaseS -= 512.0f;
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while (phaseS < 0.0f)
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phaseS += 512.0f;
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index = (uint16_t) phaseS; // Does adding 0.5 here cut errors? <<<<<<<<<<<<<<<<<<
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deltaPhase = phaseS -(float32_t) index;
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/* Read two nearest values of input value from the sin table */
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a = sinTable512_f32[index];
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b = sinTable512_f32[index+1];
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if(doAM) {
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amSig = 1.0f + inAmpl->data[i];
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if(amSig<0.0f)
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amSig = 0.0f; // Common def of AM going back to vacuum tubes
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outBlockI->data[i] = amplitude_pk*amSig*(a + 0.001953125*(b-a)*deltaPhase); /* Linear interpolation process */
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}
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else
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outBlockI->data[i] = amplitude_pk*(a + 0.001953125*(b-a)*deltaPhase);
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if(bothIQ) {
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/* Shift forward phaseQ_I and get cos. First, the calculation of index of the table */
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phaseC = phaseS + phaseQ_I;
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while (phaseC > 512.0f)
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phaseC -= 512.0f;
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while (phaseC < 0.0f)
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phaseC += 512.0f;
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index = (uint16_t) phaseC;
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deltaPhase = phaseC -(float32_t) index;
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/* Read two nearest values of input value from the sin table */
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a = sinTable512_f32[index];
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b = sinTable512_f32[index+1];
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if(doAM) // amSig from above
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outBlockQ->data[i] = amplitudeQ_I*amplitude_pk*amSig*(a + 0.001953125*(b-a)*deltaPhase);
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else
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outBlockQ->data[i] = amplitudeQ_I*amplitude_pk*(a + 0.001953125*(b-a)*deltaPhase);
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}
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}
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if(doAM) AudioStream_F32::release(inAmpl);
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if(doPM || doFM) AudioStream_F32::release(inPhaseFreq);
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AudioStream_F32::transmit(outBlockI, 0);
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AudioStream_F32::release (outBlockI);
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if(bothIQ) {
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AudioStream_F32::transmit(outBlockQ, 1);
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AudioStream_F32::release (outBlockQ);
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}
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}
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