59 lines
2.2 KiB
C++
Executable file
59 lines
2.2 KiB
C++
Executable file
/* Audio Library for Teensy 3.X
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* Copyright (c) 2017, 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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#ifndef synth_pwm_h_
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#define synth_pwm_h_
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#include "Arduino.h"
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#include "AudioStream.h"
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#include "arm_math.h"
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class AudioSynthWaveformPWM : public AudioStream
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{
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public:
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AudioSynthWaveformPWM() : AudioStream(1, inputQueueArray), magnitude(0), elapsed(0) {}
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void frequency(float freq) {
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if (freq < 1.0) freq = 1.0;
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else if (freq > AUDIO_SAMPLE_RATE_EXACT/4) freq = AUDIO_SAMPLE_RATE_EXACT/4;
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//phase_increment = freq * (4294967296.0 / AUDIO_SAMPLE_RATE_EXACT);
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duration = (AUDIO_SAMPLE_RATE_EXACT * 65536.0 + freq) / (freq * 2.0);
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}
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void amplitude(float n) {
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if (n < 0) n = 0;
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else if (n > 1.0) n = 1.0;
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magnitude = n * 32767.0;
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}
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virtual void update(void);
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private:
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uint32_t duration; // samples per half cycle (when 50% duty) * 65536
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audio_block_t *inputQueueArray[1];
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int32_t magnitude;
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uint32_t elapsed;
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};
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#endif
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