118 lines
2.5 KiB
C++
118 lines
2.5 KiB
C++
/*
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AudioOutputPWM
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Base class for the RP2040 PWM audio
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Copyright (C) 2023 Earle F. Philhower, III
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#if defined(ARDUINO_ARCH_RP2040)
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#include <Arduino.h>
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#include "AudioOutputPWM.h"
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AudioOutputPWM::AudioOutputPWM(long sampleRate, pin_size_t data) : pwm(data, false) {
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pwmOn = false;
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mono = false;
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bps = 16;
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channels = 2;
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hertz = sampleRate;
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doutPin = data;
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SetGain(1.0);
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pwm.setStereo(true);
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}
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AudioOutputPWM::~AudioOutputPWM() {
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stop();
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}
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bool AudioOutputPWM::SetRate(int hz) {
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this->hertz = hz;
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if (pwmOn) {
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pwm.setFrequency(hz);
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}
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return true;
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}
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bool AudioOutputPWM::SetBitsPerSample(int bits) {
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if ( (bits != 16) && (bits != 8) ) return false;
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this->bps = bits;
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return true;
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}
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bool AudioOutputPWM::SetChannels(int channels) {
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if ( (channels < 1) || (channels > 2) ) return false;
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this->channels = channels;
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return true;
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}
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bool AudioOutputPWM::SetOutputModeMono(bool mono) {
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this->mono = mono;
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return true;
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}
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bool AudioOutputPWM::begin() {
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if (!pwmOn) {
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pwm.setPin(doutPin);
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pwm.begin(hertz);
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}
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pwmOn = true;
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SetRate(hertz); // Default
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return true;
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}
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bool AudioOutputPWM::ConsumeSample(int16_t sample[2]) {
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if (!pwmOn)
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return false;
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int16_t ms[2];
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ms[0] = sample[0];
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ms[1] = sample[1];
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MakeSampleStereo16( ms );
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if (this->mono) {
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// Average the two samples and overwrite
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int32_t ttl = ms[LEFTCHANNEL] + ms[RIGHTCHANNEL];
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ms[LEFTCHANNEL] = ms[RIGHTCHANNEL] = (ttl>>1) & 0xffff;
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}
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ms[LEFTCHANNEL] = Amplify(ms[LEFTCHANNEL]);
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ms[RIGHTCHANNEL] = Amplify(ms[RIGHTCHANNEL]);
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if (pwm.available()) {
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pwm.write((int16_t) ms[0]);
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pwm.write((int16_t) ms[1]);
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return true;
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} else {
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return false;
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}
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}
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void AudioOutputPWM::flush() {
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pwm.flush();
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}
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bool AudioOutputPWM::stop() {
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if (!pwmOn)
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return false;
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pwm.end();
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pwmOn = false;
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return true;
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}
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#endif
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