Firmware/Marlin/speaker.h
2016-07-29 18:33:42 +01:00

91 lines
2.3 KiB
C++

/**
* Marlin 3D Printer Firmware
* Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
*
* Based on Sprinter and grbl.
* Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef __SPEAKER_H__
#define __SPEAKER_H__
#include "buzzer.h"
class Speaker: public Buzzer {
private:
typedef Buzzer super;
struct state_t {
tone_t tone;
uint16_t period;
uint16_t counter;
} state;
protected:
/**
* @brief Resets the state of the class
* @details Brings the class state to a known one.
*/
void reset() {
super::reset();
this->state.period = 0;
this->state.counter = 0;
}
public:
/**
* @brief Class constructor
*/
Speaker() {
this->reset();
}
/**
* @brief Loop function
* @details This function should be called at loop, it will take care of
* playing the tones in the queue.
*/
virtual void tick() {
if (!this->state.counter) {
if (this->buffer.isEmpty()) return;
this->reset();
this->state.tone = this->buffer.dequeue();
// Period is uint16, min frequency will be ~16Hz
this->state.period = 1000000UL / this->state.tone.frequency;
this->state.counter =
(this->state.tone.duration * 1000L) / this->state.period;
this->state.period >>= 1;
this->state.counter <<= 1;
} else {
const uint32_t now = micros();
static uint32_t next = now + this->state.period;
if (now >= next) {
--this->state.counter;
next = now + this->state.period;
if (this->state.tone.frequency > 0) this->invert();
}
}
}
};
#endif