Tone.cpp

/* Tone.cpp

  A Tone Generator Library

  Written by Brett Hagman

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library 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
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

#include "Arduino.h"

PinName g_lastPin = NC;
static stimer_t _timer;

// frequency (in hertz) and duration (in milliseconds).

void tone(uint8_t _pin, unsigned int frequency, unsigned long duration)
{
  PinName p = digitalPinToPinName(_pin);
  if(p != NC) {
    if((g_lastPin == NC) || (g_lastPin == p)) {
      _timer.pin = p;
      TimerPinInit(&_timer, frequency, duration);
      g_lastPin = p;
    }
  }
}


void noTone(uint8_t _pin)
{
  PinName p = digitalPinToPinName(_pin);
  if(p != NC) {
    TimerPinDeinit(&_timer);
    digitalWrite(_pin, 0);
    g_lastPin = NC;
  }
}