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Arduino/libraries/Zumo/ZumoBuzzer.h

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/*! \file ZumoBuzzer.h
*
* See the ZumoBuzzer class reference for more information about this library.
*
* \class ZumoBuzzer ZumoBuzzer.h
* \brief Play beeps and music with buzzer
*
* The ZumoBuzzer library allows various sounds to be played through the buzzer
* on the Zumo Shield, from simple beeps to complex tunes. The buzzer is
* controlled using a PWM output of Timer 2 (on the Arduino Uno and other
* ATmega328/168 boards) or Timer 4 (on the Arduino Leonardo and other
* ATmega32U4 boards), so it will conflict with any other uses of that timer.
*
* Note durations are timed using a timer overflow interrupt
* (`TIMER2_OVF`/`TIMER4_OVF`), which will briefly interrupt execution of your
* main program at the frequency of the sound being played. In most cases, the
* interrupt-handling routine is very short (several microseconds). However,
* when playing a sequence of notes in `PLAY_AUTOMATIC` mode (the default mode)
* with the `play()` command, this interrupt takes much longer than normal
* (perhaps several hundred microseconds) every time it starts a new note. It is
* important to take this into account when writing timing-critical code.
*
* The ZumoBuzzer library is fully compatible with the OrangutanBuzzer functions
* in the [Pololu AVR C/C++ Library](http://www.pololu.com/docs/0J18), so any
* sequences and melodies written for OrangutanBuzzer functions will also work
* with the equivalent ZumoBuzzer functions.
*/
#ifndef ZumoBuzzer_h
#define ZumoBuzzer_h
#define PLAY_AUTOMATIC 0
#define PLAY_CHECK 1
// n
// Equal Tempered Scale is given by f = f * a
// n o
//
// where f is chosen as A above middle C (A4) at f = 440 Hz
// o o
// and a is given by the twelfth root of 2 (~1.059463094359)
/*! \anchor note_macros
*
* \name Note Macros
* \a x specifies the octave of the note
* @{
*/
#define NOTE_C(x) ( 0 + (x)*12)
#define NOTE_C_SHARP(x) ( 1 + (x)*12)
#define NOTE_D_FLAT(x) ( 1 + (x)*12)
#define NOTE_D(x) ( 2 + (x)*12)
#define NOTE_D_SHARP(x) ( 3 + (x)*12)
#define NOTE_E_FLAT(x) ( 3 + (x)*12)
#define NOTE_E(x) ( 4 + (x)*12)
#define NOTE_F(x) ( 5 + (x)*12)
#define NOTE_F_SHARP(x) ( 6 + (x)*12)
#define NOTE_G_FLAT(x) ( 6 + (x)*12)
#define NOTE_G(x) ( 7 + (x)*12)
#define NOTE_G_SHARP(x) ( 8 + (x)*12)
#define NOTE_A_FLAT(x) ( 8 + (x)*12)
#define NOTE_A(x) ( 9 + (x)*12)
#define NOTE_A_SHARP(x) (10 + (x)*12)
#define NOTE_B_FLAT(x) (10 + (x)*12)
#define NOTE_B(x) (11 + (x)*12)
/*! \brief silences buzzer for the note duration */
#define SILENT_NOTE 0xFF
/*! \brief frequency bit that indicates Hz/10<br>
* e.g. \a frequency = `(445 | DIV_BY_10)` gives a frequency of 44.5 Hz
*/
#define DIV_BY_10 (1 << 15)
/*! @} */
class ZumoBuzzer
{
public:
// constructor
ZumoBuzzer();
/*! \brief Plays the specified frequency for the specified duration.
*
* \param freq Frequency to play in Hz (or 0.1 Hz if the `DIV_BY_10` bit
* is set).
* \param duration Duration of the note in milliseconds.
* \param volume Volume of the note (0--15).
*
* The \a frequency argument must be between 40 Hz and 10 kHz. If the most
* significant bit of \a frequency is set, the frequency played is the value
* of the lower 15 bits of \a frequency in units of 0.1 Hz. Therefore, you can
* play a frequency of 44.5 Hz by using a \a frequency of `(DIV_BY_10 | 445)`.
* If the most significant bit of \a frequency is not set, the units for
* frequency are Hz. The \a volume argument controls the buzzer volume, with
* 15 being the loudest and 0 being the quietest. A \a volume of 15 supplies
* the buzzer with a 50% duty cycle PWM at the specified \a frequency.
* Lowering \a volume by one halves the duty cycle (so 14 gives a 25% duty
* cycle, 13 gives a 12.5% duty cycle, etc). The volume control is somewhat
* crude (especially on the ATmega328/168) and should be thought of as a bonus
* feature.
*
* This function plays the note in the background while your program continues
* to execute. If you call another buzzer function while the note is playing,
* the new function call will overwrite the previous and take control of the
* buzzer. If you want to string notes together, you should either use the
* `play()` function or put an appropriate delay after you start a note
* playing. You can use the `is_playing()` function to figure out when the
* buzzer is through playing its note or melody.
*
* ### Example ###
*
* ~~~{.ino}
* ZumoBuzzer buzzer;
*
* ...
*
* // play a 6 kHz note for 250 ms at a lower volume
* buzzer.playFrequency(6000, 250, 12);
*
* // wait for buzzer to finish playing the note
* while (buzzer.isPlaying());
*
* // play a 44.5 Hz note for 1 s at full volume
* buzzer.playFrequency(DIV_BY_10 | 445, 1000, 15);
* ~~~
*
* \warning \a frequency &times; \a duration / 1000 must be no greater than
0xFFFF (65535). This means you can't use a max duration of 65535 ms for
frequencies greater than 1 kHz. For example, the maximum duration you can
use for a frequency of 10 kHz is 6553 ms. If you use a duration longer than
this, you will produce an integer overflow that can result in unexpected
behavior.
*/
static void playFrequency(unsigned int freq, unsigned int duration,
unsigned char volume);
/*! \brief Plays the specified note for the specified duration.
*
* \param note Note to play (see \ref note_macros "Note Macros").
* \param duration Duration of the note in milliseconds.
* \param volume Volume of the note (0--15).
*
* The \a note argument is an enumeration for the notes of the equal tempered
* scale (ETS). See \ref note_macros "Note Macros" for more information. The
* \a volume argument controls the buzzer volume, with 15 being the loudest
* and 0 being the quietest. A \a volume of 15 supplies the buzzer with a 50%
* duty cycle PWM at the specified \a frequency. Lowering \a volume by one
* halves the duty cycle (so 14 gives a 25% duty cycle, 13 gives a 12.5% duty
* cycle, etc). The volume control is somewhat crude (especially on the
* ATmega328/168) and should be thought of as a bonus feature.
*
* This function plays the note in the background while your program continues
* to execute. If you call another buzzer function while the note is playing,
* the new function call will overwrite the previous and take control of the
* buzzer. If you want to string notes together, you should either use the
* `play()` function or put an appropriate delay after you start a note
* playing. You can use the `is_playing()` function to figure out when the
* buzzer is through playing its note or melody.
*/
static void playNote(unsigned char note, unsigned int duration,
unsigned char volume);
/*! \brief Plays the specified sequence of notes.
*
* \param sequence Char array containing a sequence of notes to play.
*
* If the play mode is `PLAY_AUTOMATIC` (default), the sequence of notes will
* play with no further action required by the user. If the play mode is
* `PLAY_CHECK`, the user will need to call `playCheck()` in the main loop to
* initiate the playing of each new note in the sequence. The play mode can be
* changed while the sequence is playing. The sequence syntax is modeled after
* the PLAY commands in GW-BASIC, with just a few differences.
*
* The notes are specified by the characters **C**, **D**, **E**, **F**,
* **G**, **A**, and **B**, and they are played by default as "quarter notes"
* with a length of 500 ms. This corresponds to a tempo of 120 beats/min.
* Other durations can be specified by putting a number immediately after the
* note. For example, C8 specifies C played as an eighth note, with half the
* duration of a quarter note. The special note **R** plays a rest (no sound).
* The sequence parser is case-insensitive and ignores spaces, which may be
* used to format your music nicely.
*
* Various control characters alter the sound:
* <table>
* <tr><th>Control character(s)</th><th>Effect</th></tr>
* <tr><td><strong>A--G</strong></td>
* <td>Specifies a note that will be played.</td></tr>
* <tr><td><strong>R</strong></td>
* <td>Specifies a rest (no sound for the duration of the note).</td></tr>
* <tr><td><strong>+</strong></strong> or <strong>#</strong> after a note</td>
* <td>Raises the preceding note one half-step.</td></tr>
* <tr><td><strong>-</strong> after a note</td>
* <td>Lowers the preceding note one half-step.</td></tr>
* <tr><td><strong>1--2000</strong> after a note</td>
* <td>Determines the duration of the preceding note. For example, C16
* specifies C played as a sixteenth note (1/16th the length of a
* whole note).</td></tr>
* <tr><td><strong>.</strong> after a note</td>
* <td>"Dots" the preceding note, increasing the length by 50%. Each
* additional dot adds half as much as the previous dot, so that "A.."
* is 1.75 times the length of "A".</td></tr>
* <tr><td><strong>></strong> before a note</td>
* <td>Plays the following note one octave higher.</td></tr>
* <tr><td><strong><</strong> before a note</td>
* <td>Plays the following note one octave lower.</td></tr>
* <tr><td><strong>O</strong> followed by a number</td>
* <td>Sets the octave. (default: **O4**)</td></tr>
* <tr><td><strong>T</strong> followed by a number</td>
* <td>Sets the tempo in beats per minute (BPM). (default: **T120**)</td></tr>
* <tr><td><strong>L</strong> followed by a number</td>
* <td>Sets the default note duration to the type specified by the number:
* 4 for quarter notes, 8 for eighth notes, 16 for sixteenth notes,
* etc. (default: **L4**)</td></tr>
* <tr><td><strong>V</strong> followed by a number</td>
* <td>Sets the music volume (0--15). (default: **V15**)</td></tr>
* <tr><td><strong>MS</strong></td>
* <td>Sets all subsequent notes to play play staccato -- each note is
* played for 1/2 of its allotted time, followed by an equal period of
* silence.</td></tr>
* <tr><td><strong>ML</strong></td>
* <td>Sets all subsequent notes to play legato -- each note is played for
* full length. This is the default setting.</td></tr>
* <tr><td><strong>!</strong></td>
* <td>Resets the octave, tempo, duration, volume, and staccato setting to
* their default values. These settings persist from one `play()` to the
* next, which allows you to more conveniently break up your music into
* reusable sections.</td></tr>
* </table>
*
* This function plays the string of notes in the background while your
* program continues to execute. If you call another buzzer function while the
* melody is playing, the new function call will overwrite the previous and
* take control of the buzzer. If you want to string melodies together, you
* should put an appropriate delay after you start a melody playing. You can
* use the `is_playing()` function to figure out when the buzzer is through
* playing the melody.
*
* ### Example ###
*
* ~~~{.ino}
* ZumoBuzzer buzzer;
*
* ...
*
* // play a C major scale up and back down:
* buzzer.play("!L16 V8 cdefgab>cbagfedc");
* while (buzzer.isPlaying());
*
* // the first few measures of Bach's fugue in D-minor
* buzzer.play("!T240 L8 agafaea dac+adaea fa<aa<bac#a dac#adaea f4");
* ~~~
*/
static void play(const char *sequence);
/*! \brief Plays the specified sequence of notes from program space.
*
* \param sequence Char array in program space containing a sequence of notes
* to play.
*
* A version of `play()` that takes a pointer to program space instead of RAM.
* This is desirable since RAM is limited and the string must be in program
* space anyway.
*
* ### Example ###
*
* ~~~{.ino}
* #include <avr/pgmspace.h>
*
* ZumoBuzzer buzzer;
* const char melody[] PROGMEM = "!L16 V8 cdefgab>cbagfedc";
*
* ...
*
* buzzer.playFromProgramSpace(melody);
* ~~~
*/
static void playFromProgramSpace(const char *sequence_p);
/*! \brief Controls whether `play()` sequence is played automatically or
* must be driven with `playCheck()`.
*
* \param mode Play mode (either `PLAY_AUTOMATIC` or `PLAY_CHECK`).
*
* This method lets you determine whether the notes of the `play()` sequence
* are played automatically in the background or are driven by the
* `play_check()` method. If \a mode is `PLAY_AUTOMATIC`, the sequence will
* play automatically in the background, driven by the timer overflow
* interrupt. The interrupt will take a considerable amount of time to execute
* when it starts the next note in the sequence playing, so it is recommended
* that you do not use automatic-play if you cannot tolerate being interrupted
* for more than a few microseconds. If \a mode is `PLAY_CHECK`, you can
* control when the next note in the sequence is played by calling the
* `play_check()` method at acceptable points in your main loop. If your main
* loop has substantial delays, it is recommended that you use automatic-play
* mode rather than play-check mode. Note that the play mode can be changed
* while the sequence is being played. The mode is set to `PLAY_AUTOMATIC` by
* default.
*/
static void playMode(unsigned char mode);
/*! \brief Starts the next note in a sequence, if necessary, in `PLAY_CHECK`
* mode.
*
* \return 0 if sequence is complete, 1 otherwise.
*
* This method only needs to be called if you are in `PLAY_CHECK` mode. It
* checks to see whether it is time to start another note in the sequence
* initiated by `play()`, and starts it if so. If it is not yet time to start
* the next note, this method returns without doing anything. Call this as
* often as possible in your main loop to avoid delays between notes in the
* sequence. This method returns 0 (false) if the melody to be played is
* complete, otherwise it returns 1 (true).
*/
static unsigned char playCheck();
/*! \brief Checks whether a note, frequency, or sequence is being played.
*
* \return 1 if the buzzer is current playing a note, frequency, or sequence;
* 0 otherwise.
*
* This method returns 1 (true) if the buzzer is currently playing a
* note/frequency or if it is still playing a sequence started by `play()`.
* Otherwise, it returns 0 (false). You can poll this method to determine when
* it's time to play the next note in a sequence, or you can use it as the
* argument to a delay loop to wait while the buzzer is busy.
*/
static unsigned char isPlaying();
/*! \brief Stops any note, frequency, or melody being played.
*
* This method will immediately silence the buzzer and terminate any
* note/frequency/melody that is currently playing.
*/
static void stopPlaying();
private:
// initializes timer for buzzer control
static void init2();
static void init();
};
#endif