Play sound sequences asynchronously (#122)

* buzzer sequences: first draft, does not work on hardware yet (but in simulator)

* buzzer sequences: add changes to movement.c

* buzzer sequences: add demo face to Makefile

* buzzer sequences: fix problem of interrupted sounds. Add logic for repeating sub sequences. Tidy up (move logic to watch_buzzer files, remove buzzer_demo_face)

* buzzer sequences: tidy up even more

* buzzer sequences: disable registering a 32 Hz tick callback for watch faces, so it will be used exclusively by the buzzer sequences functionality

* buzzer sequences: add callback slot functionality to watch_rtc and make watch_buzzer use it. Switch internal buzzer sequences tick frequency to 64 Hz. Revert changes to movement.c

* buzzer sequences: fix parameter sanity check in watch_rtc code

* buzzer sequences/watch_rtc: optimize calling tick callbacks in RTC_Handler

* buzzer sequences/watch_rtc: fix error in calling callback functions

* buzzer sequences: revert changes to watch_rtc logic. Instead, use TC3 as the source for timing the sound sequences.

* buzzer sequences: fix frequency of callback

* buzzer sequences: integrate changes from PR #162 (set both CCBUF and PERFBUF for correct buzzer tone)

1 files changed, 23 insertions, 0 deletions

diff --git a/watch-library/shared/watch/watch_buzzer.h b/watch-library/shared/watch/watch_buzzer.h
index 1b5d197c..7ba9a52e 100644
--- a/watch-library/shared/watch/watch_buzzer.h
+++ b/watch-library/shared/watch/watch_buzzer.h
@@ -160,5 +160,28 @@ void watch_buzzer_play_note(BuzzerNote note, uint16_t duration_ms);
 /// @brief An array of periods for all the notes on a piano, corresponding to the names in BuzzerNote.
 extern const uint16_t NotePeriods[108];
 
+/** @brief Plays the given sequence of notes in a non-blocking way.
+  * @param note_sequence A pointer to the sequence of buzzer note & duration tuples, ending with a zero. A simple
+  *        RLE logic is implemented: a negative number instead of a buzzer note means that the sequence
+  *        is rewound by the given number of notes. The byte following a negative number determines the number
+  *        of loops. I.e. if you want to repeat the last three notes of the sequence one time, you should provide 
+  *        the tuple -3, 1. The repeated notes must not contain any other repeat markers, or you will end up with 
+  *        an eternal loop.
+  * @param callback_on_end A pointer to a callback function to be invoked when the sequence has finished playing.
+  * @note This function plays the sequence asynchronously, so the UI will not be blocked. 
+  *       Hint: It is not possible to play the lowest note BUZZER_NOTE_A1 (55.00 Hz). The note is represented by a 
+  *       zero byte, which is used here as the end-of-sequence marker. But hey, a frequency that low cannot be
+  *       played properly by the watch's buzzer, anyway.
+  */
+void watch_buzzer_play_sequence(int8_t *note_sequence, void (*callback_on_end)(void));
+
+/** @brief Aborts a playing sequence.
+  */
+void watch_buzzer_abort_sequence(void);
+
+#ifndef __EMSCRIPTEN__
+void TC3_Handler(void);
+#endif
+
 /// @}
 #endif