#include #include #include #include #include static void tune(void) { buzzer_inv(); } void set_note(uint16_t note, uint8_t octave) { if(note != NOTE_PAUSE) { // bring buzzer to a state where inverting it creates sound buzzer_up(); // start timer with doubled frequency of tone we want to play start_timer(PRESCALE_8, note >> octave, tune); } else { // do nothing when paused stop_note(); } } void stop_note(void) { // turn buzzer off to save energy buzzer_off(); // we do not need the timer anymore stop_timer(); } void play_melody(uint16_t notes[], size_t len, uint8_t octave, int speed) { int pause = speed / 20; uint8_t length = 4; size_t i; for(i = 0; i < len; ++i) { if(notes[i] == MLDY_PAUSE) { // user defined pause ++i; wait_ms(notes[i]); } else if(notes[i] == MLDY_LENGTH) { // sets length for next tone ++i; length = notes[i]; } else { // play note set_note(notes[i], octave); test_stop_app(); wait_ms(speed * 4 / length); // pause after note stop_note(); test_stop_app(); wait_ms(pause); // reset length for next note length = 4; } } }