If you want the turning off of the LED to be more responsive, change play_rtttl(char *p) to check after every note to see if the LED should be turned off. If you turn off the LED, return from the play_rtttl(char *p) function to end the melody.
If you want the turning off of the LED to be more responsive, change play_rtttl(char *p) to check after every note to see if the LED should be turned off. If you turn off the LED, return from the play_rtttl(char *p) function to end the melody.