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Looped soundtracks

Now we will learn how to play a constant, looped soundtrack in the background.

Connect your last button to pin 7.

Open the looped-soundtracks sketch. Note that it has another button, and we added all of the following to support the new button:

  • int button3 = 7
  • Pb_switch sw3(100)
  • flag3
  • pinMode declaration in setup()
  • read instruction for flag3 inside the readinputs() function

Notice that there is a second tab open next to the looped-soundtracks sketch called mytunes.h. We are now defining all the songs in the mytunes.h, instead of in the main program file, and importing the contents of mytunes.h by typing #include "mytunes.h" at the top of the main sketch (similar to how we #include <Pinball.h>). Using multiple tabs is a way of keeping the code more readable.

Upload the code. Do you recognize the melody?

CHECKPOINT!

Inside setup(), we have:

spkr.loopstart(marionotes2, mariotimes2, 61);

This is another example of a looped event. The arrays marionotes2[] and mariotimes2[] have been defined inside mysongs.h. The command starts playing that melody in loop in the background. It is interrupted whenever a button is pressed, and each button plays a different melody (also defined in mysongs.h).

You can stop the loop track anytime by using loopstop(), just like for looped timed events.

Note the spkr.update() line inside writeoutputs().

The program has a new flag flag3, and new switch mysw3. Take a look at writeoutputs() function and try to figure out what they are doing.

CHECKPOINT!

Next we’ll put together everything we’ve learned so far!