analogWrite demo code

[jywarren]

Attempted addition of analogWrite interface to demo. Not tested yet.

[jywarren]

OK - I found that we can write to analog pins by treating them as digital pins, like:

board.digitalWrite(16, 1);

Where A0 is pin 14, A1 is pin 15, etc -- so + 14.

But I haven't been able to confirm that we can write to analog pins with analog values yet... need some hardware changes to get that working, as my current board has analog pins set up as digital ones for LEDs and I can't seem to get this to work:

Demo.board.analogWrite(15, 128);
Demo.board.analogWrite(1, 128); // or without adding 14, which should be the correct way

That should be the same as pwmWrite() according to this line, but neither seems to work.