Docs: Move toggleLED() and waitForButtonPress() examples.

These two examples from board-values.rst really belong in the
documentation for the functions they reference.

1 files changed, 26 insertions, 2 deletions

diff --git a/source/lang/api/waitforbuttonpress.rst b/source/lang/api/waitforbuttonpress.rst
index a5bd45c..0e0fbaf 100644
--- a/source/lang/api/waitforbuttonpress.rst
+++ b/source/lang/api/waitforbuttonpress.rst
@@ -1,16 +1,40 @@
+.. highlight:: cpp
+
 .. _lang-waitforbuttonpress:
 
 waitForButtonPress()
 ====================
 
-Wait for the board's built-in button (labeled BUT on the silkscreen)
-to be pressed, possibly with timeout.
+Wait for the board's built-in button to be pressed, possibly with
+timeout.  The button is labeled "BUT" on the board's silkscreen.  Its
+pin number is the constant :ref:`BOARD_BUTTON_PIN
+<lang-board-values-but>`.
 
 Library Documentation
 ---------------------
 
 .. doxygenfunction:: waitForButtonPress
 
+
+Example
+-------
+
+.. _lang-waitforbuttonpress-example:
+
+This example sets up the board's button pin as an input, then prints a
+message very time the button is pressed.
+
+::
+
+    void setup() {
+        pinMode(BOARD_BUTTON_PIN, INPUT);
+    }
+
+    void loop() {
+        waitForButtonPress();
+        SerialUSB.println("You pressed the button!");
+    }
+
 See Also
 --------