Merge branch 'master' into debug-serialusb.

Chose debug-serialusb version in cases of conflict.

Conflicts:
	libmaple/usb/usb_callbacks.c

1 files changed, 54 insertions, 0 deletions

diff --git a/docs/source/lang/cpp/booleanvariables.rst b/docs/source/lang/cpp/booleanvariables.rst
new file mode 100644
index 0000000..6051b8c
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+++ b/docs/source/lang/cpp/booleanvariables.rst
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+.. highlight:: cpp
+
+.. _lang-booleanvariables:
+
+Booleans
+========
+
+A **boolean** holds one of two values, :ref:`true
+<lang-constants-true>` or :ref:`false <lang-constants-false>`.  On a
+Maple, each boolean variable has type ``bool``.
+
+.. warning::
+
+   On an Arduino, the type ``boolean`` is also provided.  While the
+   Maple also has this type for compatibility, **its use is strongly
+   discouraged**.  The ``bool`` type is a standard part of C++, while
+   ``boolean`` is a non-standard extension that serves no purpose.
+
+Example
+-------
+
+::
+
+    int ledPin = 13;      // LED on pin 13
+    int switchPin = 12;   // momentary switch on 12, other side connected to ground
+
+    // running is a boolean variable:
+    bool running = false;
+
+    void setup() {
+      pinMode(ledPin, OUTPUT);
+      pinMode(switchPin, INPUT);
+      digitalWrite(switchPin, HIGH);      // turn on pullup resistor
+    }
+
+    void loop() {
+      if (digitalRead(switchPin) == LOW) {
+        // switch is pressed - pullup keeps pin high normally
+        delay(100);                        // delay to debounce switch
+        running = !running;                // toggle running variable
+        digitalWrite(ledPin, running)      // indicate via LED
+      }
+    }
+
+See also
+--------
+
+
+-  :ref:`Boolean constants <lang-constants-bool>`
+-  :ref:`Boolean operators <lang-boolean>`
+-  :ref:`Variables <lang-variables>`
+
+
+.. include:: cc-attribution.txt