Initial merge of micropython v1.9.2 into circuitpython 2.0.0 (in development) master.

cpx build compiles and loads and works in repl; test suite not run yet
esp8266 not tested yet

3 files changed, 36 insertions, 4 deletions

diff --git a/docs/pyboard/tutorial/amp_skin.rst b/docs/pyboard/tutorial/amp_skin.rst
index 64f139bb7..697637f9d 100644
--- a/docs/pyboard/tutorial/amp_skin.rst
+++ b/docs/pyboard/tutorial/amp_skin.rst
@@ -69,4 +69,30 @@ Then you can do::
     >>> f = wave.open('test.wav')
     >>> dac.write_timed(f.readframes(f.getnframes()), f.getframerate())
 
-This should play the WAV file.
+This should play the WAV file. Note that this will read the whole file into RAM
+so it has to be small enough to fit in it.
+
+To play larger wave files you will have to use the micro-SD card to store it.
+Also the file must be read and sent to the DAC in small chunks that will fit
+the RAM limit of the microcontroller.  Here is an example function that can
+play 8-bit wave files with up to 16kHz sampling::
+
+    import wave
+    from pyb import DAC
+    from pyb import delay
+    dac = DAC(1)
+
+    def play(filename):
+        f = wave.open(filename, 'r')
+        total_frames = f.getnframes()
+        framerate = f.getframerate()
+
+        for position in range(0, total_frames, framerate):
+            f.setpos(position)
+            dac.write_timed(f.readframes(framerate), framerate)
+            delay(1000)
+
+This function reads one second worth of data and sends it to DAC.  It then waits
+one second and moves the file cursor to the new position to read the next second
+of data in the next iteration of the for-loop.  It plays one second of audio at
+a time every one second.
diff --git a/docs/pyboard/tutorial/index.rst b/docs/pyboard/tutorial/index.rst
index 07f136c9b..1dc155f14 100644
--- a/docs/pyboard/tutorial/index.rst
+++ b/docs/pyboard/tutorial/index.rst
@@ -1,7 +1,7 @@
 .. _tutorial-index:
 
-MicroPython tutorial
-====================
+MicroPython tutorial for the pyboard
+====================================
 
 This tutorial is intended to get you started with your pyboard.
 All you need is a pyboard and a micro-USB cable to connect it to
diff --git a/docs/pyboard/tutorial/switch.rst b/docs/pyboard/tutorial/switch.rst
index 945e89aa0..91683fba4 100644
--- a/docs/pyboard/tutorial/switch.rst
+++ b/docs/pyboard/tutorial/switch.rst
@@ -15,12 +15,18 @@ the name ``pyb`` does not exist.
 
 With the switch object you can get its status::
 
-    >>> sw()
+    >>> sw.value()
     False
 
 This will print ``False`` if the switch is not held, or ``True`` if it is held.
 Try holding the USR switch down while running the above command.
 
+There is also a shorthand notation to get the switch status, by "calling" the
+switch object::
+
+    >>> sw()
+    False
+
 Switch callbacks
 ----------------