Acceleration implemented. (#11)

Sphinx docs added, conf.py updated, image included.

Author: kattni

_static/accelerometer.jpg

@@ -1,8 +1,10 @@
+import adafruit_lis3dh
 import adafruit_thermistor
 import analogio
 import array
 import audioio
 import board
+import busio
 import digitalio
 import math
 import neopixel
@@ -60,6 +62,32 @@ def __init__(self):
         self._touch_A6 = None
         self._touch_A7 = None
 
+        # Define acceleration:
+        self._i2c = busio.I2C(board.ACCELEROMETER_SCL, board.ACCELEROMETER_SDA)
+        self._lis3dh = adafruit_lis3dh.LIS3DH_I2C(self._i2c, address=0x19)
+        self._lis3dh.range = adafruit_lis3dh.RANGE_8_G
+        self._lis3dh._write_register_byte(adafruit_lis3dh.REG_CTRL5, 0b01001000)
+        self._lis3dh._write_register_byte(0x2E, 0b10000000)
+
+    @property
+    def acceleration(self):
+        """Obtain data from the x, y and z axes.
+
+        .. image :: /_static/accelerometer.jpg
+
+        This example prints the values. Try moving the board to see how the
+        printed values change.
+
+        .. code-block:: python
+
+          from adafruit_circuitplayground.express import cpx
+
+          while True:
+              x, y, z = cpx.acceleration
+              print(x, y, z)
+        """
+        return self._lis3dh.acceleration
+
     @property
     def touch_A1(self):
         """Detect touch on capacitive touch pad A1.

adafruit_circuitplayground/express.py

@@ -20,7 +20,7 @@
                        'NeoPixel': ('https://circuitpython.readthedocs.io/projects/neopixel/en/latest/', None)}
 
 # Libraries we depend on but don't need for generating docs.
-autodoc_mock_imports = ["board", "analogio", "digitalio", "neopixel", "adafruit_thermistor", "audioio", "touchio"]
+autodoc_mock_imports = ["board", "analogio", "digitalio", "neopixel", "adafruit_thermistor", "audioio", "touchio", "adafruit_lis3dh", "busio"]
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']