Merge pull request #20 from kattni/touch-threshold

Added ability to change touch threshold

Author: dhalbert

_static/capacitive_touch_pads.jpg

@@ -66,7 +66,8 @@ def light(self):
         """Light level in SI Lux."""
         return self._photocell.value * 330 // (2 ** 16)
 
-class Express:
+
+class Express:     # pylint: disable=too-many-public-methods
     """Represents a single CircuitPlayground Express. Do not use more than one at
        a time."""
     def __init__(self):
@@ -110,6 +111,7 @@ def __init__(self):
         self._touch_A5 = None
         self._touch_A6 = None
         self._touch_A7 = None
+        self._touch_threshold_adjustment = 0
 
         # Define acceleration:
         self._i2c = busio.I2C(board.ACCELEROMETER_SCL, board.ACCELEROMETER_SDA)
@@ -188,6 +190,7 @@ def touch_A1(self): # pylint: disable=invalid-name
         """
         if self._touch_A1 is None:
             self._touch_A1 = touchio.TouchIn(board.A1)
+            self._touch_A1.threshold += self._touch_threshold_adjustment
         return self._touch_A1.value
 
     @property
@@ -207,6 +210,7 @@ def touch_A2(self): # pylint: disable=invalid-name
         """
         if self._touch_A2 is None:
             self._touch_A2 = touchio.TouchIn(board.A2)
+            self._touch_A2.threshold += self._touch_threshold_adjustment
         return self._touch_A2.value
 
     @property
@@ -226,6 +230,7 @@ def touch_A3(self): # pylint: disable=invalid-name
         """
         if self._touch_A3 is None:
             self._touch_A3 = touchio.TouchIn(board.A3)
+            self._touch_A3.threshold += self._touch_threshold_adjustment
         return self._touch_A3.value
 
     @property
@@ -245,6 +250,7 @@ def touch_A4(self): # pylint: disable=invalid-name
         """
         if self._touch_A4 is None:
             self._touch_A4 = touchio.TouchIn(board.A4)
+            self._touch_A4.threshold += self._touch_threshold_adjustment
         return self._touch_A4.value
 
     @property
@@ -264,6 +270,7 @@ def touch_A5(self): # pylint: disable=invalid-name
         """
         if self._touch_A5 is None:
             self._touch_A5 = touchio.TouchIn(board.A5)
+            self._touch_A5.threshold += self._touch_threshold_adjustment
         return self._touch_A5.value
 
     @property
@@ -283,6 +290,7 @@ def touch_A6(self): # pylint: disable=invalid-name
         """
         if self._touch_A6 is None:
             self._touch_A6 = touchio.TouchIn(board.A6)
+            self._touch_A6.threshold += self._touch_threshold_adjustment
         return self._touch_A6.value
 
     @property
@@ -302,8 +310,34 @@ def touch_A7(self): # pylint: disable=invalid-name
         """
         if self._touch_A7 is None:
             self._touch_A7 = touchio.TouchIn(board.A7)
+            self._touch_A7.threshold += self._touch_threshold_adjustment
         return self._touch_A7.value
 
+    def adjust_touch_threshold(self, adjustment):
+        """Adjust the threshold needed to activate the capacitive touch pads.
+        Higher numbers make the touch pads less sensitive.
+
+        :param int adjustment: The desired threshold increase
+
+        .. image :: /_static/capacitive_touch_pads.jpg
+          :alt: Capacitive touch pads
+
+        .. code-block:: python
+
+          from adafruit_circuitplayground.express import cpx
+
+          cpx.adjust_touch_threshold(200)
+
+          while True:
+              if cpx.touch_A1:
+                  print('Touched pad A1')
+        """
+        for pad_name in ["_touch_A" + str(x) for x in range(1, 8)]:
+            touch_in = getattr(self, pad_name)
+            if touch_in:
+                touch_in.threshold += adjustment
+        self._touch_threshold_adjustment += adjustment
+
     @property
     def pixels(self):
         """Sequence like object representing the ten NeoPixels around the outside