Add 7 segment invert to its example, adjust to default to non-inverted mode.

Author: tdicola

Adafruit_LED_Backpack/SevenSegment.py

@@ -69,12 +69,12 @@
 class SevenSegment(HT16K33.HT16K33):
 	"""Seven segment LED backpack display."""
 
-	def __init__(self, **kwargs):
+	def __init__(self, invert=False, **kwargs):
 		"""Initialize display.  All arguments will be passed to the HT16K33 class
 		initializer, including optional I2C address and bus number parameters.
 		"""
 		super(SevenSegment, self).__init__(**kwargs)
-		self.invert = True
+		self.invert = invert
 
 	def set_invert(self, _invert):
 		"""Set whether the display is upside-down or not.

examples/sevensegment_test.py

@@ -72,7 +72,17 @@
 		display.print_hex(i)
 		display.set_colon(colon)
 		display.write_display()
-		time.sleep(0.5)
+		time.sleep(0.25)
+	# Run through hex digits with an inverted (flipped upside down)
+	# display.
+	display.set_invert(True)
+	for i in range(0xFF):
+		display.clear()
+		display.print_hex(i)
+		display.set_colon(colon)
+		display.write_display()
+		time.sleep(0.25)
+	display.set_invert(False)
 	# Flip colon on or off.
 	colon = not colon