Documented setup of different colons as well as how the toggle works

Adafruit_LEDBackpack/Adafruit_7Segment.py

@@ -13,6 +13,18 @@
 
 class SevenSegment:
   disp = None
+
+  # Some 7Segment-Display have several different colons, e.g. the
+  # 1,2" display. To seperately control such different colons
+  # use the following values where applicable:
+  #
+  # 0x00 - nothing
+  # 0x02 - center colon
+  # 0x04 - left colon - upper dot
+  # 0x08 - left colon - lower dot
+  # 0x10 - decimal point
+  # 0xFFFF - everything (default)
+  mask_colons = 0xFFFF
 
   # Hexadecimal character lookup table (row 1 = 0..9, row 2 = A..F)
   digits = [ 0x3F, 0x06, 0x5B, 0x4F, 0x66, 0x6D, 0x7D, 0x07, 0x7F, 0x6F, \
@@ -45,8 +57,9 @@ def setColon(self, state=True):
     # Warning: This function assumes that the colon is character '2',
     # which is the case on 4 char displays, but may need to be modified
     # if another display type is used
+
     if (state):
-      self.disp.setBufferRow(2, 0xFFFF)
+      self.disp.setBufferRow(2, self.mask_colons)
     else:
       self.disp.setBufferRow(2, 0)
 

Adafruit_LEDBackpack/ex_7segment_clock.py

@@ -23,7 +23,12 @@
   # Set minutes
   segment.writeDigit(3, int(minute / 10))   # Tens
   segment.writeDigit(4, minute % 10)        # Ones
-  # Toggle colon
-  segment.setColon(second % 2)              # Toggle colon at 1Hz
-  # Wait one second
-  time.sleep(1)
+
+  # Toggle colon(s) as configured in Adafruit_7Segment.py
+  # every second (by using even seconds vs. odd seconds)
+  if (second % 2 == 0):                 # reminder = 0 -> even second
+    segment.setColon(0)                 # turn colons off
+  else:                                 # reminder != 0 -> odd second
+    segment.setColon(1)                 # turn colons on
+
+  time.sleep(1)                             # Wait one second