Create Adafruit_QuadAlphanum.py

Adafruit_LEDBackpack/Adafruit_QuadAlphanum.py

@@ -0,0 +1,277 @@
+#!/usr/bin/python
+
+import time
+from Adafruit_LEDBackpack import LEDBackpack
+
+# ===========================================================================
+# Quad Alphabumeric Display
+# Handles a display consisting of one or more 4-digit segments.
+#
+# Products:
+# http://www.adafruit.com/products/1911
+# http://www.adafruit.com/products/1912
+# ===========================================================================
+
+class QuadAlphanum:
+  disp = []
+  maxDigit = 0
+  debug = False
+
+  # The pixel matrix has been copied from the Adafruit Arduino library.
+  alphafonttable = [
+	  0b0000000000000001,
+	  0b0000000000000010,
+	  0b0000000000000100,
+	  0b0000000000001000,
+	  0b0000000000010000,
+	  0b0000000000100000,
+	  0b0000000001000000,
+	  0b0000000010000000,
+	  0b0000000100000000,
+	  0b0000001000000000,
+	  0b0000010000000000,
+	  0b0000100000000000,
+	  0b0001000000000000,
+	  0b0010000000000000,
+	  0b0100000000000000,
+	  0b1000000000000000,
+	  0b0000000000000000,
+	  0b0000000000000000,
+	  0b0000000000000000,
+	  0b0000000000000000,
+	  0b0000000000000000,
+	  0b0000000000000000,
+	  0b0000000000000000,
+	  0b0000000000000000,
+	  0b0001001011001001,
+	  0b0001010111000000,
+	  0b0001001011111001,
+	  0b0000000011100011,
+	  0b0000010100110000,
+	  0b0001001011001000,
+	  0b0011101000000000,
+	  0b0001011100000000,
+	  0b0000000000000000, #  
+	  0b0000000000000110, # !
+	  0b0000001000100000, # "
+	  0b0001001011001110, # #
+	  0b0001001011101101, # $
+	  0b0000110000100100, # %
+	  0b0010001101011101, # &
+	  0b0000010000000000, # '
+	  0b0010010000000000, # (
+	  0b0000100100000000, # )
+	  0b0011111111000000, # *
+	  0b0001001011000000, # +
+	  0b0000100000000000, # ,
+	  0b0000000011000000, # -
+	  0b0100000000000000, # .
+	  0b0000110000000000, # /
+	  0b0000110000111111, # 0
+	  0b0000000000000110, # 1
+	  0b0000000011011011, # 2
+	  0b0000000010001111, # 3
+	  0b0000000011100110, # 4
+	  0b0010000001101001, # 5
+	  0b0000000011111101, # 6
+	  0b0000000000000111, # 7
+	  0b0000000011111111, # 8
+	  0b0000000011101111, # 9
+	  0b0001001000000000, # :
+	  0b0000101000000000, # ;
+	  0b0010010000000000, # <
+	  0b0000000011001000, # =
+	  0b0000100100000000, # >
+	  0b0001000010000011, # ?
+	  0b0000001010111011, # @
+	  0b0000000011110111, # A
+	  0b0001001010001111, # B
+	  0b0000000000111001, # C
+	  0b0001001000001111, # D
+	  0b0000000011111001, # E
+	  0b0000000001110001, # F
+	  0b0000000010111101, # G
+	  0b0000000011110110, # H
+	  0b0001001000000000, # I
+	  0b0000000000011110, # J
+	  0b0010010001110000, # K
+	  0b0000000000111000, # L
+	  0b0000010100110110, # M
+	  0b0010000100110110, # N
+	  0b0000000000111111, # O
+	  0b0000000011110011, # P
+	  0b0010000000111111, # Q
+	  0b0010000011110011, # R
+	  0b0000000011101101, # S
+	  0b0001001000000001, # T
+	  0b0000000000111110, # U
+	  0b0000110000110000, # V
+	  0b0010100000110110, # W
+	  0b0010110100000000, # X
+	  0b0001010100000000, # Y
+	  0b0000110000001001, # Z
+	  0b0000000000111001, # [
+	  0b0010000100000000, # 
+	  0b0000000000001111, # ]
+	  0b0000110000000011, # ^
+	  0b0000000000001000, # _
+	  0b0000000100000000, # `
+	  0b0001000001011000, # a
+	  0b0010000001111000, # b
+	  0b0000000011011000, # c
+	  0b0000100010001110, # d
+	  0b0000100001011000, # e
+	  0b0000000001110001, # f
+	  0b0000010010001110, # g
+	  0b0001000001110000, # h
+	  0b0001000000000000, # i
+	  0b0000000000001110, # j
+	  0b0011011000000000, # k
+	  0b0000000000110000, # l
+	  0b0001000011010100, # m
+	  0b0001000001010000, # n
+	  0b0000000011011100, # o
+	  0b0000000101110000, # p
+	  0b0000010010000110, # q
+	  0b0000000001010000, # r
+	  0b0010000010001000, # s
+	  0b0000000001111000, # t
+	  0b0000000000011100, # u
+	  0b0010000000000100, # v
+	  0b0010100000010100, # w
+	  0b0010100011000000, # x
+	  0b0010000000001100, # y
+	  0b0000100001001000, # z
+	  0b0000100101001001, # {
+	  0b0001001000000000, # |
+	  0b0010010010001001, # }
+	  0b0000010100100000, # ~
+	  0b0011111111111111
+  ]
+
+  # Constructor
+  def __init__(self, address=0x70, segments=1, debug=False):
+    "Construct a display consisting of one or more 4-digit segments."
+    # Save the upper limit for convenience
+    self.maxDigit = 4 * segments
+    self.debug = debug
+    for segment in range(segments):
+      addr = address + segment
+      if (debug):
+        print "Initializing a new instance of LEDBackpack at 0x%02X" % addr
+      self.disp.append( LEDBackpack(address=addr, debug=debug) )
+
+  def writeDigitRaw(self, value, pos, update=True):
+    "Sets a digit using a raw 16-bit value"
+    if (pos < 0 or pos >= self.maxDigit):
+      # The position is out of range: To be expected by "setMessage()"
+      return
+    # Set the appropriate character
+    self.disp[pos/4].setBufferRow(pos%4, value, update)
+
+  def writeDigitAscii(self, char, pos, dot=False, update=True):
+    "Lookup pixels from ascii table."
+    if ord(char) < 0 or ord(char) > 127:
+      if (self.debug):
+        print "Invalid character: " + ord(char)
+      return
+    # Lookup and convert to font
+    font = self.alphafonttable[ord(char)]
+    if (dot):
+      font |= (1<<14)
+    self.writeDigitRaw(font, pos, update)
+
+  def setMessage(self, text, pos=0):
+    "Write a message on the display. No scroll. Return next free position."
+    for char in text:
+      if char == '.' and pos > 0 and pos <= self.maxDigit:
+        # Dot: Update previous digit with a dot instead of writing a new letter.
+        buffer = self.disp[(pos-1)/4].getBuffer()
+        # Retrieved data has "font" format, not ASCII
+        font = buffer[(pos-1)%4]
+        # Set the dot
+        font |= (1<<14)
+        # Rewrite the last letter as a modified "font"
+        self.writeDigitRaw(font, pos-1, False)
+      else:
+        # Normal case
+        self.writeDigitAscii(char, pos, False, False)
+        pos += 1
+    self.writeDisplay()
+    return pos
+
+  def scrollMessage(self, text, scrollSpeed=0.3):
+    "Scroll a message across the display."
+    for char in text:
+      if char == '.':
+        # Dot: Update last digit with dot instead of writing new letter.
+        buffer = self.disp[(self.maxDigit-1)/4].getBuffer()
+        # Retrieved data has "font" format, not ASCII
+        font = buffer[(self.maxDigit-1)%4]
+        # Set the dot
+        font |= (1<<14)
+        # Rewrite the last letter as a modified "font"
+        self.writeDigitRaw(font, self.maxDigit-1, True)
+        # Do not sleep to ensure a semmingly fixed scroll speed
+      else:
+        # Normal case
+        self.scrollLetter(char)
+        time.sleep(scrollSpeed)
+
+  def scrollLetter(self, char, dot=False):
+    "Scroll the display and write the last letter"
+    # Scroll all characters without updating the segments
+    self.shiftLeft()
+    # Write last character without updating the last segment
+    self.writeDigitAscii(char, self.maxDigit-1, dot, update=False)
+    # Update all segments
+    self.writeDisplay()
+
+  def shiftLeft(self):
+    buffer = self.disp[0].getBuffer()
+    for segment in range(0, len(self.disp)):
+      for x in range (0, 3):
+        # Shift 3 first columns of segment, no update during shift
+        self.disp[segment].setBufferRow(x, buffer[x+1], False)
+      if (segment + 1 < len(self.disp)):
+        # Unless this is th last digit:
+        # Transfer first column of next segment and update
+        next_buffer = self.disp[segment+1].getBuffer()
+        self.disp[segment].setBufferRow(3, next_buffer[0], False)
+        buffer = next_buffer
+
+  def writeDisplay(self):
+    """Explicitely update the display.
+    Used if you have written to the buffer with no update.
+    """
+    for segment in self.disp:
+      segment.writeDisplay()
+
+  def clear(self):
+    "Clears the entire display"
+    for segment in self.disp:
+      segment.clear()
+
+  def setBrightness(self, brightness):
+    "Set brightness for all displays"
+    for segment in self.disp:
+      segment.setBrightness(brightness)
+
+  # No use to handle multiple blinking segments:
+  # They will never blink in sync anyway.
+
+if __name__ == '__main__':
+  "Self test / demo."
+  screen = QuadAlphanum(0x70, 1, True)
+  screen.setMessage("TEST.")
+  time.sleep(2)
+  screen.clear()
+  screen.setMessage("fixed", 1)
+  time.sleep(2)
+  screen.scrollMessage(" and scrolling text.")
+  for brightness in range (15, 0, -1):
+    time.sleep(0.25)
+    screen.setBrightness(brightness)
+  screen.clear()
+  screen.setMessage("Done.")
+  screen.setBrightness(15)