stdd/adafruit_7segment/Adafruit_7Segment.py

# -*- coding: utf-8-*-
#
# This file is part of stdd, the simple time display daemon,
# written by Helmut Pozimski <helmut@pozimski.eu>,
# licensed under the 3-clause BSD license
# This file was originally written by Written by Limor Fried, Kevin Townsend
# and Mikey Sklar for Adafruit Industries. BSD license,
# all text above must be included in any redistribution

import time
import datetime
from Adafruit_LEDBackpack import LEDBackpack

# ===========================================================================
# 7-Segment Display
# ===========================================================================

# This class is meant to be used with the four-character, seven segment
# displays available from Adafruit


class SevenSegment:
    disp = None

  # Hexadecimal character lookup table (row 1 = 0..9, row 2 = A..F)
    digits = [0x3F, 0x06, 0x5B, 0x4F, 0x66, 0x6D, 0x7D, 0x07, 0x7F, 0x6F,
              0x77, 0x7C, 0x39, 0x5E, 0x79, 0x71]

  # Constructor
    def __init__(self, address=0x70, debug=False):
        if (debug):
            print "Initializing a new instance of LEDBackpack at \
            0x%02X" % address
        self.disp = LEDBackpack(address=address, debug=debug)

    def writeDigitRaw(self, charNumber, value):
        "Sets a digit using the raw 16-bit value"
        if (charNumber > 7):
            return
        # Set the appropriate digit
        self.disp.setBufferRow(charNumber, value)

    def writeDigit(self, charNumber, value, dot=False):
        "Sets a single decimal or hexademical value (0..9 and A..F)"
        if (charNumber > 7):
            return
        if (value > 0xF):
            return
        # Set the appropriate digit
        self.disp.setBufferRow(charNumber, self.digits[value] | (dot << 7))

    def setColon(self, state=True):
        "Enables or disables the colon character"
        # 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)
        else:
            self.disp.setBufferRow(2, 0)

    def setBrightness(self, brightness):
        self.disp.setBrightness(brightness)