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Commit 24fd2f4

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tdicolatdicola
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Resolve #43 and resolve #44 by adding 20x4 LCD support and 20x4 example.
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2 files changed

+180
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‎Adafruit_CharLCDPlate/Adafruit_CharLCDPlate.py

+24-4
Original file line numberDiff line numberDiff line change
@@ -11,6 +11,7 @@
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from Adafruit_I2C import Adafruit_I2C
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from time import sleep
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class Adafruit_CharLCDPlate(Adafruit_I2C):
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# ----------------------------------------------------------------------
@@ -72,6 +73,13 @@ class Adafruit_CharLCDPlate(Adafruit_I2C):
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LCD_MOVERIGHT = 0x04
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LCD_MOVELEFT = 0x00
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# Line addresses for up to 4 line displays. Maps line number to DDRAM address for line.
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LINE_ADDRESSES = { 1: 0xC0, 2: 0x94, 3: 0xD4 }
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# Truncation constants for message function truncate parameter.
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NO_TRUNCATE = 0
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TRUNCATE = 1
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TRUNCATE_ELLIPSIS = 2
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# ----------------------------------------------------------------------
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# Constructor
@@ -265,6 +273,7 @@ def write(self, value, char_mode=False):
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def begin(self, cols, lines):
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self.currline = 0
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self.numlines = lines
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self.numcols = cols
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self.clear()
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@@ -409,13 +418,24 @@ def createChar(self, location, bitmap):
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self.write(self.LCD_SETDDRAMADDR)
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def message(self, text):
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def message(self, text, truncate=NO_TRUNCATE):
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""" Send string to LCD. Newline wraps to second line"""
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lines = str(text).split('\n') # Split at newline(s)
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for i, line in enumerate(lines): # For each substring...
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if i > 0: # If newline(s),
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self.write(0xC0) # set DDRAM address to 2nd line
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self.write(line, True) # Issue substring
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address = self.LINE_ADDRESSES.get(i, None)
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if address is not None: # If newline(s),
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self.write(address) # set DDRAM address to line
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# Handle appropriate truncation if requested.
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linelen = len(line)
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if truncate == self.TRUNCATE and linelen > self.numcols:
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# Hard truncation of line.
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self.write(line[0:self.numcols], True)
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elif truncate == self.TRUNCATE_ELLIPSIS and linelen > self.numcols:
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# Nicer truncation with ellipses.
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self.write(line[0:self.numcols-3] + '...', True)
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else:
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self.write(line, True)
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def backlight(self, color):

‎Adafruit_CharLCDPlate/LCDtest_20x4.py

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,156 @@
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#!/usr/bin/python
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#----------------------------------------------------------------
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# Author: Chris Crumpacker
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# Date: May 2013
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#
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# A demo of some of the built in helper functions of
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# the Adafruit_CharLCDPlate.py This is 20x4 display specific.
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#
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# Using Adafruit_CharLCD code with the I2C and MCP230xx code aswell
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#----------------------------------------------------------------
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numcolumns = 20
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numrows = 4
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from time import sleep
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from Adafruit_CharLCDPlate import Adafruit_CharLCDPlate
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lcd = Adafruit_CharLCDPlate()
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lcd.begin(numcolumns, numrows)
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lcd.backlight(lcd.ON)
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lcd.message("LCD 20x4\nDemonstration")
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sleep(2)
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while True:
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#Text on each line alone.
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lcd.clear()
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lcd.setCursor(0,0)
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lcd.message("Line 1")
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sleep(1)
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lcd.clear()
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lcd.setCursor(0,1)
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lcd.message("Line 2")
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sleep(1)
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lcd.clear()
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lcd.setCursor(0,2)
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lcd.message("Line 3")
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sleep(1)
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lcd.clear()
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lcd.setCursor(0,3)
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lcd.message("Line 4")
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sleep(1)
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# Using the "\n" new line marker
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lcd.clear()
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lcd.setCursor(0,0)
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lcd.message("Line 1")
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sleep(1)
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lcd.clear()
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lcd.setCursor(0,0)
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lcd.message("Line 1\nLine 2")
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sleep(1)
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lcd.clear()
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lcd.setCursor(0,0)
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lcd.message("Line 1\nLine 2\nLine 3")
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sleep(1)
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lcd.clear()
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lcd.setCursor(0,0)
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lcd.message("Line 1\nLine 2\nLine 3\nLine 4")
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sleep(1)
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# Auto line limiting by length as to not overflow the display
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# This is line by line and does not to any caraige returns
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lcd.clear()
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lcd.setCursor(0,0)
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lcd.message("This String is 33 Characters long", lcd.TRUNCATE)
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sleep(2)
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lcd.clear()
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lcd.setCursor(0,0)
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lcd.message("This String has ellipsis", lcd.TRUNCATE_ELLIPSIS)
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sleep(2)
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#Scroll text to the right
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messageToPrint = "Scrolling Right"
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i=0
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while i<20:
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lcd.clear()
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lcd.setCursor(0,0)
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suffix = " " * i
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lcd.message(suffix + messageToPrint, lcd.TRUNCATE)
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sleep(.25)
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i += 1
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# Scroll test in from the Left
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messageToPrint = "Scrolling Left"
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i=20
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while i>=0:
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lcd.clear()
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lcd.setCursor(0,0)
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suffix = " " * i
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lcd.message(suffix + messageToPrint, lcd.TRUNCATE)
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sleep(.25)
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i -= 1
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sleep(2)
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# Printing text backwards, NOT right justified
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lcd.clear()
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lcd.setCursor(0,0)
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lcd.message("Right to left:")
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lcd.setCursor(10,1)
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lcd.rightToLeft()
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lcd.message("Testing")
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sleep(2)
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# Printing normally from the middle of the line
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lcd.clear()
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lcd.setCursor(0,0)
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lcd.message("Left to Right:")
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lcd.setCursor(10,1)
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lcd.message("Testing")
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sleep(2)
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# Enabling the cursor and having it blink
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lcd.clear()
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lcd.setCursor(0,0)
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lcd.cursor()
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lcd.blink()
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lcd.message("Cursor is blinking")
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lcd.setCursor(0,1)
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sleep(3)
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lcd.noCursor()
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lcd.noBlink()
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# Turning the backlight off and showing a simple count down
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lcd.clear()
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lcd.setCursor(0,0)
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lcd.message("Backlight off in")
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lcd.setCursor(0,3)
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lcd.message("Back on in 3sec")
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lcd.setCursor(17,0) #Reseting the cursor here keeps us from having to clear the screen, this over writes the previous character
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lcd.message("3")
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sleep(1)
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lcd.setCursor(17,0)
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lcd.message("2")
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sleep(1)
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lcd.setCursor(17,0)
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lcd.message("1")
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sleep(1)
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lcd.backlight(lcd.OFF)
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lcd.clear()
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lcd.setCursor(0,0)
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sleep(3)
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lcd.backlight(lcd.ON)
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lcd.message("Backlight on")

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