text: #!/usr/bin/env python
  #
  # GrovePi Example for using the Grove - LCD RGB Backlight (http://www.seeedstudio.com/wiki/Grove_-_LCD_RGB_Backlight)
  #
  # The GrovePi connects the Raspberry Pi and Grove sensors.  You can learn more about GrovePi here:  http://www.dexterindustries.com/GrovePi
  #
  # Have a question about this example?  Ask on the forums here:  http://forum.dexterindustries.com/c/grovepi
  #
  # History
  # ------------------------------------------------
  # Author	Date      		Comments
  # 						  	Initial Authoring
  # Karan		7 Jan 16		Library updated to add a function to update the text without erasing the screen
  '''
  ## License
  
  The MIT License (MIT)
  
  GrovePi for the Raspberry Pi: an open source platform for connecting Grove Sensors to the Raspberry Pi.
  Copyright (C) 2017  Dexter Industries
  
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
  
  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.
  
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  THE SOFTWARE.
  '''
  #
  # NOTE:
  # 	Just supports setting the backlight colour, and
  # 	putting a single string of text onto the display
  # 	Doesn't support anything clever, cursors or anything
  
  import time,sys
  
  if sys.platform == 'uwp':
      import winrt_smbus as smbus
      bus = smbus.SMBus(1)
  else:
      import smbus
      import RPi.GPIO as GPIO
      rev = GPIO.RPI_REVISION
      if rev == 2 or rev == 3:
          bus = smbus.SMBus(1)
      else:
          bus = smbus.SMBus(0)
  
  # this device has two I2C addresses
  DISPLAY_RGB_ADDR = 0x62
  DISPLAY_TEXT_ADDR = 0x3e
  
  # set backlight to (R,G,B) (values from 0..255 for each)
  def setRGB(r,g,b):
      bus.write_byte_data(DISPLAY_RGB_ADDR,0,0)
      bus.write_byte_data(DISPLAY_RGB_ADDR,1,0)
      bus.write_byte_data(DISPLAY_RGB_ADDR,0x08,0xaa)
      bus.write_byte_data(DISPLAY_RGB_ADDR,4,r)
      bus.write_byte_data(DISPLAY_RGB_ADDR,3,g)
      bus.write_byte_data(DISPLAY_RGB_ADDR,2,b)
  
  # send command to display (no need for external use)    
  def textCommand(cmd):
      bus.write_byte_data(DISPLAY_TEXT_ADDR,0x80,cmd)
  
  # set display text \n for second line(or auto wrap)     
  def setText(text):
      textCommand(0x01) # clear display
      time.sleep(.05)
      textCommand(0x08 | 0x04) # display on, no cursor
      textCommand(0x28) # 2 lines
      time.sleep(.05)
      count = 0
      row = 0
      for c in text:
          if c == '\n' or count == 16:
              count = 0
              row += 1
              if row == 2:
                  break
              textCommand(0xc0)
              if c == '\n':
                  continue
          count += 1
          bus.write_byte_data(DISPLAY_TEXT_ADDR,0x40,ord(c))
  
  #Update the display without erasing the display
  def setText_norefresh(text):
      textCommand(0x02) # return home
      time.sleep(.05)
      textCommand(0x08 | 0x04) # display on, no cursor
      textCommand(0x28) # 2 lines
      time.sleep(.05)
      count = 0
      row = 0
      while len(text) < 32: #clears the rest of the screen
          text += ' '
      for c in text:
          if c == '\n' or count == 16:
              count = 0
              row += 1
              if row == 2:
                  break
              textCommand(0xc0)
              if c == '\n':
                  continue
          count += 1
          bus.write_byte_data(DISPLAY_TEXT_ADDR,0x40,ord(c))
  
  # Create a custom character (from array of row patterns)
  def create_char(location, pattern):
      location &= 0x07 # Make sure location is 0-7
      textCommand(0x40 | (location << 3))
      bus.write_i2c_block_data(DISPLAY_TEXT_ADDR, 0x40, pattern)
  
  # example code
  if __name__=="__main__":
      setText("Hello world\nThis is an LCD test")
      setRGB(0,128,64)
      time.sleep(2)
      for c in range(0,255):
          setText_norefresh("Going to sleep in {}...".format(str(c)))
          setRGB(c,255-c,0)
          time.sleep(0.1)
      setRGB(0,255,0)
      setText("Bye bye, this should wrap onto next line")
  
      
  