lcdks: renamed from sainsmartks, added backlight support

The sainsmartks driver has been reimplemented in it's own, new C/C++
library: lcdks (LCD Keypad Shield).

In addition, support for an optional backlight GPIO was added.

This was tested with the SainsmartKS and DFRobot LCD Keypad Shields.

Signed-off-by: Jon Trulson <jtrulson@ics.com>

examples/python/lcdks.py

@@ -1,6 +1,8 @@
 #!/usr/bin/python
 # Author: Jon Trulson <jtrulson@ics.com>
-# Copyright (c) 2015 Intel Corporation.
+# Copyright (c) 2017 Intel Corporation.
+#
+# The MIT License
 #
 # Permission is hereby granted, free of charge, to any person obtaining
 # a copy of this software and associated documentation files (the
@@ -23,7 +25,7 @@
 
 from __future__ import print_function
 import time, sys, signal, atexit
-from upm import pyupm_i2clcd as sainsmartObj
+from upm import pyupm_lcdks as lcdksObj
 
 def main():
     ## Exit handlers ##
@@ -32,7 +34,6 @@ def main():
         raise SystemExit
 
     # This function lets you run code on exit,
-    # including functions from ringCoder
     def exitHandler():
         print("Exiting")
         sys.exit(0)
@@ -41,17 +42,21 @@ def main():
     atexit.register(exitHandler)
     signal.signal(signal.SIGINT, SIGINTHandler)
 
-    # Instantiate a Sainsmart LCD Keypad Shield using default pins
-    lcd = sainsmartObj.SAINSMARTKS()
+    # Instantiate a LCDKS (LCD Keypad Shield) using default pins
+
+    # NOTE: The default pins do not include support for a gpio
+    # controlled backlight.  If you need one, you will need to specify
+    # all neccessary pins to the constructor.
+    lcd = lcdksObj.LCDKS()
 
     lcd.setCursor(0,0)
-    lcd.write("Sainsmart KS")
+    lcd.write("LCDKS driver")
     lcd.setCursor(1,2)
     lcd.write("Hello World")
 
     # output current key value every second.
     while(1):
-        print("Button value: ", lcd.getRawKeyValue())
+        print("Button value: ", lcd.getKeyValue())
         time.sleep(1)
 
 if __name__ == '__main__':