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Software/Python/grove_rgb_lcd/grove_rgb_lcd.py

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+#!/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
+# Released under the MIT license (http://choosealicense.com/licenses/mit/).
+# For more information see https://github.com/DexterInd/GrovePi/blob/master/LICENSE
+
+#
+# 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):
+    """
+    Writes a bit pattern to LCD CGRAM
+
+    Arguments:
+    location -- integer, one of 8 slots (0-7)
+    pattern -- byte array containing the bit pattern, like as found at
+               https://omerk.github.io/lcdchargen/
+    """
+    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")