Added some test for the LCD and fixed paths to programs to be absolute.

1 files changed, 178 insertions, 0 deletions

diff --git a/I2C_LCD_driver.py b/I2C_LCD_driver.py
new file mode 100644
index 0000000..0a58e30
--- /dev/null
+++ b/I2C_LCD_driver.py
@@ -0,0 +1,178 @@
+# -*- coding: utf-8 -*-
+# Original code found at:
+# https://gist.github.com/DenisFromHR/cc863375a6e19dce359d
+
+"""
+Compiled, mashed and generally mutilated 2014-2015 by Denis Pleic
+Made available under GNU GENERAL PUBLIC LICENSE
+
+# Modified Python I2C library for Raspberry Pi
+# as found on http://www.recantha.co.uk/blog/?p=4849
+# Joined existing 'i2c_lib.py' and 'lcddriver.py' into a single library
+# added bits and pieces from various sources
+# By DenisFromHR (Denis Pleic)
+# 2015-02-10, ver 0.1
+
+"""
+
+# i2c bus (0 -- original Pi, 1 -- Rev 2 Pi)
+I2CBUS = 0
+
+# LCD Address
+ADDRESS = 0x27
+
+import smbus
+from time import sleep
+
+class i2c_device:
+   def __init__(self, addr, port=I2CBUS):
+      self.addr = addr
+      self.bus = smbus.SMBus(port)
+
+# Write a single command
+   def write_cmd(self, cmd):
+      self.bus.write_byte(self.addr, cmd)
+      sleep(0.0001)
+
+# Write a command and argument
+   def write_cmd_arg(self, cmd, data):
+      self.bus.write_byte_data(self.addr, cmd, data)
+      sleep(0.0001)
+
+# Write a block of data
+   def write_block_data(self, cmd, data):
+      self.bus.write_block_data(self.addr, cmd, data)
+      sleep(0.0001)
+
+# Read a single byte
+   def read(self):
+      return self.bus.read_byte(self.addr)
+
+# Read
+   def read_data(self, cmd):
+      return self.bus.read_byte_data(self.addr, cmd)
+
+# Read a block of data
+   def read_block_data(self, cmd):
+      return self.bus.read_block_data(self.addr, cmd)
+
+
+# commands
+LCD_CLEARDISPLAY = 0x01
+LCD_RETURNHOME = 0x02
+LCD_ENTRYMODESET = 0x04
+LCD_DISPLAYCONTROL = 0x08
+LCD_CURSORSHIFT = 0x10
+LCD_FUNCTIONSET = 0x20
+LCD_SETCGRAMADDR = 0x40
+LCD_SETDDRAMADDR = 0x80
+
+# flags for display entry mode
+LCD_ENTRYRIGHT = 0x00
+LCD_ENTRYLEFT = 0x02
+LCD_ENTRYSHIFTINCREMENT = 0x01
+LCD_ENTRYSHIFTDECREMENT = 0x00
+
+# flags for display on/off control
+LCD_DISPLAYON = 0x04
+LCD_DISPLAYOFF = 0x00
+LCD_CURSORON = 0x02
+LCD_CURSOROFF = 0x00
+LCD_BLINKON = 0x01
+LCD_BLINKOFF = 0x00
+
+# flags for display/cursor shift
+LCD_DISPLAYMOVE = 0x08
+LCD_CURSORMOVE = 0x00
+LCD_MOVERIGHT = 0x04
+LCD_MOVELEFT = 0x00
+
+# flags for function set
+LCD_8BITMODE = 0x10
+LCD_4BITMODE = 0x00
+LCD_2LINE = 0x08
+LCD_1LINE = 0x00
+LCD_5x10DOTS = 0x04
+LCD_5x8DOTS = 0x00
+
+# flags for backlight control
+LCD_BACKLIGHT = 0x08
+LCD_NOBACKLIGHT = 0x00
+
+En = 0b00000100 # Enable bit
+Rw = 0b00000010 # Read/Write bit
+Rs = 0b00000001 # Register select bit
+
+class lcd:
+   #initializes objects and lcd
+   def __init__(self):
+      self.lcd_device = i2c_device(ADDRESS)
+
+      self.lcd_write(0x03)
+      self.lcd_write(0x03)
+      self.lcd_write(0x03)
+      self.lcd_write(0x02)
+
+      self.lcd_write(LCD_FUNCTIONSET | LCD_2LINE | LCD_5x8DOTS | LCD_4BITMODE)
+      self.lcd_write(LCD_DISPLAYCONTROL | LCD_DISPLAYON)
+      self.lcd_write(LCD_CLEARDISPLAY)
+      self.lcd_write(LCD_ENTRYMODESET | LCD_ENTRYLEFT)
+      sleep(0.2)
+
+
+   # clocks EN to latch command
+   def lcd_strobe(self, data):
+      self.lcd_device.write_cmd(data | En | LCD_BACKLIGHT)
+      sleep(.0005)
+      self.lcd_device.write_cmd(((data & ~En) | LCD_BACKLIGHT))
+      sleep(.0001)
+
+   def lcd_write_four_bits(self, data):
+      self.lcd_device.write_cmd(data | LCD_BACKLIGHT)
+      self.lcd_strobe(data)
+
+   # write a command to lcd
+   def lcd_write(self, cmd, mode=0):
+      self.lcd_write_four_bits(mode | (cmd & 0xF0))
+      self.lcd_write_four_bits(mode | ((cmd << 4) & 0xF0))
+
+   # write a character to lcd (or character rom) 0x09: backlight | RS=DR<
+   # works!
+   def lcd_write_char(self, charvalue, mode=1):
+      self.lcd_write_four_bits(mode | (charvalue & 0xF0))
+      self.lcd_write_four_bits(mode | ((charvalue << 4) & 0xF0))
+  
+   # put string function with optional char positioning
+   def lcd_display_string(self, string, line=1, pos=0):
+    if line == 1:
+      pos_new = pos
+    elif line == 2:
+      pos_new = 0x40 + pos
+    elif line == 3:
+      pos_new = 0x14 + pos
+    elif line == 4:
+      pos_new = 0x54 + pos
+
+    self.lcd_write(0x80 + pos_new)
+
+    for char in string:
+      self.lcd_write(ord(char), Rs)
+
+   # clear lcd and set to home
+   def lcd_clear(self):
+      self.lcd_write(LCD_CLEARDISPLAY)
+      self.lcd_write(LCD_RETURNHOME)
+
+   # define backlight on/off (lcd.backlight(1); off= lcd.backlight(0)
+   def backlight(self, state): # for state, 1 = on, 0 = off
+      if state == 1:
+         self.lcd_device.write_cmd(LCD_BACKLIGHT)
+      elif state == 0:
+         self.lcd_device.write_cmd(LCD_NOBACKLIGHT)
+
+   # add custom characters (0 - 7)
+   def lcd_load_custom_chars(self, fontdata):
+      self.lcd_write(0x40);
+      for char in fontdata:
+         for line in char:
+            self.lcd_write_char(line)