Enhanced adafruit LCD driver to support I2C in addition to GPIO

adafruit/Adafruit_CharLCD.py

@@ -0,0 +1,285 @@
+#!/usr/bin/python
+
+#
+# based on code from lrvick and LiquidCrystal
+# lrvic - https://github.com/lrvick/raspi-hd44780/blob/master/hd44780.py
+# LiquidCrystal - https://github.com/arduino/Arduino/blob/master/libraries/LiquidCrystal/LiquidCrystal.cpp
+#
+
+import time, smbus
+import subprocess, datetime
+
+class Adafruit_CharLCD_Virtual(object):
+    # 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
+
+    # 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
+
+
+    def __init__(self):
+
+        self.write4bits(0x33) # initialization
+        self.write4bits(0x32) # initialization
+        self.write4bits(0x28) # 2 line 5x7 matrix
+        self.write4bits(0x0C) # turn cursor off 0x0E to enable cursor
+        self.write4bits(0x06) # shift cursor right
+
+        self.displaycontrol = self.LCD_DISPLAYON | self.LCD_CURSOROFF | self.LCD_BLINKOFF
+
+        self.displayfunction = self.LCD_4BITMODE | self.LCD_1LINE | self.LCD_5x8DOTS
+        self.displayfunction |= self.LCD_2LINE
+
+        """ Initialize to default text direction (for romance languages) """
+        self.displaymode =  self.LCD_ENTRYLEFT | self.LCD_ENTRYSHIFTDECREMENT
+        self.write4bits(self.LCD_ENTRYMODESET | self.displaymode) #  set the entry mode
+
+        self.clear()
+
+    def begin(self, cols, lines):
+        if (lines > 1):
+            self.numlines = lines
+            self.displayfunction |= self.LCD_2LINE
+            self.currline = 0
+
+    def home(self):
+        self.write4bits(self.LCD_RETURNHOME) # set cursor position to zero
+        self.delayMicroseconds(3000) # this command takes a long time!
+
+    def clear(self):
+        self.write4bits(self.LCD_CLEARDISPLAY) # command to clear display
+        self.delayMicroseconds(3000)    # 3000 microsecond sleep, clearing the display takes a long time
+
+    def setCursor(self, col, row):
+        self.row_offsets = [ 0x00, 0x40, 0x14, 0x54 ]
+
+        if ( row > self.numlines ): 
+            row = self.numlines - 1 # we count rows starting w/0
+
+        self.write4bits(self.LCD_SETDDRAMADDR | (col + self.row_offsets[row]))
+
+    def noDisplay(self): 
+        """ Turn the display off (quickly) """
+        self.displaycontrol &= ~self.LCD_DISPLAYON
+        self.write4bits(self.LCD_DISPLAYCONTROL | self.displaycontrol)
+
+    def display(self):
+        """ Turn the display on (quickly) """
+        self.displaycontrol |= self.LCD_DISPLAYON
+        self.write4bits(self.LCD_DISPLAYCONTROL | self.displaycontrol)
+
+    def noCursor(self):
+        """ Turns the underline cursor on/off """
+        self.displaycontrol &= ~self.LCD_CURSORON
+        self.write4bits(self.LCD_DISPLAYCONTROL | self.displaycontrol)
+
+    def cursor(self):
+        """ Cursor On """
+        self.displaycontrol |= self.LCD_CURSORON
+        self.write4bits(self.LCD_DISPLAYCONTROL | self.displaycontrol)
+
+    def noBlink(self):
+        """ Turn on and off the blinking cursor """
+        self.displaycontrol &= ~self.LCD_BLINKON
+        self.write4bits(self.LCD_DISPLAYCONTROL | self.displaycontrol)
+
+    def DisplayLeft(self):
+        """ These commands scroll the display without changing the RAM """
+        self.write4bits(self.LCD_CURSORSHIFT | self.LCD_DISPLAYMOVE | self.LCD_MOVELEFT)
+
+    def scrollDisplayRight(self):
+        """ These commands scroll the display without changing the RAM """
+        self.write4bits(self.LCD_CURSORSHIFT | self.LCD_DISPLAYMOVE | self.LCD_MOVERIGHT);
+
+    def leftToRight(self):
+        """ This is for text that flows Left to Right """
+        self.displaymode |= self.LCD_ENTRYLEFT
+        self.write4bits(self.LCD_ENTRYMODESET | self.displaymode);
+
+    def rightToLeft(self):
+        """ This is for text that flows Right to Left """
+        self.displaymode &= ~self.LCD_ENTRYLEFT
+        self.write4bits(self.LCD_ENTRYMODESET | self.displaymode)
+
+    def autoscroll(self):
+        """ This will 'right justify' text from the cursor """
+        self.displaymode |= self.LCD_ENTRYSHIFTINCREMENT
+        self.write4bits(self.LCD_ENTRYMODESET | self.displaymode)
+
+    def noAutoscroll(self): 
+        """ This will 'left justify' text from the cursor """
+        self.displaymode &= ~self.LCD_ENTRYSHIFTINCREMENT
+        self.write4bits(self.LCD_ENTRYMODESET | self.displaymode)
+
+    def pulseEnable(self):
+        pass
+
+    def write4bits(self, bits, char_mode=False):
+        """ Send command to LCD """
+        pass
+
+    def delayMicroseconds(self, microseconds):
+        seconds = microseconds / float(1000000)    # divide microseconds by 1 million for seconds
+        time.sleep(seconds)
+
+    def message(self, text):
+        """ Send string to LCD. Newline wraps to second line"""
+        for char in text:
+            if char == '\n':
+                self.write4bits(0xC0) # next line
+            else:
+                self.write4bits(ord(char),True)
+
+
+
+class Adafruit_CharLCD_GPIO(Adafruit_CharLCD_Virtual):
+
+    def __init__(self, pin_rs=25, pin_e=24, pins_db=[23, 17, 27, 22], GPIO = None):
+        # Emulate the old behavior of using RPi.GPIO if we haven't been given
+        # an explicit GPIO interface to use
+        if not GPIO:
+            import RPi.GPIO as GPIO
+            self.GPIO = GPIO
+            self.pin_rs = pin_rs
+            self.pin_e = pin_e
+            self.pins_db = pins_db
+            self.GPIO.setmode(GPIO.BCM)
+            self.GPIO.setup(self.pin_e, GPIO.OUT)
+            self.GPIO.setup(self.pin_rs, GPIO.OUT)
+            for pin in self.pins_db:
+                self.GPIO.setup(pin, GPIO.OUT)
+
+        super(Adafruit_CharLCD_GPIO, self).__init__()
+
+    def pulseEnable(self):
+        self.GPIO.output(self.pin_e, False)
+        self.delayMicroseconds(1)       # 1 microsecond pause - enable pulse must be > 450ns 
+        self.GPIO.output(self.pin_e, True)
+        self.delayMicroseconds(1)       # 1 microsecond pause - enable pulse must be > 450ns 
+        self.GPIO.output(self.pin_e, False)
+        self.delayMicroseconds(1)       # commands need > 37us to settle
+
+    def write4bits(self, bits, char_mode=False):
+        """ Send command to LCD """
+        self.delayMicroseconds(1000) # 1000 microsecond sleep
+        bits=bin(bits)[2:].zfill(8)
+        self.GPIO.output(self.pin_rs, char_mode)
+        for pin in self.pins_db:
+            self.GPIO.output(pin, False)
+        for i in range(4):
+            if bits[i] == "1":
+                self.GPIO.output(self.pins_db[::-1][i], True)
+        self.pulseEnable()
+        for pin in self.pins_db:
+            self.GPIO.output(pin, False)
+        for i in range(4,8):
+            if bits[i] == "1":
+                self.GPIO.output(self.pins_db[::-1][i-4], True)
+        self.pulseEnable()
+
+
+# General i2c device class so that other devices can be added easily
+class i2c_device:
+    def __init__(self, addr, port):
+        self.addr = addr
+        self.bus = smbus.SMBus(port)
+
+    def write(self, byte):
+        self.bus.write_byte(self.addr, byte)
+
+    def read(self):
+        return self.bus.read_byte(self.addr)
+
+    def read_nbytes_data(self, data, n): # For sequential reads > 1 byte
+        return self.bus.read_i2c_block_data(self.addr, data, n)
+
+
+class Adafruit_CharLCD_I2C(Adafruit_CharLCD_Virtual):
+
+    def __init__(self, bus=1, device=0x20, bit_rs=4, bit_e=6):
+        self.i2c = i2c_device(device, bus)
+
+        # bit numbers on the I2C port expander
+        self.bit_rs = 1 << bit_rs
+        self.bit_e = 1 << bit_e
+
+        super(Adafruit_CharLCD_I2C, self).__init__()
+
+    def pulseEnable(self):
+        self.i2c.write((self.i2c.read() & (~self.bit_e & 0xFF)))
+        self.delayMicroseconds(1)        # 1 microsecond pause - enable pulse must be > 450ns 
+        self.i2c.write((self.i2c.read() | self.bit_e))
+        self.delayMicroseconds(1)        # 1 microsecond pause - enable pulse must be > 450ns 
+        self.i2c.write((self.i2c.read() & (~self.bit_e & 0xFF)))
+        self.delayMicroseconds(1)        # 1 microsecond pause - enable pulse must be > 450ns 
+
+    def write4bits(self, bits, char_mode=False):
+        """ Send command to LCD """
+
+        self.delayMicroseconds(1000) # 1000 microsecond sleep
+
+        if (char_mode):
+            self.i2c.write(self.i2c.read() | self.bit_rs)
+        else:
+            self.i2c.write(self.i2c.read() & (~self.bit_rs & 0xFF))
+
+        #print("0x%02X" % ((self.i2c.read() & 0xF0) | ((bits >> 4) & 0x0F)))
+        self.i2c.write((self.i2c.read() & 0xF0) | ((bits >> 4) & 0x0F))
+        self.pulseEnable()
+
+        #print("0x%02X" % ((self.i2c.read() & 0xF0) | (bits & 0x0F)))
+        self.i2c.write((self.i2c.read() & 0xF0) | (bits & 0x0F))
+        self.pulseEnable()
+
+
+def run_cmd(cmd):
+    p = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE)
+    output = p.communicate()[0]
+    return output
+
+if __name__ == '__main__':
+    lcd = Adafruit_CharLCD_I2C()
+    cmd = "ip addr show wlan0 | grep inet | awk '{print $2}' | cut -d/ -f1"
+
+    lcd.clear()
+    #lcd.message("  Adafruit 16x2\n  Standard LCD")
+
+    ipaddr = run_cmd(cmd)
+    lcd.message(datetime.datetime.now().strftime('%b %d  %H:%M:%S\n'))
+    lcd.message('IP %s' % ( ipaddr ) )