265 lines
7 KiB
Python
265 lines
7 KiB
Python
|
#!/usr/bin/env 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
|
||
|
#
|
||
|
|
||
|
from time import sleep
|
||
|
|
||
|
class Adafruit_CharLCD:
|
||
|
|
||
|
# 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, pin_rs=24, pin_e=23, pins_db=[17, 18, 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.setwarnings(False)
|
||
|
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)
|
||
|
|
||
|
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 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 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()
|
||
|
|
||
|
|
||
|
def delayMicroseconds(self, microseconds):
|
||
|
seconds = microseconds / float(1000000) # divide microseconds by 1 million for seconds
|
||
|
sleep(seconds)
|
||
|
|
||
|
|
||
|
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 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)
|
||
|
|
||
|
def loop():
|
||
|
lcd = Adafruit_CharLCD()
|
||
|
while True:
|
||
|
print("loop")
|
||
|
lcd.clear()
|
||
|
lcd.message(" LCD 1602 Test \n123456789ABCDEF")
|
||
|
sleep(2)
|
||
|
|
||
|
if __name__ == '__main__':
|
||
|
loop()
|