User manual

Ausgabe 10.11.2017 Copyright by Joy-IT 7

def PulseEnableLine():

#Pulse the LCD Enable line; used for clocking in data

mSec = 0.0005 #use half-millisecond delay

time.sleep(mSec) #give time for inputs to settle

GPIO.output(LCD_E, GPIO.HIGH) #pulse E high

time.sleep(mSec)

GPIO.output(LCD_E, GPIO.LOW) #return E low

time.sleep(mSec) #wait before doing anything else

def SendNibble(data):

#sends upper 4 bits of data byte to LCD data pins D4-D7

GPIO.output(LCD_D4, bool(data & 0x10))

GPIO.output(LCD_D5, bool(data & 0x20))

GPIO.output(LCD_D6, bool(data & 0x40))

GPIO.output(LCD_D7, bool(data & 0x80))

def SendByte(data,charMode=False):

#send one byte to LCD controller

GPIO.output(LCD_RS,charMode) #set mode: command vs. char

SendNibble(data) #send upper bits first

PulseEnableLine() #pulse the enable line

data = (data & 0x0F)<< 4 #shift 4 bits to left

SendNibble(data) #send lower bits now

PulseEnableLine() #pulse the enable line

def InitLCD():

#initialize the LCD controller & clear display

SendByte(0x33) #initialize

SendByte(0x32) #set to 4-bit mode

SendByte(0x28) #2 line, 5x7 matrix

SendByte(0x0C) #turn cursor off (0x0E to enable)

SendByte(0x06) #shift cursor right

SendByte(CLEARDISPLAY) #remove any stray characters on display

########################################################################

def SendChar(ch):

SendByte(ord(ch),True)

def ShowMessage(string):

#Send string of characters to display at current cursor position

for character in string:

SendChar(character)

LCD Display 20x4 mit Buttons