HD44780

#!/usr/bin/python

import RPi.GPIO as GPIO
from time import sleep, strftime, localtime

class HD44780:
    def __init__(self):
        # Deklaracja zmiennych. Numeracja pinow wedlug BCM
        self.LCD_RS = 7
        self.LCD_E  = 8
        self.LCD_D4 = 25
        self.LCD_D5 = 24
        self.LCD_D6 = 23
        self.LCD_D7 = 2

        # Inicjalizacja pinow GPIO
        GPIO.setwarnings(False)
        GPIO.setmode(GPIO.BCM)
        GPIO.setup(self.LCD_E, GPIO.OUT)  # E
        GPIO.setup(self.LCD_RS, GPIO.OUT) # RS
        GPIO.setup(self.LCD_D4, GPIO.OUT) # DB4
        GPIO.setup(self.LCD_D5, GPIO.OUT) # DB5
        GPIO.setup(self.LCD_D6, GPIO.OUT) # DB6
        GPIO.setup(self.LCD_D7, GPIO.OUT) # DB7

        # Zresetowanie pinow
        GPIO.output(self.LCD_E, False)
        GPIO.output(self.LCD_RS, False)
        GPIO.output(self.LCD_D4, False)
        GPIO.output(self.LCD_D5, False)
        GPIO.output(self.LCD_D6, False)
        GPIO.output(self.LCD_D7, False)

    def init(self):
        # Przygotowanie ekranu
        self._write(0x33)
        self._write(0x32)
        self._write(0x28) # Przesylanie danych w 4 bitach, 2 linie, 5x7 pikseli
        self._write(0x0C) # Nie wyswietlaj kursora
        self._write(0x06) # Tryb wpisywania (Normalny, od lewej do prawej)
        self._write(0x01) # Wyczyszczenie znakow

        # Pozycje wlasnych znakow
        self.LCD_TAB_CHARS = [0x40,0x48,0x50,0x58,0x60,0x68,0x70,0x78]

        self.customChar(0,[0x00, 0x00, 0x04, 0x0E, 0x1F, 0x00, 0x00, 0x00]) # ARROW UP
        self.customChar(1,[0x00, 0x00, 0x00, 0x1F, 0x0E, 0x04, 0x00, 0x00]) # ARROW DOWN
        self.customChar(2,[0x1F, 0x1F, 0x1B, 0x15, 0x0E, 0x1F, 0x1F, 0x1F]) # ARROW UP NEG
        self.customChar(3,[0x1F, 0x1F, 0x1F, 0x0E, 0x15, 0x1B, 0x1F, 0x1F]) # ARROW DOWN NEG
    def _write(self, bits, char_mode=False):
        bits=bin(bits)[2:].zfill(8)

        # Tryb wpisywania komend/znakow
        GPIO.output(self.LCD_E, False)
        GPIO.output(self.LCD_RS, char_mode)

        # Wpisanie pierwszych 4 bitow
        GPIO.output(self.LCD_D4, int(bits[3]))
        GPIO.output(self.LCD_D5, int(bits[2]))
        GPIO.output(self.LCD_D6, int(bits[1]))
        GPIO.output(self.LCD_D7, int(bits[0]))
        # Odebranie ich przez LCD
        GPIO.output(self.LCD_E, True)
        sleep(0.00000045)
        GPIO.output(self.LCD_E, False)

        # Odczekanie wymaganego czasu
        if char_mode:
            sleep(0.0002)
        else:
            sleep(0.005)

        # Wpisanie kolejnych 4 bitow
        GPIO.output(self.LCD_D4, int(bits[7]))
        GPIO.output(self.LCD_D5, int(bits[6]))
        GPIO.output(self.LCD_D6, int(bits[5]))
        GPIO.output(self.LCD_D7, int(bits[4]))
        # Odebranie ich przez LCD
        GPIO.output(self.LCD_E, True)
        sleep(0.00000045)
        GPIO.output(self.LCD_E, False)

        # Odczekanie wymaganego czasu
        if char_mode:
            sleep(0.0002)
        else:
            sleep(0.005)
    def customChar(self,pos,char):
        self._write(self.LCD_TAB_CHARS[pos])
        for i in char:
            self._write(i,True)
    def writeChar(self, char):
        self._write(ord(char),True)
    def writeMsg(self, text, time=0):
        self.home()
        for char in text:
            if char == '\n': # NEW LINE
                self._write(0xC0)
            elif char == '\a': # ARROW UP
                sleep(time)
                self.writeChar(chr(0))
            elif char == '\b': # ARROW DOWN
                sleep(time)
                self.writeChar(chr(1))
            elif char == '\f': # ARROW UP NEG
                sleep(time)
                self.writeChar(chr(2))
            elif char == '\t': # ARROW DOWN NEG
                sleep(time)
                self.writeChar(chr(3))
            else:
                sleep(time)
                self.writeChar(char)
    def setChar(self,line,column,newchar):
        self._write(0x02) # Powrot kursora na poczatek
        for index in range(line-1):
            self._write(0xC0)
        for index in range(column-1):
            self._write(0x14)
        self.writeChar(newchar)

    def test(self):
        self.writeMsg("Hello! :)",0.25)
        sleep(2)
        for index in range(5):
            self.writeMsg("Local time:\n"+strftime("%H:%M:%S", localtime()))
            sleep(1)
        self.writeMsg("Today's date:\n"+strftime("%Y-%m-%d", localtime()))
        sleep(2)
        cpu_temp = open( "/sys/class/thermal/thermal_zone0/temp" ).read()
        self.clear()
        self.writeMsg("CPU Temp:\n"+str(float(cpu_temp)/1000)+"C")


    def clear(self):        # Clear display
        self._write(0x01)
    def scrollRight(self):  # Move all characters right
        self._write(0x1E)
    def scrollLeft(self):   # Move all characters left
        self._write(0x18)
    def blank(self):        # Hide all characters
        self._write(0x08)
    def restore(self):      # Show all characters
        self._write(0x0C)

    def home(self):         # Move cursor to left, top corner
        self._write(0x02)
    def cursorRight(self):  # Move cursor one place right
        self._write(0x02)
    def cursorLeft(self):   # Move cursor one place left
        self._write(0x02)
    def cursorDown(self):   # Move cursor one line down
        self._write(0x02)

    def cleanup(self):      # Clear LCD and restore GPIO to default
        self.clear()
        GPIO.cleanup()