Portexpander

Portexpander 8591 (4 AI, 1 AO)

#!/usr/bin/python3#Mit diesem Programm wird ein über den I2C Bus angeschlossener Expander ausgelesen und angesteuert#Schwellwert mittels Poti einstellen#Es handelt sich um den Portexpander 8591 mit 4 AI und 1 AOimport smbus, time
bus = smbus.SMBus(1)Portexpander = 0x48 #Adresse des Portexpanders
def get(register): read = bus.read_byte_data(Portexpander, 0x40+register) time.sleep(0.01) read = bus.read_byte_data(Portexpander, 0x40+register) return read
def set(register, daten): write = bus.write_byte_data(Portexpander, 0x40+register, daten) #0x40 steht dabei als Grundvoraussetzung, dass AnalogOut aktiviert ist. return
Wiedergabe = False #Hilfsvariableset(3, 180) #Analogen Ausgang setzen
while True: print("Ain0: ",get(0),"Ain1: ",get(1),"Ain2: ",get(2),"Ain3 ",get(3)) if get(3) < 150 and Wiedergabe == False: Wiedergabe = True print("Schwellwert erreicht") elif (get(3) > 200): Wiedergabe = False print("Schwellwert überschritten") time.sleep(0.5)
#AIn0 = LDR#AIn1 = Unbelegt#AIn2 = Temperaturfühler#AIn3 = Potentiometer#AOut = LED

Expander PCF8574 als Display Treiber

In der Datei lcddriver.py muss die Adresse des I2C Expanders für das Display eingestellt werden

Hinweis: Die Hintergrundbeleuchtung Ein-/Ausschalten funktioniert bei mir nicht, da es auf meinem Modul durch einen Jumper realisiert wird.

Display.py:

import lcddriverimport time
def LCDText(t1, t2): lcd.lcd_clear() lcd.lcd_display_string(t1, 1) lcd.lcd_display_string(t2, 2)
lcd = lcddriver.lcd()lcd.lcd_clear()time.sleep(2)lcd.lcd_display_string("Erster Versuch",1)time.sleep(2)
lcd.lcd_backlight("Off")lcd.lcd_clear()lcd.lcd_display_string("Zeile 1", 1)lcd.lcd_display_string("Zeile 2", 2)
time.sleep(2)LCDText("Messwert", "Nichtsda")
time.sleep(2)LCDText("Temperatur in "+chr(223) +"C", "21,0")

i2c_lib.py:

import syssys.path.append("./lib")import smbusfrom time import *
class i2c_device: def __init__(self, addr, port=1): 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)

lcddriver.py:

import syssys.path.append("./lib")
import i2c_libfrom time import *
# LCD AddressADDRESS = 0x27 #Hier die Adresse einstellen
# commandsLCD_CLEARDISPLAY = 0x01LCD_RETURNHOME = 0x02LCD_ENTRYMODESET = 0x04LCD_DISPLAYCONTROL = 0x08LCD_CURSORSHIFT = 0x10LCD_FUNCTIONSET = 0x20LCD_SETCGRAMADDR = 0x40LCD_SETDDRAMADDR = 0x80
# flags for display entry modeLCD_ENTRYRIGHT = 0x00LCD_ENTRYLEFT = 0x02LCD_ENTRYSHIFTINCREMENT = 0x01LCD_ENTRYSHIFTDECREMENT = 0x00
# flags for display on/off controlLCD_DISPLAYON = 0x04LCD_DISPLAYOFF = 0x00LCD_CURSORON = 0x02LCD_CURSOROFF = 0x00LCD_BLINKON = 0x01LCD_BLINKOFF = 0x00
# flags for display/cursor shiftLCD_DISPLAYMOVE = 0x08LCD_CURSORMOVE = 0x00LCD_MOVERIGHT = 0x04LCD_MOVELEFT = 0x00
# flags for function setLCD_8BITMODE = 0x10LCD_4BITMODE = 0x00LCD_2LINE = 0x08LCD_1LINE = 0x00LCD_5x10DOTS = 0x04LCD_5x8DOTS = 0x00
# flags for backlight controlLCD_BACKLIGHT = 0x08LCD_NOBACKLIGHT = 0x00
En = 0b00000100 # Enable bitRw = 0b00000010 # Read/Write bitRs = 0b00000001 # Register select bit
class lcd: #initializes objects and lcd def __init__(self): self.lcd_device = i2c_lib.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)) #turn on/off the lcd backlight def lcd_backlight(self, state): if state in ("on","On","ON"): self.lcd_device.write_cmd(LCD_BACKLIGHT) elif state in ("off","Off","OFF"): self.lcd_device.write_cmd(LCD_NOBACKLIGHT) else: print ("Unknown State!")
# put string function def lcd_display_string(self, string, line): if line == 1: self.lcd_write(0x80) if line == 2: self.lcd_write(0xC0) if line == 3: self.lcd_write(0x94) if line == 4: self.lcd_write(0xD4)
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)

Sonderzeichen für LCD Display - Quelle: https://www.mikrocontroller.net/topic/293125 vom 30.12.2019

lcd.print("R\365cklauf"); //wird dargestellt als" Rücklauf"

\40 !

\41 "

\42 #

\43 $

\44 %

\45 &

\50 (

\51 )

\52 *

\53 Plus-Zeichen

\54 Komma

\55 Minus-Zeichen

\56 Punkt

\57 Schrägstrich

\72 Doppelpunkt

\73 Semikolon

\74 <

\75 Gleichheitszeichen

\76 >

\77 ?

\100 @

\134 eckige Klammer links

\136 eckige Klammer rechts

\137 accent circonflexe

\138 Unterstrich

\140 accent grave

\173 geschweifte Klammer links

\174 senkrechter Strich

\175 geschweifte Klammer rechts

\176 Pfeil nach rechts

\177 Pfeil nach links

\260 Minuszeichen

\333 Kastenrahmen

\337 hochgestellter Kastenrahmen(wie Potenz)

\340 gr. alpha

\341 ä

\342 ß

\343 klein epsilon

\344 µ

\350 Wurzelzeichen

\351 hoch minus 1

\353 hoch x

\356 n mit Oberstrich ( spanisch )

\357 ö

\363 Zeichen unendlich

\364 Ohm

\365 ü

\366 gr.Summe

\367 pi ( klein )

\371 u mit strich rechts unten

\375 geteilt durch

\377 alle Leuchtpunkte eingeschaltet

Einfaches Menü erstellen:

import lcddriverimport time
m_Alt = 99menu = 0
def LCDText(t1, t2): lcd.lcd_clear() lcd.lcd_display_string(t1, 1) lcd.lcd_display_string(t2, 2)
lcd = lcddriver.lcd()LCDText("Einfaches Men\365", "")time.sleep(2)
while(True): if(menu != m_Alt): if(menu == 0): LCDText("Messwert", "n. vorhanden") elif(menu == 1): LCDText("Temperatur in "+chr(223) +"C", "21,0") elif(menu == 2): LCDText("Wie geht es ", "dir?") elif(menu == 3): LCDText("Sonderzeichen", "\341\357\365\342\350\366")

m_Alt = menu menu = int(input("Welches Menü soll aufgerufen werden? "))

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