Hi allerseits,
ich habe gerade mein LCD DIsplay über i2c und i2c0 (da weiterer Sensor verbaut). Das Display wird auch erkannt, alles ok.
Wenn ich aber dann einen Testquellcode an das Display schicke, bekomme ich immer wieder Fehlermeldungen. Ich weiß dort nicht wirklich weiter.
Kann mir jemand weiterhelfen ? Ordner und LCD Adress passt auch.
lcddriver.py
import sys
sys.path.append("./lib")
import i2c_lib
from time import *
# LCD Address
ADDRESS = 0x27
# 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
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
# flags for backlight control
LCD_BACKLIGHT = 0x08
LCD_NOBACKLIGHT = 0x00
En = 0b00000100 # Enable bit
Rw = 0b00000010 # Read/Write bit
Rs = 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)HIer mein Testquellcode:
import lcddriver
import time
mylcd = lcddriver.lcd()
mylcd.lcd_clear()
while True:
mylcd.lcd_display_string("Time: %s" %time.strftime("%H:%M:%S"), 1)
mylcd.lcd_display_string("Date: %s" %time.strftime("%m/%d/%Y"), 2)Das kam bei raus:
Traceback (most recent call last):
File "anzeige.py", line 5, in <module>
mylcd = lcddriver.lcd()
File "/home/pi/Desktop/lcd_display/lcddriver.py", line 61, in __init__
self.lcd_write(0x03)
File "/home/pi/Desktop/lcd_display/lcddriver.py", line 85, in lcd_write
self.lcd_write_four_bits(mode | (cmd & 0xF0))
File "/home/pi/Desktop/lcd_display/lcddriver.py", line 80, in lcd_write_four_bits
self.lcd_device.write_cmd(data | LCD_BACKLIGHT)
File "/home/pi/Desktop/lcd_display/i2c_lib.py", line 13, in write_cmd
self.bus.write_byte(self.addr, cmd)
IOError: [Errno 121] Remote I/O error
Danke euch 
