Configuration details for LCDproc and/or Raspbmc can be found here : http://www.raspberrypi.org/forum/viewto ... 35&t=63412
SSH into the pi and install smbus and i2c-tools :
Code: Select all
sudo apt-get update
sudo apt-get install python-smbus i2c-tools -yCode: Select all
sudo nano /etc/modulesCode: Select all
i2c-bcm2708
i2c-devCode: Select all
sudo nano /etc/modprobe.d/raspi-blacklist.confCode: Select all
#blacklist i2c-bcm2708Code: Select all
sudo rebootCode: Select all
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# working 24/11/13
# with backlight control
# and auto Pi Rev detection
import smbus
from time import *
import RPi.GPIO as GPIO
BackLight = True # LCD backlight enable
Revision = 0 # Pi revision
UP=0
LEFT=0
DOWN=0
RIGHT=0
SELECT=0
# General i2c device class so that other devices can be added easily
class i2c_device:
def __init__(self, addr, port):
self.addr = addr
self.bus = smbus.SMBus(port)
def write(self, byte):
if (BackLight == False):
byte = byte & 0x7F # switch off backlight LED
else:
byte = byte | 0x80 # switch on backlight LED
self.bus.write_byte(self.addr, byte)
def read(self):
return self.bus.read_byte(self.addr)
def read_nbytes_data(self, data, n): # For sequential reads > 1 byte
return self.bus.read_i2c_block_data(self.addr, data, n)
class lcd:
#initializes objects and lcd
'''
pinout is as follows: PCF8574 - HD44780
P0 - LCD11 - D4
P1 - LCD12 - D5
P2 - LCD13 - D6
P3 - LCD14 - D7
P4 - LCD4 - RS
P5 - LCD5 - R/W
P6 - LCD6 - E
P7 - LCD15 - LED BACKLIGHT
'''
def __init__(self, addr, port):
self.lcd_device = i2c_device(addr, port)
self.lcd_device.write(0x03)
self.lcd_strobe()
sleep(0.0005)
self.lcd_strobe()
sleep(0.0005)
self.lcd_strobe()
sleep(0.0005)
self.lcd_device.write(0x02)
self.lcd_strobe()
sleep(0.0005)
self.lcd_write(0x28)
self.lcd_write(0x08)
self.lcd_write(0x01)
self.lcd_write(0x06)
self.lcd_write(0x0C)
self.lcd_write(0x01)
# clocks EN to latch command
def lcd_strobe(self):
self.lcd_device.write((self.lcd_device.read() | 0x40))
self.lcd_device.write((self.lcd_device.read() & 0xbF))
# write a command to lcd
def lcd_write(self, cmd):
self.lcd_device.write((cmd >> 4))
hi= self.lcd_device.read()
self.lcd_strobe()
self.lcd_device.write((cmd & 0x0F))
lo= self.lcd_device.read()
self.lcd_strobe()
self.lcd_device.write(0x0)
# print 'cmd',cmd,hi,lo
# write a character to lcd (or character rom)
def lcd_write_char(self, charvalue):
# print "char",charvalue
self.lcd_device.write((0x10 | (charvalue >> 4)))
self.lcd_strobe()
self.lcd_device.write((0x10 | (charvalue & 0x0F)))
self.lcd_strobe()
self.lcd_device.write(0x0)
# put char function
def lcd_putc(self, char):
self.lcd_write_char(ord(char))
# put string function
def lcd_puts(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_putc(char)
# clear lcd and set to home
def lcd_clear(self):
self.lcd_write(0x1)
self.lcd_write(0x2)
# add custom characters (0 - 7)
def lcd_load_custon_chars(self, fontdata):
self.lcd_device.bus.write(0x40);
for char in fontdata:
for line in char:
self.lcd_write_char(line)
def test(self):
print("")
print("toggle E x 10")
for i in range(10):
print(".")
self.lcd_device.write((self.lcd_device.read() | 0x40))
sleep(1)
self.lcd_device.write((self.lcd_device.read() & 0xbF))
sleep(1)
print("")
print("toggle RS x 10")
for i in range(10):
print(".")
self.lcd_device.write((self.lcd_device.read() | 0x10))
sleep(1)
self.lcd_device.write((self.lcd_device.read() & 0xEF))
sleep(1)
def get_revision():
with open('/proc/cpuinfo') as lines:
for line in lines:
if line.startswith('Revision'):
return int(line[line.index(':') + 1:], 16) & 0xFFFF
raise RuntimeError('No revision found.')
def get_board_revision():
revision = get_revision()
if revision in (2, 3):
return 1
else:
return 2
def gpio_setup():
global UP, DOWN, LEFT, RIGHT, SELECT
if Revision==1:
RIGHT=21
else:
RIGHT=27
SELECT=4
DOWN=17
UP=22
LEFT=23
GPIO.setmode(GPIO.BCM) # set up BCM GPIO numbering
GPIO.setup(SELECT, GPIO.IN, pull_up_down=GPIO.PUD_DOWN) # set as input (Select button)
GPIO.setup(UP, GPIO.IN, pull_up_down=GPIO.PUD_DOWN) # set as input (Up button)
GPIO.setup(DOWN, GPIO.IN, pull_up_down=GPIO.PUD_DOWN) # set as input (Down button)
GPIO.setup(RIGHT, GPIO.IN, pull_up_down=GPIO.PUD_DOWN) # set as input (Right button)
GPIO.setup(LEFT, GPIO.IN, pull_up_down=GPIO.PUD_DOWN) # set as input (Left button)
def main():
global Revision
Revision = get_board_revision()
print "get board revision=",Revision
if Revision==1:
i2cbus=0
else:
i2cbus=1
print "i2cbus=",i2cbus
device = lcd(0x20,i2cbus)
gpio_setup()
device.lcd_clear()
device.lcd_puts("abcdefghijklmnopqrst",1)
device.lcd_puts("1234567890abcdefghij",2)
device.lcd_puts("ABCDEFGHIJKLMNOPQRST",3)
device.lcd_puts("Line 4 - Hello !!!!!",4)
sleep(3)
device.lcd_clear()
while True:
if GPIO.input(SELECT): # if port 4 == 1
device.lcd_puts("SELECT pressed ",1)
print "SELECT is 1/HIGH/True"
if GPIO.input(UP):
break # quit if SELECT an UP pressed at the same time
elif GPIO.input(DOWN): # if port 17 == 1
device.lcd_puts("DOWN pressed ",1)
print "DOWN is 1/HIGH/True"
elif GPIO.input(RIGHT): # if port 21 or 27== 1
device.lcd_puts("RIGHT pressed ",1)
print "RIGHT is 1/HIGH/True"
elif GPIO.input(UP): # if port 22 == 1
device.lcd_puts("UP pressed ",1)
print "UP is 1/HIGH/True"
elif GPIO.input(LEFT): # if port 23 == 1
device.lcd_puts("LEFT pressed ",1)
print "LEFT is 1/HIGH/True"
else:
device.lcd_puts("No button pressed",1)
if __name__ == '__main__':
main()
Texy
