-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathI2C_LDC_driver.py
179 lines (143 loc) · 4.88 KB
/
I2C_LDC_driver.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
# -*- coding: utf-8 -*-
# Original code found at:
# https://gist.github.com/DenisFromHR/cc863375a6e19dce359d
"""
Compiled, mashed and generally mutilated 2014-2015 by Denis Pleic
Made available under GNU GENERAL PUBLIC LICENSE
# Modified Python I2C library for Raspberry Pi
# as found on http://www.recantha.co.uk/blog/?p=4849
# Joined existing 'i2c_lib.py' and 'lcddriver.py' into a single library
# added bits and pieces from various sources
# By DenisFromHR (Denis Pleic)
# 2015-02-10, ver 0.1
"""
# i2c bus (0 -- original Pi, 1 -- Rev 2 Pi)
I2CBUS = 1
# LCD Address
ADDRESS = 0x27
import smbus
from time import sleep
class i2c_device:
def __init__(self, addr, port=I2CBUS):
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)
# 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_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))
# write a character to lcd (or character rom) 0x09: backlight | RS=DR<
# works!
def lcd_write_char(self, charvalue, mode=1):
self.lcd_write_four_bits(mode | (charvalue & 0xF0))
self.lcd_write_four_bits(mode | ((charvalue << 4) & 0xF0))
# put string function with optional char positioning
def lcd_display_string(self, string, line=1, pos=0):
if line == 1:
pos_new = pos
elif line == 2:
pos_new = 0x40 + pos
elif line == 3:
pos_new = 0x14 + pos
elif line == 4:
pos_new = 0x54 + pos
self.lcd_write(0x80 + pos_new)
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)
# define backlight on/off (lcd.backlight(1); off= lcd.backlight(0)
def backlight(self, state): # for state, 1 = on, 0 = off
if state == 1:
self.lcd_device.write_cmd(LCD_BACKLIGHT)
elif state == 0:
self.lcd_device.write_cmd(LCD_NOBACKLIGHT)
# add custom characters (0 - 7)
def lcd_load_custom_chars(self, fontdata):
self.lcd_write(0x40);
for char in fontdata:
for line in char:
self.lcd_write_char(line)