Add LCD 16x02 support #3
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import time
from gpiozero import DigitalOutputDevice
def msleep(milliseconds):
"""Sleep the specified amount of milliseconds."""
time.sleep(milliseconds / 1000.0)
def usleep(microseconds):
"""Sleep the specified amount of microseconds."""
time.sleep(microseconds / 1000000.0)
class Commands(object):
"""
For details:
- http://www.microcontrollerboard.com/lcd.html
- https://www.sparkfun.com/datasheets/LCD/HD44780.pdf
int CLEAR: Clears entire display and sets DDRAM address 0 in address counter.
int RETURN_HOME: Sets DDRAM address 0 in address counter.
Also returns display from being shifted to original position.
DDRAM contents remain unchanged.
int ENTRY_MODE_SET: Sets
- Cursor move direction - MODE_INCREMENT (left to right) or MODE_DECREMENT (right to left)
- Specifies display shift - ACCOPANIES_DISPLAY_SHIFT or NOT_ACCOPANIES_DISPLAY_SHIFT
These operations are performed during data write and read.
int DISPLAY_ON_OFF_CONTROL: Sets
- entire display on/off - DISPLAY_ON or DISPLAY_OFF
- cursor on/off - CURSOR_ON or CURSOR_OFF
- blinking of cursor position character (B).
int CURSOR_OR_DISPLAY_SHIFT: Moves cursor and shifts display without changing
DDRAM contents.
int FUNCTION_SET: Sets:
- interface data length (DL),
- number of display lines - ONE_ROW or TWO_ROWS
- and character font - CHARACTER_5x7 or CHARACTER_5x10
"""
CLEAR = 0x01
RETURN_HOME = 0x02
ENTRY_MODE_SET = 0x04
MODE_INCREMENT = 0b0010
MODE_DECREMENT = 0b0000
ACCOPANIES_DISPLAY_SHIFT = 0b0001
NOT_ACCOPANIES_DISPLAY_SHIFT = 0b0000
DISPLAY_ON_OFF_CONTROL = 0x08
DISPLAY_ON = 0b0100
DISPLAY_OFF = 0b0000
CURSOR_ON = 0b0010
CURSOR_OFF = 0b0000
BLINKING_ON = 0b0001
BLINKING_OFF = 0b0000
CURSOR_OR_DISPLAY_SHIFT = 0x10
DISPLAY_SHIFT = 0b1000
CURSOR_MOVE = 0b0000
MOVE_CURSOR_RIGHT = 0b0100
MOVE_CURSOR_LEFT = 0b0000
FUNCTION_SET = 0x20
ONE_ROW = 0b0000
TWO_ROWS = 0b1000
CHARACTER_5x7 = 0b0000
CHARACTER_5x10 = 0b0100
ROWS = [0x80, 0xC0, 0x94, 0xD4]
class LCD8Pins(object):
def __init__(self, LCD):
self.LCD = LCD
def initialize_display(self):
msleep(50)
self.LCD.rs.off()
self.LCD.rw.off()
self._write_4bits(0x03)
msleep(4.5)
self._write_4bits(0x03)
usleep(100)
self._write_4bits(0x03)
usleep(100)
def write_byte(self, byte):
self.LCD.enable.off()
self._write_pins(data)
usleep(2)
self.LCD.enable.on()
usleep(5)
self.LCD.enable.off()
def _write_pins(self, data):
self.db7.value = (data & 0b10000000) >> 7 == 1
self.db6.value = (data & 0b01000000) >> 6 == 1
self.db5.value = (data & 0b00100000) >> 5 == 1
self.db4.value = (data & 0b00010000) >> 4 == 1
self.db7.value = (data & 0b00001000) >> 3 == 1
self.db6.value = (data & 0b00000100) >> 2 == 1
self.db5.value = (data & 0b00000010) >> 1 == 1
self.db4.value = (data & 0b00000001) == 1
class LCD4Pins(object):
def __init__(self, LCD):
self.LCD = LCD
def initialize_display(self):
msleep(50)
self.LCD.rs.off()
self.LCD.rw.off()
self._write_4bits(0x03)
msleep(4.5)
self._write_4bits(0x03)
usleep(100)
self._write_4bits(0x03)
self._write_4bits(0x02)
usleep(100)
def write_byte(self, byte):
self._write_4bits(byte >> 4)
self._write_4bits(byte)
def _write_4bits(self, data):
self.LCD.enable.off()
self._write_pins(data)
usleep(2)
self.LCD.enable.on()
usleep(5)
self.LCD.enable.off()
def _write_pins(self, data):
self.LCD.db7.value = (data & 0b00001000) >> 3 == 1
self.LCD.db6.value = (data & 0b00000100) >> 2 == 1
self.LCD.db5.value = (data & 0b00000010) >> 1 == 1
self.LCD.db4.value = (data & 0b00000001) == 1
class LiquidCrystal(object):
"""
Based in https://www.sparkfun.com/datasheets/LCD/HD44780.pdf
"""
def __init__(self):
self.strategy = LCD4Pins(self)
self._init_pins()
self._init_status()
self._init_display()
def _init_pins(self):
self.db7 = DigitalOutputDevice(18)
self.db6 = DigitalOutputDevice(15)
self.db5 = DigitalOutputDevice(14)
self.db4 = DigitalOutputDevice(4)
#self.db3 = DigitalOutputDevice()
#self.db2 = DigitalOutputDevice()
#self.db1 = DigitalOutputDevice()
#self.db0 = DigitalOutputDevice()
self.rs = DigitalOutputDevice(2)
self.rw = DigitalOutputDevice(6)
self.enable = DigitalOutputDevice(3)
def _init_status(self):
self.rows = 2
self.columns = 16
self.content = [[' '] * self.columns for _ in range(self.rows)]
self.row = 0
self.column = 0
self._entry_mode_set = Commands.DISPLAY_ON_OFF_CONTROL | Commands.DISPLAY_ON | Commands.CURSOR_ON | Commands.BLINKING_ON
def _init_display(self):
self.strategy.initialize_display()
self.command(Commands.FUNCTION_SET | Commands.TWO_ROWS | Commands.CHARACTER_5x7)
self.command(Commands.CURSOR_OR_DISPLAY_SHIFT | Commands.CURSOR_MOVE | Commands.MOVE_CURSOR_LEFT)
self.clear()
self.command(self._entry_mode_set)
def command(self, command):
"""
Send a command to display
Please, use Commands static attributes to splicit code
"""
self._write_data(True, command)
def data(self, char):
"""
Send data to display
If you request send text, please, use self.write() method
"""
self._write_data(False, char)
def _write_data(self, is_command, byte):
self.rs.value = not is_command
self.strategy.write_byte(byte)
usleep(50) # HD44780: > 37us
def _write_byte(self, data):
self.strategy.write_byte(data)
def write(self, string, row=None, column=None):
if row is not None and column is not None:
self.position = (row, column)
for char in string:
byte_char = ord(char)
self.data(byte_char)
self.content[self.row][self.column] = byte_char
@property
def position(self):
return (self.row, self.column)
@position.setter
def position(self, position):
self.row, self.column = position[0], position[1]
data = Commands.ROWS[row] | column
self.command(data)
def clear(self):
self.row = 0
self.column = 0
self.content = [[None] * self.columns for _ in range(self.rows)]
self.command(Commands.CLEAR)
msleep(2) # Clear requests more time than anothers commands
def home(self):
"""Return to initial position (row=0, column=0)"""
self.row = 0
self.column = 0
command(Commands.RETURN_HOME);
msleep(2) # Got to home requests more time than anothers commands
@property
def visible(self):
"""return bool: Is display visible?"""
return ByteUtil.is_flag_active(self._entry_mode_set, Commands.DISPLAY_ON)
@visible.setter
def visible(self, status):
"""Turn the display on/off (quickly)"""
self._entry_mode_set = ByteUtil.apply_flag(self._entry_mode_set, Commands.DISPLAY_ON, status)
self.command(self._entry_mode_set)
@property
def cursor(self):
"""return bool: Is underline cursor visible?"""
return ByteUtil.is_flag_active(self._entry_mode_set, Commands.CURSOR_ON)
@cursor.setter
def cursor(self, status):
"""Turn underline cursor visibility on/off"""
self._entry_mode_set = ByteUtil.apply_flag(self._entry_mode_set, Commands.CURSOR_ON, status)
self.command(self._entry_mode_set)
@property
def blink(self):
"""return bool: Is cursor blinking enabled?"""
return ByteUtil.is_flag_active(self._entry_mode_set, Commands.BLINKING_ON)
@blink.setter
def blink(self, status):
"""Turn blink cursor visibility on/off"""
self._entry_mode_set = ByteUtil.apply_flag(self._entry_mode_set, Commands.BLINKING_ON, status)
self.command(self._entry_mode_set)
@property
def string_content(self):
content = ''
for row in self.content:
for byte_char in row:
row += chr(byte_char)
content += '\n'
return content
"""
void LiquidCrystal::scrollDisplayLeft(void) {
command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVELEFT);
}
void LiquidCrystal::scrollDisplayRight(void) {
command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVERIGHT);
}
"""
class ByteUtil(object):
@staticmethod
def apply_flag(byte, flag, status):
if status:
byte |= flag
else:
byte &= ~flag
return byte
def is_flag_active(byte, flag):
return (byte & flag) != 0
display = LiquidCrystal()
while True:
display.write("Teste ", 0, 0)
'''
display.write(" ", 1, 0)
time.sleep(4)
display.write("Pedal Pi", 0, 0)
time.sleep(4)
display.write(" O Leo ligou os ", 0, 0)
display.write(" direito? ", 1, 0)
time.sleep(4)
'''
display.cursor = False
display.blink = True
for row in range(2):
for column in range(16):
display.position = (row, column)
time.sleep(0.2)
display.cursor = True
display.blink = False
for row in range(2):
for column in range(16):
display.position = (row, column)
time.sleep(0.2)
display.visible = False
time.sleep(2)
display.visible = True |
SrMouraSilva
added a commit
that referenced
this issue
Oct 1, 2016
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Description
Add LCD 16x02 display support
Steps
Cursor left/rightUsesliquid_crystal.positionMaterial
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