Adafruit_CircuitPython_CharLCD/adafruit_character_lcd/character_lcd.py
2017-11-15 16:42:07 -08:00

270 lines
9.2 KiB
Python

# The MIT License (MIT)
#
# Copyright (c) 2017 Brent Rubell for Adafruit Industries
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
"""
`adafruit_CircuitPython_CharLCD`
====================================================
TODO(description)
* Author(s):
-Brent Rubell
-Asher Lieber
-Tony DiCola for the original python charLCD library
"""
"""
`adafruit_character_lcd` - character lcd module
=================================================
module for interfacing with character lcds
"""
import time
import math
import digitalio
from board import *
# Commands
LCD_CLEARDISPLAY = const(0x01)
LCD_RETURNHOME = const(0x02)
LCD_ENTRYMODESET = const(0x04)
LCD_DISPLAYCONTROL = const(0x08)
LCD_CURSORSHIFT = const(0x10)
LCD_FUNCTIONSET = const(0x20)
LCD_SETCGRAMADDR = const(0x40)
LCD_SETDDRAMADDR = const(0x80)
# Entry flags
LCD_ENTRYRIGHT = const(0x00)
LCD_ENTRYLEFT = const(0x02)
LCD_ENTRYSHIFTINCREMENT = const(0x01)
LCD_ENTRYSHIFTDECREMENT = const(0x00)
# Control flags
LCD_DISPLAYON = const(0x04)
LCD_DISPLAYOFF = const(0x00)
LCD_CURSORON = const(0x02)
LCD_CURSOROFF = const(0x00)
LCD_BLINKON = const(0x01)
LCD_BLINKOFF = const(0x00)
# Move flags
LCD_DISPLAYMOVE = const(0x08)
LCD_CURSORMOVE = const(0x00)
LCD_MOVERIGHT = const(0x04)
LCD_MOVELEFT = const(0x00)
# Function set flags
LCD_8BITMODE = const(0x10)
LCD_4BITMODE = const(0x00)
LCD_2LINE = const(0x08)
LCD_1LINE = const(0x00)
LCD_5x10DOTS = const(0x04)
LCD_5x8DOTS = const(0x00)
# Offset for up to 4 rows.
LCD_ROW_OFFSETS = (0x00, 0x40, 0x14, 0x54)
class Character_LCD(object):
""" Interfaces with a character LCD
:param rs: The reset data line
:param en: The enable data line
:param d4, d5, d6, d7: The data lines 4 thru 7
:param cols: The columns on the charLCD
:param lines: The lines on the charLCD
:param backlight: The backlight pin, usually the last pin. Check with your datasheet
:param enable_pwm: The PWM CONTROL, TODO
:param initial_backlight: THE initial backlight status (on/off)
"""
def __init__(self, rs, en, d4, d5, d6, d7, cols, lines,
backlight = None,
enable_pwm = False,
initial_backlight = 1.0):
self.cols = cols
self.lines = lines
# save pin numbers
self.rs = rs
self.en = en
self.d4 = d4
self.d5 = d5
self.d6 = d6
self.d7 = d7
# backlight pin
self.backlight = backlight
# save backlight state
self.backlight = backlight
self.pwn_enabled = enable_pwm
# set all pins as outputs
for pin in(rs, en, d4, d5, d6, d7):
pin.direction = digitalio.Direction.OUTPUT
# Setup backlight
if backlight is not None:
self.backlight.direction = digitalio.Direction.OUTPUT
self.backlight.value = 0 # turn backlight on
# initialize the display
self._write8(0x33)
self._write8(0x32)
# init. display control
self.displaycontrol = LCD_DISPLAYON | LCD_CURSOROFF | LCD_BLINKOFF
# init display function
self.displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_2LINE | LCD_5x8DOTS
# init display mode
self.displaymode = LCD_ENTRYLEFT | LCD_ENTRYSHIFTDECREMENT
# write to display control
self._write8(LCD_DISPLAYCONTROL | self.displaycontrol)
# write displayfunction
self._write8(LCD_FUNCTIONSET | self.displayfunction)
# set the entry mode
self._write8(LCD_ENTRYMODESET | self.displaymode)
self.clear()
def home(self):
"""Moves the cursor back home pos(1,1)"""
self._write8(LCD_RETURNHOME)
time.sleep(0.003)
def clear(self):
"""Clears the LCD"""
self._write8(LCD_CLEARDISPLAY)
time.sleep(0.003)
def show_cursor(self, show):
"""Show or hide the cursor"""
if show:
self.displaycontrol |= LCD_CURSORON
else:
self.displaycontrol &= ~LCD_DISPLAYON
self._write8(LCD_DISPLAYCONTROL | self.displaycontrol)
def set_cursor(self, col, row):
"""Sets the cursor to ``row`` and ``col``
:param col: column location
:param row: row location
"""
# Clamp row to the last row of the display
if row > self.lines:
row = self.lines - 1
# Set location
self._write8(LCD_SETDDRAMADDR | (col + LCD_ROW_OFFSETS[row]))
def blink(self, blink):
"""Blinks the cursor if blink = true."""
if blink == True:
self.displaycontrol |= LCD_BLINKON
else:
self.displaycontrol &= ~LCD_BLINKON
self._write8(LCD_DISPLAYCONTROL | self.displaycontrol)
def move_left(self):
"""Moves display left one position"""
self._write8(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVELEFT)
def move_right(self):
"""Moves display right one position"""
self._write8(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVERIGHT)
def set_left_to_right(self):
"""Set direction of text to read from left to right"""
self.displaymode |= LCD_ENTRYLEFT
self._write8(LCD_ENTRYMODESET | self.displaymode)
def set_right_to_left(self):
"""Set direction of text to read from right to left"""
self.displaymode |= LCD_ENTRYLEFT
self._write8(LCD_ENTRYMODESET | self.displaymode)
def enable_display(self, enable):
"""Enable or disable the display. Set enable to True to enable."""
if enable:
self.displaycontrol |= LCD_DISPLAYON
else:
self.displaycontrol &= ~LCD_DISPLAYON
self._write8(LCD_DISPLAYCONTROL | self.displaycontrol)
def _write8(self,value, char_mode = False):
"""Sends 8b ``value`` in ``char_mode``.
:param value: bytes
:param char_mode: character/data mode selector. False (default) for
data only, True for character bits.
"""
# one ms delay to prevent writing too quickly.
time.sleep(0.001)
# set character/data bit. (charmode = False)
self.rs.value = char_mode
# WRITE upper 4 bits
self.d4.value = ((value >> 4) & 1) > 0
self.d5.value = ((value >> 5) & 1) > 0
self.d6.value = ((value >> 6) & 1) > 0
self.d7.value = ((value >> 7) & 1) > 0
# send command
self._pulse_enable()
# WRITE lower 4 bits
self.d4.value = (value & 1) > 0
self.d5.value = ((value >> 1) & 1) > 0
self.d6.value = ((value >> 2) & 1) > 0
self.d7.value = ((value >> 3) & 1) > 0
self._pulse_enable()
def _pulse_enable(self):
""" Pulses (lo->hi->lo) to send commands. """
self.en.value = False
# 1microsec pause
time.sleep(0.0000001)
self.en.value = True
time.sleep(0.0000001)
self.en.value = False
time.sleep(0.0000001)
def set_backlight(self, lighton):
""" Set lighton to turn the charLCD backlight on. """
if lighton:
self.backlight.value = 0
else:
self.backlight.value = 1
def message(self, text):
"""Write text to display, can include \n for newline"""
line = 0
# iterate thru each char
for char in text:
# if character is \n, go to next line
if char == '\n':
line += 1
# move to left/right depending on text direction
col = 0 if self.displaymode & LCD_ENTRYLEFT > 0 else self.cols-1
self.set_cursor(col, line)
# Write character to display
else:
self._write8(ord(char), True)
def create_char(self, location, pattern):
"""Fill one of the first 8 CGRAM locations with custom characters.
The location parameter should be between 0 and 7 and pattern should
provide an array of 8 bytes containing the pattern. E.g. you can easyly
design your custom character at http://www.quinapalus.com/hd44780udg.html
To show your custom character use eg. lcd.message('\x01')
"""
# only position 0..7 are allowed
location &= 0x7
self._write8(LCD_SETCGRAMADDR | (location << 3))
for i in range(8):
self._write8(pattern[i], char_mode=True)