pertelian/pertelian.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

# ---------------------------------------------------------------------
# pertelian.py: python module to control Pertelian X2040 USB LCD
# ---------------------------------------------------------------------
# Copyright (c) 2019 BOXTEC AG <src@boxtec.ch>
#
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. The name of the author may not be used to endorse or promote products
#    derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
# INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
# AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
# THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
# OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
# OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
# ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
# --------------------------------------------------------------------------
#


"""
__author__  = "boxtec (src@boxtec.ch)"
__appname__ = "pertelian.py"
__version__ = "1.00"
__date__    = "2019-04-17"
__license__ = "BSD"
"""


#######################
# IMPORTS
#######################
import serial, time, struct

#######################
# CONSTANTS
#######################
LCD_WIDTH = 20
STRING_WIDTH = 20
SDELAY_DEFAULT = 0.01
#DEFAULT_INIT = [0x38, 0x06, 0x10, 0x0c, 0x01]
DEFAULT_INIT = [0x38, 0x06, 0x10, 0x0c, 0x01]
FILLER_CHAR = " "

#######################
# Display class
#######################
class Display():
  
  # local methods
  def __init__(self, port='/dev/ttyUSB0', baudrate=115200, init_seq=DEFAULT_INIT):
    self._sp = serial.Serial(port, baudrate)
    self._display_init(init_seq)
    
    self.backlight(True)
    self.enable()
  
  def __del__(self):
    self._sp.close()


  def _display_init(self, init_seq):
    for cmd in init_seq:
      self._sendcmd(cmd)
    
  
  def _senddata(self, data, datatype="C", delay=SDELAY_DEFAULT):
    for c in data:
      self._sp.write(chr(c))
      time.sleep(delay)
      

  def _sendcmd(self, cmd, delay=SDELAY_DEFAULT):
    cmd_data = (0xfe, cmd)
    self._senddata(cmd_data, delay)
    
  
  # public methods
  def enable(self):
    self._sendcmd(0x0c)
    
    
  def disable(self):
    self.clear()
    self.backlight(False)
    self._sendcmd(0x08)
    
    
  def backlight(self, on=True):
    if on:
      self._sendcmd(0x03)
    else:
      self._sendcmd(0x02)
  
  
  def clear(self):
    self._sendcmd(0x01)
    
    
  def lcdprintln(self, text):
    char_list = []
    for c in text:
      char_list.append(ord(c))
      if len(char_list) >= 20: break
    while len(char_list) < STRING_WIDTH:
      char_list.append(ord(FILLER_CHAR))
    self._senddata(char_list)


  def lcdprint(self, text):
    char_list = []
    for c in text:
      char_list.append(ord(c))
    self._senddata(char_list)

      
  def lcdcursor_set(self, line, position):
    #Row1-4 baseaddress: 
    rowbase = [0x0, 0x40, 0x14, 0x54]
    self._sendcmd((rowbase[line-1] + position) | 0x80)


  def lcdscroll(self, text="", scroll_delay=0.1, iterations=1):
    if len(text) > 0:
      lcdprintln(text)
    for c in range(0, iterations):
      for i in range(0, STRING_WIDTH):
        self._sendcmd(0x1c)
        time.sleep(scroll_delay)