Instruction Guide LCD/OLED display using pydPiper

Code:
#!/usr/bin/python

# -*- coding: utf-8 -*-

#--------------------------------------

#

# The LCD Driver portion of this code

# created by:

#    ___  ___  _ ____

#   / _ \/ _ \(_) __/__  __ __

#  / , _/ ___/ /\ \/ _ \/ // /

# /_/|_/_/  /_/___/ .__/\_, /

#                /_/   /___/

#

#  lcd_16x2.py

#  20x4 LCD Test Script with

#  backlight control and text justification

#

# Author : Matt Hawkins

# Date   : 06/04/2015

#

# https://www.raspberrypi-spy.co.uk/

#--------------------------------------

#

# The Moode audio portion of the code

# created by:

#

# Author : Bryce Jeannotte

# Date   : 08/31/2017

#

#--------------------------------------

# The wiring for the LCD is as follows:

# 1 : GND

# 2 : 5V

# 3 : Contrast (0-5V)*

# 4 : RS (Register Select)

# 5 : R/W (Read Write)       - GROUND THIS PIN

# 6 : Enable or Strobe

# 7 : Data Bit 0             - NOT USED

# 8 : Data Bit 1             - NOT USED

# 9 : Data Bit 2             - NOT USED

# 10: Data Bit 3             - NOT USED

# 11: Data Bit 4

# 12: Data Bit 5

# 13: Data Bit 6

# 14: Data Bit 7

# 15: LCD Backlight +5V**

# 16: LCD Backlight GND

 

#import

import os

import RPi.GPIO as GPIO

import time



# Define GPIO to LCD mapping

# Change this table to match the BGM GPIO

# numbers to your display wiring

LCD_RS = 7

LCD_E  = 8

LCD_D4 = 25

LCD_D5 = 24

LCD_D6 = 23

LCD_D7 = 14

LED_ON = 15



# Define some device constants

LCD_WIDTH = 20    # Maximum characters per line

LCD_CHR = True

LCD_CMD = False



LCD_LINE_1 = 0x80 # LCD RAM address for the 1st line

LCD_LINE_2 = 0xC0 # LCD RAM address for the 2nd line

LCD_LINE_3 = 0x94 # LCD RAM address for the 3rd line

LCD_LINE_4 = 0xD4 # LCD RAM address for the 4th line



# Timing constants

E_PULSE = 0.0005

E_DELAY = 0.0005



# Scrolling constants

ST_DELAY = 1.5     # Delay before scrolling first line

SF_DELAY = .5      # Delay before scrolling second and third line

SC_DELAY = .25     # Delay between scrolling characters

SC_COUNT = 2       # Number of characters to scroll at one time

SC_REPEAT = True   # Continous scrolling switch

SR_DELAY = 10      # Delay before repeating the scrolling

VD_DISPLAY = True  # Volume display switch

VD_DELAY = 2.5     # Number of seconds to display volume change



# Cool our jets

time.sleep(15)



# currentsont.txt timestamp

csts = os.stat("/var/local/www/currentsong.txt").st_mtime

ivol = 0



def main():



  GPIO.setmode(GPIO.BCM)       # Use BCM GPIO numbers

  GPIO.setup(LCD_E, GPIO.OUT)  # E

  GPIO.setup(LCD_RS, GPIO.OUT) # RS

  GPIO.setup(LCD_D4, GPIO.OUT) # DB4

  GPIO.setup(LCD_D5, GPIO.OUT) # DB5

  GPIO.setup(LCD_D6, GPIO.OUT) # DB6

  GPIO.setup(LCD_D7, GPIO.OUT) # DB7

  GPIO.setup(LED_ON, GPIO.OUT) # Backlight enable



  # Initialise display

  splash_screen()

  lcd_backlight(False)

  while True:

    global csts, ivol

    # Has currentsong.txt changed?

    if (csts <> os.stat("/var/local/www/currentsong.txt").st_mtime):

      csts = os.stat("/var/local/www/currentsong.txt").st_mtime



      try:

        # Read the currentsong.txt file and format the diplay lines

        with open("/var/local/www/currentsong.txt","r") as currentsong:

          lines = currentsong.readlines()



          a,artist = lines[1].split("=")

          a,album = lines[2].split("=")

          a,title = lines[3].split("=")

          a,year = lines[6].split("=")

          a,encoded = lines[8].split("=")

          a,bitrate = lines[9].split("=")

          a,volume = lines[10].split("=")

          a,mute = lines[11].split("=")

          a,status = lines[12].split("=")



          # Remove white space

          artist = artist.strip()

          album = album.strip()

          title = title.strip()

          year = year.strip()

          encoded = encoded.strip()

          bitrate = bitrate.strip()

          volume = volume.strip()

          mute = mute.strip()

          status = status.strip()



          # Remove accented characters for LCD display

          artist = remove_accent(artist)

          album = remove_accent(album)

          title = remove_accent(title)



          # Flip bit depth and sample rate

          if ("/" in encoded):

            encoded_only = encoded.split(" ",1)

            bitdepth,samplerate = encoded_only[0].split("/")

            encoded = "%s-%s" % (samplerate, bitdepth)



          # Build the display lines

          if status == "stop":

            line1 = " moOde Audio Player"

            line2 = "We are done for now!"

            line3 = ""

            line4 = "  <== Stopped ==>"

        lcd_backlight(False)

          else:

            if artist == "Radio station":

          lcd_backlight(True)

              line1 = artist

              line2 = album

              if (title[:5] == "http:"):

                line3 = "Internet stream"

              else:

                line3 = title

            else:

          lcd_backlight(True)

              line1 = artist

              line2 = title

              line3 = album

            if status == "pause":

              line4 = "   <== Paused ==>"

          lcd_backlight(False)

            elif VD_DISPLAY:

              if mute == "1":

                ivol = -1

                line4 = "   <== Muted ==>"

                lcd_init()

              else:

                if ivol == volume:

                  line4 = "%s | %s" % (encoded, bitrate)

                else:

                  ivol = volume

                  line4 = "%s %s%s" % (" <== Volume", volume, "% ==>")

            else: 

              line4 = "%s | %s" % (encoded, bitrate)



          # Send the lines to the display

          lcd_string(line1,LCD_LINE_1,1)

          lcd_string(line2,LCD_LINE_2,1)

          lcd_string(line3,LCD_LINE_3,1)

          lcd_string(line4,LCD_LINE_4,1)



          # Close currentsong.txt

          currentsong.close()



          # Check if we need to display volume change

          if ("Volume" in line4 and VD_DISPLAY):

            sleep_for(VD_DELAY)

            csts = -1



          # Check if we need to scroll

          if (status == "play" and SC_REPEAT):

            rc = 0

            while rc>= 0:

          rc = check_scrolling(line1, line2, line3, csts)

          elif (status == "play"):

        check_scrolling(line1, line2, line3, csts)



      except Exception:

        pass



    else:

      sleep_for(.3)



def splash_screen():

  # Splash screen text

  lcd_init()

  line1 = "Welcome to the"

  line2 = "moOde Audio Player"

  line3 = "--------------------"

  line4 = "Enjoy the Music!"



  # Display the splash screen

  lcd_string(line1,LCD_LINE_1,2)

  lcd_string(line2,LCD_LINE_2,2)

  lcd_string(line3,LCD_LINE_3,2)

  lcd_string(line4,LCD_LINE_4,2)



def remove_accent(text):

  # Remove Accents

  text = text.replace("à", "a")

  text = text.replace("á", "a")

  text = text.replace("â", "a")

  text = text.replace("ã", "a")

  text = text.replace("ä", "a")

  text = text.replace("è", "e")

  text = text.replace("é", "e")

  text = text.replace("ê", "e")

  text = text.replace("ë", "e")

  text = text.replace("ì", "i")

  text = text.replace("í", "i")

  text = text.replace("î", "i")

  text = text.replace("ï", "i")

  text = text.replace("ñ", "n")

  text = text.replace("ò", "o")

  text = text.replace("ó", "o")

  text = text.replace("ô", "o")

  text = text.replace("õ", "o")

  text = text.replace("ö", "o")

  text = text.replace("ù", "u")

  text = text.replace("ú", "u")

  text = text.replace("û", "u")

  text = text.replace("ü", "u")

  text = text.replace("ý", "y")

  text = text.replace("ÿ", "y")

  text = text.replace("ç", "c")

  return text



def check_scrolling(line1, line2, line3, csts):

  # Check if display line needs to be scrolled

            S_DELAY = True

            if (len(line1) > LCD_WIDTH):

              S_DELAY = False

              time.sleep(ST_DELAY)

              # Scroll Line 1

              rc = scroll_line(line1, LCD_LINE_1, csts)

              if rc < 0:

                return rc



            if (len(line2) > LCD_WIDTH):

              if S_DELAY:

                S_DELAY = False

                time.sleep(ST_DELAY)

              else:

                time.sleep(SF_DELAY)

              # Scroll Line 2

              rc = scroll_line(line2, LCD_LINE_2, csts)

              if rc < 0:

                return rc



            if (len(line3) > LCD_WIDTH):

              if S_DELAY:

                S_DELAY = False

                time.sleep(ST_DELAY)

              else:

                time.sleep(SF_DELAY)

              # Scroll Line 3

              rc = scroll_line(line3, LCD_LINE_3, csts)

              if rc < 0:

                return rc



            if (SC_REPEAT and not S_DELAY):

              rc = sleep_for(SR_DELAY)

              return rc

            else:

              rc = sleep_for(.3)

              return rc



def scroll_line(text, line, csts):

  # Scroll display line

  if (len(text) % SC_COUNT == 0):

    line_length = len(text) + 1

  else:

    line_length = len(text) + SC_COUNT

  for num in xrange(SC_COUNT,line_length,SC_COUNT):

    if (csts <> os.stat("/var/local/www/currentsong.txt").st_mtime):

      return -1

    scrollpart = text[num:num + 20]

    lcd_string(scrollpart,line,1)

    if scrollpart == "":

      time.sleep(SF_DELAY)

    else:

      time.sleep(SC_DELAY)

  lcd_string(text,line,1)

  return 0



def sleep_for(count):

  # Sleep for count seconds and check for exit every .1 seconds

  count = int((count * 10)//1)

  for num in xrange(1,count,1):

    if (csts <> os.stat("/var/local/www/currentsong.txt").st_mtime):

      return -1

    else:

      time.sleep(.1)

  return 0



def lcd_init():

  # Initialise display

  lcd_byte(0x33,LCD_CMD) # 110011 Initialise

  lcd_byte(0x32,LCD_CMD) # 110010 Initialise

  lcd_byte(0x06,LCD_CMD) # 000110 Cursor move direction

  lcd_byte(0x0C,LCD_CMD) # 001100 Display On,Cursor Off, Blink Off

  lcd_byte(0x28,LCD_CMD) # 101000 Data length, number of lines, font size

  lcd_byte(0x01,LCD_CMD) # 000001 Clear display

  time.sleep(E_DELAY)



def lcd_byte(bits, mode):

  # Send byte to data pins

  # bits = data

  # mode = True  for character

  #        False for command



  GPIO.output(LCD_RS, mode) # RS



  # High bits

  GPIO.output(LCD_D4, False)

  GPIO.output(LCD_D5, False)

  GPIO.output(LCD_D6, False)

  GPIO.output(LCD_D7, False)

  if bits&0x10==0x10:

    GPIO.output(LCD_D4, True)

  if bits&0x20==0x20:

    GPIO.output(LCD_D5, True)

  if bits&0x40==0x40:

    GPIO.output(LCD_D6, True)

  if bits&0x80==0x80:

    GPIO.output(LCD_D7, True)



 # Toggle 'Enable' pin

  lcd_toggle_enable()



  # Low bits

  GPIO.output(LCD_D4, False)

  GPIO.output(LCD_D5, False)

  GPIO.output(LCD_D6, False)

  GPIO.output(LCD_D7, False)

  if bits&0x01==0x01:

    GPIO.output(LCD_D4, True)

  if bits&0x02==0x02:

    GPIO.output(LCD_D5, True)

  if bits&0x04==0x04:

    GPIO.output(LCD_D6, True)

  if bits&0x08==0x08:

    GPIO.output(LCD_D7, True)



  # Toggle 'Enable' pin

  lcd_toggle_enable()



def lcd_toggle_enable():

  # Toggle enable

  time.sleep(E_DELAY)

  GPIO.output(LCD_E, True)

  time.sleep(E_PULSE)

  GPIO.output(LCD_E, False)

  time.sleep(E_DELAY)



def lcd_string(message,line,style):

  # Send string to display

  # style=1 Left justified

  # style=2 Centred

  # style=3 Right justified



  if style==1:

    message = message.ljust(LCD_WIDTH," ")

  elif style==2:

    message = message.center(LCD_WIDTH," ")

  elif style==3:

    message = message.rjust(LCD_WIDTH," ")



  lcd_byte(line, LCD_CMD)



  for i in range(LCD_WIDTH):

    lcd_byte(ord(message[i]),LCD_CHR)



def lcd_backlight(flag):

  # Toggle backlight on-off-on

  GPIO.output(LED_ON, flag)



if __name__ == '__main__':

 

  try:

    main()

  except KeyboardInterrupt:

    pass

  finally:

    lcd_init()

    GPIO.cleanup()