iPod-style Spotify track info display (or clock when no track is playing) using 16x2 I2C LCD (Python 2 only)

DisplaySong.py

# Requires smbus: sudo apt install python-smbus
import I2C_LCD_driver
import time
import json
import httplib
import io
import os
from sys import exit

# Add the refresh key here (https://bit.ly/2DM1oRZ)
refresh_key = ""
# Specifies the number of minutes the clock will appear after (0 to turn off)
clock_appear_frequency = 3

lcd = I2C_LCD_driver.lcd(0x27)
top_offset = 0
bottom_offset = 0
last_track = None
authkey = ""
expire_time = 0
need_clock = False
timeout = 0

if refresh_key == "":
    lcd.lcd_display_string(" Please add key ", 1)
    lcd.lcd_display_string(" to script file ", 2)
    time.sleep(3)
    lcd.lcd_display_string("https://bit.ly/ ", 1)
    lcd.lcd_display_string("2DM1oRZ         ", 2)
    while True:
        time.sleep(100)

def getAuthKey():
    global authkey
    global expire_time
    tokreq = httplib.HTTPConnection("cppconsole.bruienne.com", timeout=1)
    tokres = None
    try:
        tokreq.request("GET", "/spotipi/get_token.php?token=" + refresh_key)
        tokres = tokreq.getresponse()
    except (socket.timeout, ssl.SSLError):
        lcd.lcd_display_string("  Failed to get ", 1)
        lcd.lcd_display_string("   access key   ", 2)
        print("Timeout")
        time.sleep(5)
        authkey = ""
        return
    if tokres.status != 200:
        lcd.lcd_display_string("  Failed to get ", 1)
        lcd.lcd_display_string("   access key   ", 2)
        print("HTTP " + str(tokres.status))
        time.sleep(5)
        authkey = ""
        return

    tokresbody = tokres.read()
    if tokresbody == "":
        lcd.lcd_display_string("  Failed to get ", 1)
        lcd.lcd_display_string("   access key   ", 2)
        print("Empty body")
        time.sleep(5)
        authkey = ""
        return
    tokbody = json.loads(tokresbody)
    authkey = tokbody["token_type"] + " " + tokbody["access_token"]
    expire_time = time.time() + tokbody["expires_in"]

def addWithMax(add1, add2, max, min = 0):
    if add1 + add2 >= max:
        return ((add1 + add2) - max * int((add1 + add2) / max)) + min
    else:
        return add1 + add2

def substrWrap(string, start, length):
    retval = ""
    for i in range(0, length):
        retval += string[addWithMax(start, i, len(string))]
    return retval

def getTrackData():
    req = httplib.HTTPSConnection("api.spotify.com")
    req.request("GET", "/v1/me/player/currently-playing", None, {"Authorization": authkey})
    res = req.getresponse()
    if res.status != 200:
        print("Got code " + str(res.status))
        return None
    
    body = json.loads(res.read())
    if body["currently_playing_type"] == "ad":
        return {"album": "", "artist": "", "track": "Advertisement"}
    if not body["is_playing"] or body["item"] == None:
        return None

    artists = ""
    for a in body["item"]["artists"]:
        if artists != "":
            artists += ", "
        artists += a["name"]
    return {
        "album": body["item"]["album"]["name"],
        "artist": artists,
        "track": body["item"]["name"]
        }

print("Getting key...")
getAuthKey()
lcd.lcd_clear()

while True:
    if expire_time <= time.time() or authkey == "":
        end_timee = time.time() + 5
        while end_timee > time.time():
            lcd.lcd_display_string("    %s    " %time.strftime("%H:%M:%S"), 1)
            lcd.lcd_display_string("   %s   " %time.strftime("%m/%d/%Y"), 2)
            time.sleep(.05)
        top_offset = -4
        bottom_offset = -4
        getAuthKey()
    elif int(time.time() % (clock_appear_frequency * 60)) == 0 and clock_appear_frequency > 0:
        need_clock = True
    if need_clock and (top_offset == 0 or bottom_offset == 0):
        end_time = time.time() + 5
        lcd.lcd_clear()
        while end_time > time.time():
            lcd.lcd_display_string("    %s    " %time.strftime("%H:%M:%S"), 1)
            lcd.lcd_display_string("   %s   " %time.strftime("%m/%d/%Y"), 2)
            time.sleep(.05)
        top_offset = -4
        bottom_offset = -4
        lcd.lcd_clear()
        need_clock = False
    track = getTrackData()
    if track == {}:
        track = last_track
    print(track)
    if track == None:
        lcd.lcd_display_string("    %s    " %time.strftime("%H:%M:%S"), 1)
        lcd.lcd_display_string("   %s   " %time.strftime("%m/%d/%Y"), 2)
        top_offset = -4
        bottom_offset = -4
        need_clock = False
        last_track = None
        time.sleep(0.25)
        continue
    if last_track != track:
        top_offset = -4
        bottom_offset = -4
    top_line = track["track"]
    bottom_line = track["artist"] + " -- " + track["album"]
    if len(top_line) > 16 and len(bottom_line) > 16:
        if len(top_line) > len(bottom_line):
            bottom_line = bottom_line.ljust(len(top_line))
        elif len(bottom_line) > len(top_line):
            top_line = top_line.ljust(len(bottom_line))
    top_line_orig = top_line
    bottom_line_orig = bottom_line
    top_pos = top_offset
    if top_pos < 0:
        top_pos = 0
    bottom_pos = bottom_offset
    if bottom_pos < 0:
         bottom_pos = 0
    if len(top_line) < 16:
        top_line = top_line.center(16)
    elif len(top_line) > 16:
        top_line = substrWrap(top_line + "    ", top_pos, 16)
    if len(bottom_line) < 16:
        bottom_line = bottom_line.center(16)
    elif len(bottom_line) > 16:
        bottom_line = substrWrap(bottom_line + "    ", bottom_pos, 16)
    lcd.lcd_display_string(top_line, 1)
    lcd.lcd_display_string(bottom_line, 2)
    top_offset = addWithMax(top_offset, 1, len(top_line_orig) + 4, -4)
    bottom_offset = addWithMax(bottom_offset, 1, len(bottom_line_orig) + 4, -4)
    time.sleep(.25)
    last_track = track

I2C_LCD_driver.py

# -*- 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

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, addr):
      self.lcd_device = i2c_device(addr)

      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)         
         

hi. it is awesome your code. i adapted to an LCD 20x4 (getting info about temp CPU and ip, adr. etc) but i get an error when i run the script about ,, clock_appear_frequency " line 117 . Python say that it not was definite . If i comment line 117 the script is running whiteout errors.
I am a beginner in python language.

@cosminiq :

hi. it is awesome your code. i adapted to an LCD 20x4 (getting info about temp CPU and ip, adr. etc) but i get an error when i run the script about ,, clock_appear_frequency " line 117 . Python say that it not was definite . If i comment line 117 the script is running whiteout errors.

Oops, I must have accidentally erased that line. I've updated the script to fix it. Basically, you need to add this to the top of the script below the refresh_key (line 12):

# Specifies the number of minutes the clock will appear after (0 to turn off)
clock_appear_frequency = 3

That should fix your problem, and will properly show the clock while playing music.

i implement de line, it runs nicely. i am verity impressed by your programming skills.
In past i used jSon lib, on Arduino IDE for a meteo station, but was a liitle harder on a microcontroller like (esp 32). On raspberry Pi is more easy.

thanks for you fast reply.

my respects!