Raspberry Pi Internet Radio

#!/usr/bin/python
#
# Script for Raspberry Pi Internet Radio
#
# Updates   :   Peter Foster (2013/02/11)
# Email :       [email protected]
# Notes:
#      - fixed a few bugs
#      - allowed quicker breakout from scrolling after channel change
#
# Updates   :   James Bos (2013/01/18)
# Email :   [email protected]
#
#       Notes:
#   * Changed for 16x2 LCD
#       * Scrolling Song name (not the best code since my python is quire poor but it works!)
#       * Display Station Name on 2nd line of LCD
#       * Added 3rd button to show IP address and Uptime
#       * Silly starting animation!
#
#       TO-DO:
#       * Learn some better code practices so for loop for scrolling LCD doesn't
#           affect button pushes (need to hold your finger on button for sleeptime)
#       * Volume control!!!
#       * Volume control display!!!!!!!
#
# Original Author: Kyle Prier
# Site: http://www.youtube.com/meistervision
#
# Original LCD author : Matt Hawkins
# Site   : http://www.raspberrypi-spy.co.uk/
#
# Date   : 10/01/2012
#

# 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! We do not want the LCD to send anything to the Pi @ 5v
# 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 (Red)
# 17: LCD Backlight GND (Green)
# 18: LCD Backlight GND (Blue)

#import
import RPi.GPIO as GPIO
import time
import os

# Define GPIO to LCD mapping

LCD_RS = 7
LCD_E  = 8
LCD_D4 = 25
LCD_D5 = 24
LCD_D6 = 23
LCD_D7 = 18

# Defomte GPIO for Radio Controls
NEXT = 4
PREV = 17
INFO = 15

# Define some device constants
LCD_WIDTH = 16    # Maximum characters per line (change to 20 for 20x4)
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 = 0.00005
E_DELAY = 0.00005

def main():
    # Main program block
    GPIO.setwarnings(False)
    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(NEXT, GPIO.IN) # Next Channel button
    GPIO.setup(PREV, GPIO.IN) # Previous Channel button
    #GPIO.setup(INFO, GPIO.IN) # INFO Button

    # Calls the start up animation function
    start_up_anime()

    # Start playing mpc straight away
    os.system("mpc play")

    # Run our core function (scrolling and button code)
    while True:
        core()

# Define our core program
def core():
    # Declare "f" as our mpc current song title var
    f=os.popen("mpc -f %title% current")
    # Declare "s" as our station name var
    s=os.popen("mpc -f %name% current").read()
    s=s.strip()
    # Declare an empty var for station (for use further down)
    station = ""

    # Declare our default sleeptime for how quickly our text scrolls
    # This also affects how quickly our button presses are picked up (not good :()
    sleeptime=0.3

    # Start reading our lines from out "f" var in order to break it down and scroll
    for i in f.readlines():
                i=i.strip()
        station += i # include station in our iterator (i)
        str_pad = " " * 16 #  same as 16 spaces
        station = str_pad + station # combine both together

        # iterates of the length of our station var (16)
        for i in range (0, len(station)):
            lcd_byte(LCD_LINE_1, LCD_CMD) # set the marker to the first line of our LCD
            lcd_text = station[i:(i+16)] # var for each line of text for each position as it iterates over for loop
            lcd_string(lcd_text,1) # send our text to the LCD
            lcd_byte(LCD_LINE_2, LCD_CMD) # set the marker to the 2nd line of our LCD
            lcd_string(s,2) # display our station (this one doesn't scroll since 2 scrolling at once is headache worthy!)

            # When our GPIO is high (button is pressed) calls mpc and moves to next track
            if ( GPIO.input(NEXT) == False):
                os.system("mpc next") # call mpc to move on to next track
                time.sleep(0.5) # sleep for half a second and give her some time!
                os.system("mpc play") # call mpc to play

                # (sleeptime=0) changes sleep time to 0, this will cause previous track info on
                # the LCD to quickly move across the screen and move on to next track.
                # this isn't here for effect (since it kinda looks cool I know:)) but it is here
                # so the the new track info is shown more quickly (so the for loop completes more quickly
                # and moves on to pushing the new info on the screen)
                sleeptime=0
                time.sleep(1)

            # Same as above but for previous track,
            if ( GPIO.input(PREV) == False):
                os.system("mpc prev")
                time.sleep(0.5)
                os.system("mpc play")
                sleeptime=0
                                time.sleep(1)

            # This calls the uptime and ip for diognostic junk (eg: oops, whats the IP again?? :))
            #if ( GPIO.input(INFO) == True):
            #   osIp=os.popen("ip addr | awk 'NR==6'").read()
            #   osIp=osIp[9:24]
            #   osUptime=os.popen("uptime | awk -F'[,]' '{print $1 $2}'").read()
            #   osUptime=osUptime[10:]
            #   lcd_byte(LCD_LINE_1, LCD_CMD)
            #   lcd_string(osUptime,1)
            #   lcd_byte(LCD_LINE_2, LCD_CMD)
            #   lcd_string(osIp,2)
            #   time.sleep(5)

            # sleep time for iterating over the loop
            if(sleeptime==0):
                          break
                        time.sleep(sleeptime)

def lcd_init():
  # Initialise display
  lcd_byte(0x33,LCD_CMD)
  lcd_byte(0x32,LCD_CMD)
  lcd_byte(0x28,LCD_CMD)
  lcd_byte(0x0C,LCD_CMD)
  lcd_byte(0x06,LCD_CMD)
  lcd_byte(0x01,LCD_CMD)

def lcd_string(message,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," ")

  for i in range(LCD_WIDTH):
    lcd_byte(ord(message[i]),LCD_CHR)

def start_up_anime():
    # Initialise display
    lcd_init()
    # Send some test
    lcd_byte(LCD_LINE_1, LCD_CMD)
    lcd_string("Raspberry Pi",2)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("      RADIO     ",1)
    time.sleep(0.1)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("    R A D I O   ",1)
    time.sleep(0.1)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("  R  A  D  I  O ",1)
    time.sleep(0.1)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("R   A   D   I  O",1)
    time.sleep(0.1)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("R    A    D    I",1)
    time.sleep(0.1)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("R     A     D   ",1)
    time.sleep(0.1)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("   R     A     D",1)
    time.sleep(0.1)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("    R     A     ",1)
    time.sleep(0.1)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("     R     A    ",1)
    time.sleep(0.1)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("      R     A   ",1)
    time.sleep(0.1)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("       R     A  ",1)
    time.sleep(0.1)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("        R     A ",1)
    time.sleep(0.1)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("         R     A",1)
    time.sleep(0.1)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("          R     ",1)
    time.sleep(0.1)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("           R    ",1)
    time.sleep(0.1)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("            R   ",1)
    time.sleep(0.1)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("             R  ",1)
    time.sleep(0.1)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("              R ",1)
    time.sleep(0.1)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("               R",1)
    time.sleep(0.1)
    lcd_byte(LCD_LINE_2, LCD_CMD)
    lcd_string("                ",1)
    time.sleep(.2)

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
  time.sleep(E_DELAY)
  GPIO.output(LCD_E, True)
  time.sleep(E_PULSE)
  GPIO.output(LCD_E, False)
  time.sleep(E_DELAY)

  # 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
  time.sleep(E_DELAY)
  GPIO.output(LCD_E, True)
  time.sleep(E_PULSE)
  GPIO.output(LCD_E, False)
  time.sleep(E_DELAY)


if __name__ == '__main__':
  main()