piplayer/code/piplayer3.py

# piplayer3 - AudioSaucer
# http://www.tilman.de/piplayer3
import RPi.GPIO as GPIO
import logging
import time
import subprocess
import select  # for polling zbarcam, see http://stackoverflow.com/a/10759061/3761783
import os
import requests
import urllib

logging.basicConfig(level=logging.INFO, format='%(asctime)s %(levelname)s - %(message)s')
logging.info('Initializing')

# Configuration
MUSIC_BASE_DIRECTORY = "/media/share/Kinder/"
SOUND_SCANNING = "file:///home/pi/sounds/scanning.mp3"
SOUND_OK = "file:///home/pi/sounds/ok.mp3"
SOUND_SCAN_FAIL = "file:///home/pi/sounds/fail.mp3"
SOUND_PLAYBACK_ERROR = "file:///home/pi/sounds/error.mp3"
QR_SCANNER_TIMEOUT = 3

MOPIDY_RPC_URL = 'http://127.0.0.1:6680/mopidy/rpc'
MUSIC_EXTENSIONS = ('.aac', '.ac3', '.aiff', '.amr', '.au', '.flac', '.m4a', '.mid', '.mka', '.mp3', '.ogg', '.ra', '.voc', '.wav', '.wma')

# photo sensor on PIN 17
PIN_SENSOR = 17

# IR LED on PIN 22
PIN_IR_LED = 22

# LED on PIN 27
PIN_LED = 27

# Buttons on PINs 9, 10 and 11
PIN_PREV = 9
PIN_PLAY = 10
PIN_NEXT = 11


GPIO.setmode(GPIO.BCM)

GPIO.setup(PIN_SENSOR, GPIO.IN)

GPIO.setup(PIN_IR_LED, GPIO.OUT)
GPIO.output(PIN_IR_LED, GPIO.LOW)

GPIO.setup(PIN_LED, GPIO.OUT)
GPIO.output(PIN_LED, GPIO.LOW)

GPIO.setup(PIN_PREV, GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.setup(PIN_PLAY, GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.setup(PIN_NEXT, GPIO.IN, pull_up_down=GPIO.PUD_UP)



def call(method, params=None):
    if (params is None):
        json = '{"jsonrpc": "2.0", "id": 1, "method": "' + method + '"}'
    else:
        json = '{"jsonrpc": "2.0", "id": 1, "method": "' + method + '" , "params": ' + params + '}'
    
    response = requests.post(MOPIDY_RPC_URL, data=json)
    logging.debug(response.text)
    return response

def add_uri(filename):
    logging.debug('Adding ' + filename)
    call('core.tracklist.add', '{"uri": "' + filename + '"}')

def play_sound(filename):
    call('core.tracklist.clear')
    logging.debug('Cleared tracklist, now playing ' + filename)
    add_uri(filename)
    call('core.playback.play')

def list_files(dir):
    r = []
    for path, dirs, files in os.walk(dir):
        dirs.sort()
        files.sort()
        for name in files:
            r.append(os.path.join(path, name))
    return r



def btn1_callback(channel):
    logging.debug("PREV")
    json = call('core.playback.get_time_position').json()
    if (json['result'] < 4000):
        call('core.playback.previous')
    else:
        call('core.playback.seek', '{ "time_position": 0 }')
       
def btn2_callback(channel):
    logging.debug("PLAY/PAUSE")
    json = call('core.playback.get_state').json()
    if (json['result'] == 'playing'):
        call('core.playback.pause')
    else:
        call('core.playback.play')

def btn3_callback(channel):
    logging.debug("NEXT")
    call('core.playback.next')


GPIO.add_event_detect(PIN_PREV, GPIO.FALLING, callback=btn1_callback, bouncetime=400)
GPIO.add_event_detect(PIN_PLAY, GPIO.FALLING, callback=btn2_callback, bouncetime=400)
GPIO.add_event_detect(PIN_NEXT, GPIO.FALLING, callback=btn3_callback, bouncetime=400)


try:
    # FIXME turn this into a proper service and wait for the network interface (and mopidy)
    # https://www.dexterindustries.com/howto/run-a-program-on-your-raspberry-pi-at-startup/#systemd
    time.sleep(20)
    
    play_sound(SOUND_OK)
    
    while True:
        logging.debug('Wait for photo sensor')
        GPIO.wait_for_edge(PIN_SENSOR, GPIO.RISING)
        
        logging.debug('Photo sensor active, activating light and camera')
        play_sound(SOUND_SCANNING)
        
        # turn LED on
        GPIO.output(PIN_LED, GPIO.HIGH)
        
        # scan QR code
        zbarcam = subprocess.Popen(['zbarcam', '--quiet', '--nodisplay', '--raw', '-Sdisable', '-Sqrcode.enable', '--prescale=320x240', '/dev/video0'], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        
        poll_obj = select.poll()
        poll_obj.register(zbarcam.stdout, select.POLLIN)
        
        # wait for scan result (or timeout)
        start_time = time.time()
        poll_result = False
        while ((time.time() - start_time) < QR_SCANNER_TIMEOUT and (not poll_result)):
            poll_result = poll_obj.poll(100)

        if (poll_result):
            
            try:
                # play confirmation sound
                play_sound(SOUND_OK)
                
                call('core.tracklist.clear')
                logging.debug("Stopped")
                
                qr_code = zbarcam.stdout.readline().rstrip()
                qr_code = qr_code.decode("utf-8") # python3
                logging.info("QR Code: " + qr_code)
                
                if (not (qr_code.startswith("http://") or qr_code.startswith("spotify:"))):
                    # create full path
                    full_path = MUSIC_BASE_DIRECTORY + qr_code
                    
                    if (not os.path.isfile(full_path)):
                        logging.debug("Not a file, recursively add all audio files in directory")
                        filenames = list_files(full_path)
                        playback_started = False
                        for filename in filenames:
                            if filename.lower().endswith(MUSIC_EXTENSIONS):
                                add_uri("file://" + urllib.parse.quote(filename))
                                if (not playback_started):
                                    call('core.playback.play')
                                    playback_started = True
                                    
                        
                    else:
                        logging.debug("It's a file")
                        add_uri("file://" + urllib.parse.quote(full_path))
                        call('core.playback.play')
                    
                else:
                    logging.debug("URL, open directly")
                    add_uri(qr_code)
                    call('core.playback.play')
                
            except subprocess.CalledProcessError as e:
                logging.error("Error starting playback, mocp returned {}".format(e.returncode))
                logging.error(e.output)
                play_sound(SOUND_PLAYBACK_ERROR)
            except FileNotFoundError as e:
                logging.error("Could not open directory {}".format(directory))
                play_sound(SOUND_PLAYBACK_ERROR)

        else:
            logging.warning('Timeout on zbarcam')
            play_sound(SOUND_SCAN_FAIL)
            
        zbarcam.terminate()
        
        # LED off
        GPIO.output(PIN_LED, GPIO.LOW)

        # wait until sensor is not blocked anymore
        if (GPIO.input(PIN_SENSOR) == GPIO.HIGH):
            GPIO.wait_for_edge(PIN_SENSOR, GPIO.FALLING)
            time.sleep(1)

        
# Exit when Ctrl-C is pressed
except KeyboardInterrupt:
    logging.info('Shutdown')
    
finally:
    logging.info('Reset GPIO configuration and close')
    GPIO.cleanup()