Connect Variable to use for GPIO signal?

[myichimoku]

Hi There!
Thanks for this great project. I have been using it for a couple of years now without any issues.
I would like to be able to use a variable to put on one of the GPIO pins to light-up a LED or a relay (TBD) upon (dis)connection.
I guess it exists as in the spotify app we see the connect icon turn green.
Any idea where I can find that and how to use it?
Thanks,
Oscar

[JasonLG1979]

What you're looking for is the --onevent librespot flag.

https://github.com/librespot-org/librespot/wiki/Options

librespot-org/librespot#185

https://github.com/librespot-org/librespot/blob/dev/src/player_event_handler.rs

[myichimoku]

Thanks! Sorry for the delay... Hope to get to it durng the weeks ahead...

[JasonLG1979]

Thanks! Sorry for the delay... Hope to get to it durng the weeks ahead...

Keep in mind that the onevent script will be executed with the same privileges as the service which are basically nothing and most of the file system is either read only or completely inaccessible to the Raspotify service. Putting fifo's under /var/run seems to work so I'd imagine that would be a good place to start. Otherwise if need be I can open a specific location like /var/run/raspotify for onevent scripts? I'd need to figure out where the most proper place would be according to convention and the LSB.

Again this is uncharted territory.

[JasonLG1979]

Speaking of fifo's, A not so elegant solution could be:

Program B creates and listens to /var/run/programB/fifo and does whatever you want to do.
onevent script writes to /var/run/programB/fifo.

[JasonLG1979]

Totally untested but based on player_event_handler.rs (the part of librespot that talks to the onevent scripts) a skeleton of a python onevent script might look something like this:

import os

if os.environ['PLAYER_EVENT'] == 'changed':
    old_track_id = os.environ['OLD_TRACK_ID']
    new_track_id = os.environ['TRACK_ID']
    # do stuff

elif os.environ['PLAYER_EVENT'] == 'started':
    track_id = os.environ['TRACK_ID']
    # do suff

elif os.environ['PLAYER_EVENT'] == 'stopped':
    track_id = os.environ['TRACK_ID']
    # do stuff
   
elif os.environ['PLAYER_EVENT'] == 'playing':
    track_id = os.environ['TRACK_ID']
    track_duration_ms = os.environ['DURATION_MS']
    track_position_ms = os.environ['POSITION_MS']
    # do stuff

elif os.environ['PLAYER_EVENT'] == 'paused':
    track_id = os.environ['TRACK_ID']
    track_duration_ms = os.environ['DURATION_MS']
    track_position_ms = os.environ['POSITION_MS']
    # do stuff

elif os.environ['PLAYER_EVENT'] == 'preloading':
    track_id = os.environ['TRACK_ID']
    # do stuff

elif os.environ['PLAYER_EVENT'] == 'volume_set':
    volume = os.environ['VOLUME']
    # do stuff

Also note that the script will be called in a non-blocking fashion.

[JasonLG1979]

Writing to a fifo might look something like this in Python3:

#!/usr/bin/python3
import os
import json

fifo_path = "./my_fifo"

try:
    os.mkfifo(fifo_path, 0o666)
except FileExistsError:
    # That's Ok...
    pass

except PermissionError as e:
    # You don't have permission to create a file in that location...
    print("PermissionError: {}".format(e))
    pass

except Exception as e:
    # Handle this...
    print(e)
    pass

json_dict = None

if os.getenv('PLAYER_EVENT') == 'changed':
    json_dict = {
        'event': os.getenv('PLAYER_EVENT'),
        'old_track_id': os.getenv('OLD_TRACK_ID') or '',
        'new_track_id': os.getenv('TRACK_ID') or ''
    }

elif os.getenv('PLAYER_EVENT') in ('started', 'stopped', 'preloading'):
    json_dict = {
        'event': os.getenv('PLAYER_EVENT'),
        'track_id': os.getenv('TRACK_ID') or ''
    }

elif os.getenv('PLAYER_EVENT') in ('playing', 'paused'):
    json_dict = {
        'event': os.getenv('PLAYER_EVENT'),
        'track_id': os.getenv('TRACK_ID') or '',
        'duration_ms': os.getenv('DURATION_MS') or '0',
        'position_ms': os.getenv('POSITION_MS') or '0'
    }

elif os.getenv('PLAYER_EVENT') == 'volume_set':
    json_dict = {
        'event': os.getenv('PLAYER_EVENT'),
        'volume': os.getenv('VOLUME') or '0'
    }

if json_dict:
   print(json_dict)
   with open(fifo_path, 'w') as f:
        try:
            json.dump(json_dict, f)
        except KeyboardInterrupt:
            pass
        except Exception as e:
            # Handle this...
            print(e)
            pass