qbee-gpio

A python script to control an LCD and amplifier relay for use in an AirPlay and/or Spotify Connect Raspberry Pi server.

• Detect sound ouput and turn on the amplifier power supply.
• Get the track information and display it on an LCD.
• Auto turn off amplifier power supply and/or shutdown after set period of inactivity.

Installation

sudo python -m pip install qbee-gpio

For first time usage:

qbee --init-config

then change what you need in ~/.qbee.yaml.

Usage

qbee

Pass a -v flag for verbose logging.

Detailed setup

Qbee

For starting up automatically, create /etc/systemd/system/qbee.service file with (adjust users/paths):

[Unit]
Description=Qbee
After=network-online.target
StartLimitIntervalSec=500
StartLimitBurst=5

[Service]
User=qbee
Group=qbee
ExecStart=/usr/local/bin/qbee
Restart=on-failure
RestartSec=5s

[Install]
WantedBy=multi-user.target

Enable to run on boot: sudo systemctl enable qbee --now.

Optionally, specify a CONFIG env variable when running the script: CONFIG="/etc/qbee.yaml" ~/.local/bin/qbee .... The default config will be located at ~/.qbee.yaml.

See all config options

Setting up shairport-sync

You can follow instructions here. Here is what I used.

Install required packages:

sudo apt install --no-install-recommends build-essential git autoconf automake libtool \
    libpopt-dev libconfig-dev libasound2-dev avahi-daemon libavahi-client-dev libssl-dev libsoxr-dev

Install shairport-sync:

git clone https://github.com/mikebrady/shairport-sync.git
cd shairport-sync
autoreconf -fi
./configure --sysconfdir=/etc --with-alsa --with-soxr --with-avahi --with-ssl=openssl --with-systemd --with-metadata
make
make install
cd ../ && rm -rf shairport-sync

Edit /etc/shairport-sync.conf file, uncomment the metadata block to enable:

metadata =
{
        enabled = "yes";
        include_cover_art = "no";
        pipe_name = "/tmp/shairport-sync-metadata";
        pipe_timeout = 5000;
};

Enable to run on boot: sudo systemctl enable shairport-sync --now.

Setting up Librespot

If Raspotify is available on your system, use it, otherwise, you will need to compile librespot.

For starting up automatically, create /lib/systemd/system/librespot.service file with (adjust users/paths):

[Unit]
Description=Librespot
After=sound.target
Requires=avahi-daemon.service
After=avahi-daemon.service
Wants=network-online.target
After=network.target network-online.target

[Service]
User=qbee
Group=qbee
EnvironmentFile=/etc/librespot.env
ExecStart=/usr/bin/librespot
Restart=on-failure
RestartSec=5s

[Install]
WantedBy=multi-user.target

The conf /etc/librespot.env should look like:

LIBRESPOT_NAME="Qbee"

LIBRESPOT_QUIET=

LIBRESPOT_ENABLE_VOLUME_NORMALISATION=
LIBRESPOT_BITRATE="320"
LIBRESPOT_BACKEND="alsa"
LIBRESPOT_INITIAL_VOLUME="40"

LIBRESPOT_ONEVENT="/usr/local/bin/librespot-pipe.sh"

QBEE_LIBRESPOT_METADATA_PIPE="/tmp/librespot-metadata"

You will also need to set up the script to pipe events to Qbee in /usr/local/bin/librespot-pipe.sh and make it executable:

#!/usr/bin/bash

# Expose track_changed librespot events in a named pipe.

# Only expose track changed events.
if [ "$PLAYER_EVENT" != 'track_changed' ]; then
  exit 0
fi
# Need a named pipe.
if [ "$QBEE_LIBRESPOT_METADATA_PIPE" == '' ]; then
  exit 0
fi
# It must already be opened for reading.
if ! [ -p "$QBEE_LIBRESPOT_METADATA_PIPE" ] ; then
  exit 0
fi
artist=$(printf '%s' "$ARTISTS" | base64)
album=$(printf '%s' "$ALBUM" | base64)
title=$(printf '%s' "$NAME" | base64)
printf 'artist:%s,album:%s,title:%s\t' "$artist" "$album" "$title" > "$QBEE_LIBRESPOT_METADATA_PIPE"

Setting up Hifiberry DAC

Edit /boot/config.txt to add:

dtparam=audio=on
dtoverlay=hifiberry-dac

To disable the built-in sound card, edit /etc/modprobe.d/raspi-blacklist.conf to add:

blacklist snd_bcm2835

Edit /etc/asound.conf to set the default sound card for alsa, add:

defaults.pcm.card 0
defaults.ctl.card 0

Disable Pi GPU

This should help give more power to the CPU, useful for older Pis. Edit /boot/config.txt and add:

gpu_mem=16
disable_l2cache=0  # For pi 1 only
gpu_freq=250

Full circuit diagram

The relay turns on the 24 VDC power supply, which powers the amplifier, the LCD backlight and a green status LED.