Part 2

STEP by STEP GUIDE

INSTALL RASPBIAN (a debian wheezy distro for Raspberry PI)
Raspbian
Installer
Note: Follow the instructions carefully and test the set-up and make sure everything is running!

#########

INSTALL VNC (for maintanance / update and installing purposes)

I followed this
Note: Autostart VNC (more about this here: http://myraspberrypiexperience…..p-vnc.html) at each boot. If you don't want a graphical VNC connection, you can omit this step and use the SSH command line instead.

#########

ADJUSTMENTS & TWEAKS REQUIRED AT THIS STAGE

- Turn-off "blank monitor" property: If this is not done, your monitor will go blank for power saving purposes. We are running a 5W system on 4-wheels, so we are not worried about this at all. Let's turn the monitor on for ever (well, as long as you have the ignition on)

sudo nano /etc/kbd/config and enter the following values:

BLANK_TIME=0
POWERDOWN_TIME=0

Some body has claimed that this did not work. Therefore, in addition, I used this as well:

sudo nano /etc/lightdm/lightdm.conf


Look for [SeatDefault] and insert:
xserver-command=X -s 0 dpms


- Sound output via the USB sound card / DAC
Note: The analog onboard sound is bad and the output is weak. I did not try the digital HDMI-sound, since a DAC needed here as well to get the audio via 3.5mm aux plug for the car stereos. If any body has tested this, would love to hear the results, as well. Once again, we are in a car, so probably we do not have a digital sound input port for the car stereo. At home, probably, I would go with HDMI-sound and by-pass it via my stereo amplifier which has a decent DAC.

First install alsa-util and plug-ins if not already installed

sudo apt-get alsa-util alsa-plugins

Check if your usb sound card is recognised by the system and note the card and the device number – write it down.

aplay -l

Your hardware will be presented in the list. Note down the numbers. Mine reads:

card 0: Device [C-Media USB Audio Device], device 0: USB Audio [USB Audio]
card 1: ALSA [bcm2835 ALSA], device 0: bcm2835 ALSA [bcm2835 ALSA]

So, the USB-sound device is "hw:0,0" and the onboard analog device "hw:1,0"

Now change the default output from snd-bcm2835 to your sound card using the alsamixer
alsamixer

Make this the default sound device after a reboot.
sudo nano /etc/modprobe.d/alsa-base.conf

Comment-out the following line from "options snd-usb-audio index=-2" to:
#options snd-usb-audio index=-2

Next, modify the following file in order to use the USB-sound instead of analog output (this file will be disabled when you start using MPD later – but at this stage it is still needed)

sudo nano /etc/.asound.conf

Comment out all what is there and ADD to the end the following:

pcm.!default {
type plug
slave {
pcm "hw:0,0"
rate 48000
}
}


ctl.!default {
type hw
card 0
}



- Auto login to DESKTOP (use raspi-config and change the setting)
- Enable SSH (use raspi-config and change the setting)

#########

CREATING an AP

I have used this excellent TUTORIAL
Note: There is a bug which turns the wlan interface off when the HOSTAPD is on. This is not important and there is no need to correct if you will be using the scenario and the attached script here. We will be manually putting the wlan interface UP and DOWN.

Add my WIFI Script (I need to attach this or publish as a separate post later: wifi.sh) to your home directory and start it at BOOT with adding a line (/path/to/your/script.sh &) to the file sudo nano /etc/rc.local. Then add a crontab job in order to run this script every minute:

sudo crontab -e

Add the following line:
* * * * * sudo /home/pi/wifi.sh > /home/pi/wifilog.txt

Create a log file at your home directory named wifilog.txt to which the output of the crontab job will be written every time when it is run
cd /home/pi
sudo touch /home/pi/wifilog.txt

*if you want to run it more seldom you can change the first "*" to "*/2", 2 minutes or "*/5" min etc.

As an alternative – if you will not be using internet connection – you can create an Ad hoc network instead. I tried this
TUTORIAL
Note: I could get the Raspi connected as a client and everything worked fine when a mobile phone's HOTSPOT used. However, in a ad-hoc environment, I could get the SSID name advertised, but could not manage to make a proper connection or uniterrupted streaming using this.

#########

AIR PI / SHAREPORT (with iOs 6 hack)
Use this this TUTORIAL – everything needed is there including the iOs 6 hack!

#########

Check / test / check and make sure that everything is running as intended. Make proper adjustments, ask questions, do some google-search and make sure the first part of the project is over and you are able to STREAM from your phone to the RASPI using Air Play. Now we need to be able to stream from RASPI and connected USB STORAGE. For that we need the MPD and that is why you came here at the first place, right?

#########

INSTALL MPD OVER Raspberry PI

Go back to the first page and do some reading there

Once you managed to get the MPD streaming, download MPoD for iphone or MPDroid for android or Genome Music Player or ARIO for your Raspi, get the VNC connection and play your music via your car's stereos to which the raspi is connected using a 3.5mm plug.

#########

TO – DO LIST

So far I am very happy with this setting and everything is sorted out automatically (almost). Now I want to have a nice full-window banner showing the "Now Playing" INFO with song & artist name, duration, number of the track and the album cover on the server-side. This should be displayed on the attached 7" display. I have been reading and doing some testing. So far, I could only get an info buble with basic information. However, I could not get the album cover displayed yet. In additon, the present banner is very small and located at the upper right corner of the monitor. Any suggestions are very welcome. Then the project will be finally ready.

Part 4: A SCRIPT FOR NOTIFICATION & ALBUM COVER ART RETRIEVAL

aht961 said
TO – DO LIST

So far I am very happy with this setting and everything is sorted out automatically (almost). Now I want to have a nice full-window banner showing the "Now Playing" INFO with song & artist name, duration, number of the track and the album cover on the server-side. This should be displayed on the attached 7" display. I have been reading and doing some testing. So far, I could only get an info buble with basic information. However, I could not get the album cover displayed yet. In additon, the present banner is very small and located at the upper right corner of the monitor. Any suggestions are very welcome. Then the project will be finally ready.

I am referring to my post above. This was the missing part of the project. Now I have found a nice solution, which is quite nice, however, requires further improvements. I will describe the process in the following for those who are willing to try it.

The basics are straight forward. When MPD plays a song, a notification bubble with an album cover, song and related info is displayed on the upper right corner for a 5 seconds. If a cover could not be found in the default folder, a query is made to http://www.albumart.org and if a match is found it is downloaded in the default directory. The script uses for displaying the notification (notify-osd).

We need these:
mpc #Required (Command line MPD client: probably you already have)
Notify-OSD#Required (check if you have it already installed)
libnotify-bin #Required (not very sure about this, since I have installed this earlier)
ImageMagick #Optional
Ario #Optional (if you want to download cover art)

Lets install these
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install packagename
Substitute package name with: mpc notify-osd libnotify-bin imagemagick ario

I have been looking for a ready solution and tested a few options. Only with a 3 year old script by pbrisbin and KittyKat I have managed to have the notification displayed but with no album cover. There were few typo mistakes and changes in the URL and I have changed them. Before running the script, first install the packages above and TEST if notification is functioning.

notify-send "Hello World"

You should see this at your display's upper right corner. If you don't see, you should try to sort this out before you proceed with the following. I was using a VNC connection and could not see anything. I had to define my display before the notify-send command.

For VNC connection it was DISPLAY=:1 and for the primary attached monitor DISPLAY=:0.0
Try both and check which one works for you. So, first you export the display then the command

export DISPLAY=:1; notify-send "hello" or
export DISPLAY=:0.0; notify-send "hello"

You see it on the monitor – great, now you are ready to proceed.

A. CREATE THE NOTIFICATION SCRIPT

Copy the code below and save it as mpdnotify at your home directory /home/pi

###########################################################################

#!/bin/bash
###########################################################################
# pbrisbin 2010
# http://pbrisbin.com:8080/bin/bashnotify
# modify the config after it's written!
#
# modified by KittyKatt (http://www.silverirc.com/kittykatt/) 2010
#
# modified and few bugs corrected by AT aht Tekay @ 2013
###########################################################################
### utilities {{{
message() { echo 'usage: mpdnotify [start|stop|restart]'; exit 1; }
logger() { echo "$(date +'[ %d %b %Y %H:%M ]') :: $*" | tee -a "$log"; }
errorout() { logger "error: $*"; exit 1; }
# }}}
### write config file {{{
write_config() {
if [ ! -f "$config" ]; then
logger "NOTE: writing example config to $config…"
logger "you should edit this file before starting the deamon"
cat > "$config" << EOF
#!/bin/bash
#
# mpdnotify config – any valid bash is allowed, you
# only need to define handle_event() for the deamon
# to run properly
#
# \$mydir exists, and it's value is $mydir
# Constants
if [ "\$MPD_HOST" ]; then HOST="\$MPD_HOST"; else HOST="localhost"; fi
if [ "\$MPD_PORT" ]; then PORT="\$MPD_PORT"; else PORT="6600"; fi
MPD_TCP="/dev/tcp/\$HOST/\$PORT"
coverDir="\$HOME/.covers" # THE DIR FOR YOUR COVERS
tmpCover="/tmp/cover"
baseCover="\$HOME/extras/base.png" # THE DIR FOR YOUR DEFAULT IMAGES
topCover="\$HOME/extras/top.png" # THE DIR FOR YOUR DEFAULT IMAGES
noCover="\$HOME/extras/NOCOVER.png" # THE DIR FOR YOUR DEFAULT IMAGES
myPID="\$HOME/.config/mpdnotify/pid"
mpdPID=\$(pidof mpd)
mpdArtist="Could not find Artist's name"
mpdTitle="Could not find Song's title"
mpdAlbum="Could not find Album's name"
mpcLength="Could not find Song's length"
mpcInfo="Cound not find Song's info"
showCover="true"
expireTime="5000"
#logout="true"

function mpd_sndcommmand() {
# \$1 command
exec 5 \$MPD_TCP 2>/dev/null
[[ \$? -gt 0 ]] && return 1
echo \$1 >&5
echo "close" >&5
tmp=\$(cat &-
_ret=\$(head -n -1 <<< "\$tmp" | tail -n +2)
return 0
}

function mpd_getinfo() {
mpd_sndcommmand currentsong
[[ \$? -gt 0 ]] && return 1
_tmp=\$_ret
mpdTitle=\$(grep "^Title: " <</dev/null | sed "s/Title: //")
mpdArtist=\$(grep "^Artist: " <</dev/null | sed "s/Artist: //")
mpdAlbum=\$(grep "^Album: " <</dev/null | sed "s/Album: //")
_songtime=\$(grep "^Time: " <</dev/null | sed "s/Time: //" | cut -f 1 -d
(( _mm=\$_songtime / 60 ))
[[ \${#_mm} -eq 1 ]] && _mm="0\$_mm"
(( _ss=\$_songtime – \$_mm * 60 ))
[[ \${#_ss} -eq 1 ]] && _ss="0\$_ss"
mpdLength="\$_mm:\$_ss"
mpd_sndcommmand "status"
_tmp=\$_ret
mpdSongID=\$(grep "^songid: " <</dev/null | sed "s/songid: //")
mpdPlaylistL=\$(grep "^playlistlength: " <</dev/null | sed "s/playlistlength: //")
}

function fetch_cover() {
###################################################################################
# CHANGE THE FOLLOWING LINE TO MATCH YOUR COVER TAG in coverDir

coverjpg="\$coverDir/\${mpdArtist}-\${mpdAlbum}.jpg"

# If you have changed this, you should change the URL below as well
###################################################################################
album=\$1
file="\$coverjpg"
if [ ! -f "\$file" ] ; then
logger "\$file is not in covers… " >/dev/null
###################################################################################
# CHANGE THE FOLLOWING IF YOU HAVE CHANGED THE COVER TAG ABOVE OR IF THE URL FOR
# SEARCHING AT albumart.org changes

url="http://www.albumart.org/index.php?skey=\${mpdArtist// /+}-\${mpdAlbum// /+}&itempage=1&newsearch=1&searchindex=Music"

###################################################################################
cover_url=\$(curl -s "\$url" | awk -F 'src=' '/zoom-icon.jpg/ {print \$2}' | cut -d '"' -f 2 | head -n1)
if [ -n "\$cover_url" ]; then
logger "\$file retrieved and placed in covers directory…" >/dev/null
wget -q -O "\$file" "\$cover_url"
else
logger "ERROR: Album cover not found online. Searched for: \${album// /+}" >/dev/null
fi
fi
}

handle_event() {
###################################################################################
# CHANGE THE FOLLOWING LINE TO MATCH YOUR COVER TAG in coverDir

coverjpg="\$coverDir/\${mpdArtist}-\${mpdAlbum}.jpg"

# NO CHANGES REQUIRED BELOW
###################################################################################
if [[ -z \$mpdPID ]]; then
echo "MPD is not currently running!"
if [[ -f "\$myPID" ]]; then
rm "\$myPID"
fi
exit
else
mpd_getinfo
if [ "\${showCover}" = "true" ]; then
if [ -f "/tmp/cover" ]; then rm /tmp/cover; fi
if [ -f "\$coverjpg" ]; then
cp "\$coverjpg" /tmp/cover
else
fetch_cover "\$mpdAlbum"
if [ -f "\$coverDir/\$mpdAlbum" ]; then
cp "\$coverDir/\$mpdAlbum" /tmp/cover
else
cp "\$noCover" /tmp/cover
fi
fi
mogrify -resize 144x144! \$tmpCover
# convert \$baseCover "\$tmpCover" -geometry +4+3 -composite \$topCover -geometry +0+0 -composite "\$tmpCover"
mpdAlbum=\$(echo "\$mpdAlbum" | sed -e 's/&/&/')
mpdTitle=\$(echo "\$mpdTitle" | sed -e 's/&/&/')
mpdArtist=\$(echo "\$mpdArtist" | sed -e 's/&/&/')
[[ "\${#mpdArtist}" -gt "25" ]] && mpdArtist=\$(echo "\${mpdArtist:0:25}…")
[[ "\${#mpdTitle}" -gt "25" ]] && mpdTitle=\$(echo "\${mpdTitle:0:25}…")
[[ "\${#mpdAlbum}" -gt "25" ]] && mpdAlbum=\$(echo "\${mpdAlbum:0:25}…")
notify-send --expire-time="\${expireTime}" -i "\${tmpCover}" "$(echo "${mpdTitle}")" "\$(echo "By: \${mpdArtist}"; echo "From: \${mpdAlbum}"; echo "Length: \${mpdLength}"; echo "Position: \${mpdSongID} / \${mpdPlaylistL}")"
else
notify-send --expire-time="\${expireTime}" "$(echo "${mpdTitle}")" "\$(echo "By: \${mpdArtist}"; echo "From: \${mpdAlbum}"; echo "Length: \${mpdLength}"; echo "Position: \${mpdSongID} / \${mpdPlaylistL}")"
fi
if [ "\$logout" == "true" ]; then
echo -e "\$mpdTitle \n \$mpdArtist \n \$mpdAlbum \n" > \$HOME/mpdout
fi
fi
}

EOF
exit 0
fi
. "$config"
type -p handle_event || errorout 'handle_event() not defined, check your config'
}

# }}}

### start/stop deamon {{{
start_daemon() {
[ -f "$pid" ] && errorout "file found at $pid, daemon already running?"

# start listening in background
( while read -r; do
handle_event
done < "$pid"
}

stop_daemon() {
if [ -f "$pid" ]; then
kill $(cat "$pid") || errorout 'error stopping daemon'

rm "$pid"
fi
}

# }}}

### constants

if [ "$XDG_CONFIG_HOME" ]; then
mydir="$XDG_CONFIG_HOME/mpdnotify"
else
mydir="$HOME/.config/mpdnotify"
fi
config="$mydir/config"
pid="$mydir/pid"
log="$mydir/log"
pipe="$mydir/pipe"

### run it

if [ ! -d "$mydir" ]; then
mkdir -p "$mydir" || errorout "unable to create my dir $mydir"
fi

write_config

case "$1" in
start) start_daemon ;;
stop) stop_daemon ;;
restart) stop_daemon; sleep 3; start_daemon ;;
status) handle_event ;;
*) message ;;
esac

#######################################################################
# E N D O F S C R I P T
#######################################################################

How to run: Install mpdnotify at your home directory and run it as a daemon:
Remember to make it executable first

sudo chmod +x /home/pi/mpdnotify

Then start it:

/home/pi/mpdnotify start

At the first run, you will have the configuration files written at /home/pi/.config/mpdnotify. Adjust the directories in the config file.

You won't be able to see anything yet, since we must add EXPORT DISPLAY commands and get rid of the PID file written from the last session at the next boot. In addition, we want to have this run automatically at each boot. Now we will go through these steps.

B. MAKE A STARTUP SCRIPT AND MAKE IT RUN AFTER YOU HAVE LOGGED TO YOUR LXDE DESKTOP

I have made a script for this. Copy the code below as start_mpdnotify.sh and install it at /home/pi
Adjust the DISPLAY= value if the default does not work.

#################################################################################

#!/bin/bash
######################################################
# By AT aht Tekay @ 2013
# Starting MPD-NOTIFY
######################################################
# SETTINGS
lockfile='/home/pi/.config/mpdnotify/pid'
# Change this to match the dir of your lock file
# You may need to change the DISPLAY number below
######################################################
export DISPLAY=:0.0
if [ -e $lockfile ]; then
pid=`cat $lockfile`
rm $lockfile
export DISPLAY=:0.0
/home/pi/mpdnotify start
exit 1
else
export DISPLAY=:0.0
/home/pi/mpdnotify start
fi
exit 0

#############################################################################
# E N D O F S C R I P T
#############################################################################

We need to run this ONLY after the LXDE Desktop session is started. It won't function if you addd it at e.g. /etc/rc.local. Remember this.

Go to /home/pi/.config/autostart, create a .desktop file including the details below.

cd ~/.config/autostart
touch mpdnotify.desktop

using e.g. nano enter the following lines in the mpdnotify.desktop you have just created
nano mpdnotify.desktop

[Desktop Entry]
Type=Application
Name=MPD Notification
Comment=Starts the now playing notification in MPD
Exec=/home/pi/start_mpdnotify.sh

Save. Go to your desktop menu using GUI: > Preferences > Desktop Session Settings. There you will see a NEW shortcut named MPD Notification: Activate. This will run the script after reboot and the initiation of the LXDE session.

We are all setup. REBOOT and start MPD if it is not already running. After each song you will se a nice notification with album cover, name, title, artist, track. etc. In addition, make an image file named NOCOVER.png and put it in /home/pi/extras. This will be showed if the album does not have an image to display. If you have album covers, you put them in your coverDir="$HOME/.covers". If you don't have. Install, ARIO and install covers usng it. Thereafter, copy all images from ARIO's /covers folder to your default .cover folder. Ario tags the cover image as Artist Group Name-Album Name.jpg. If yours is different, then you should obviously make the adjustments in the scripts above.

I think this should be a selectable default option in e.g. RASPYFI

IMPORTANT NOTE – EDIT:
There is a funny smiley in the middle of the code where reads:
_songtime=\$(grep "^Time: " <</dev/null | sed "s/Time: //" | cut -f 1 -d * This does not belong there!!!! Add ":" ")" there where the * is but nothing else. The forum is not very friendly for posting codes or styling

MISSION ACCOMPLISHED – GOOD LUCK

Thank you for your interest in the project. Nice suggestions. I have few comments, though.

craigcurtin said
One option that you could look at to simplify some of this would be to use a 3g/wireless router – like the TPLink wr-703n – (around $25) – this would connect via ethernet to your PI and will auto connect to your home network through Wireless when in range and through 3G when on the road – this would act as your incar Wifi access point so your head end (android etc) could access the PI over this.

The logic behind Pi is to keep the budget at minimum. If you add a 3G router, you need an additional 3G subscription. Taking into account the amount of time you spend in the car, at least to me, sounds not very practical.

The second problem comes with the power for the router. Then you will need probably a 12V/220V inverter.

If ultimate audio quality was your goal then put a 2nd Pi in the car to act as a NAS with USB HDD and a small ethernet switch to interconnect everything !

Why do you think that adding another Pi would improve the audio quality?

TPlink as Wirelesss Hub/access point and 3G router – this will be permanently mounted to my windscreen for best range
Small 5 port ethernet switch headless Raspberry pi as MPD player with USB DAC – connected to ethernet switch 2nd pi as NAS with 2.5 inch HDD and ethernet connected to switch

As I have said, this is doable if you want to dedicate a 3G subscription for your auto-PI. But if I were you and willing to have an internet connection dedicated to PI in the car, then I would go for a 7" touchscreen monitor for PI and forget the mobile phone and remote connection. Then you will have your HDD, USB DAC attached and also could directly connect to spotify if you wanted, The only reason I needed to have this client/AP options was to use the mobile phone for internet connection.

I am still working out the power setup but as i will have an android in the car for some other automation projects may leave the TPlink permanently powered from a small 12v (7.2ah) battery – this would then be able to receive a command through ssh to wake the PI – which would go to the android to enable a relay to turn on power to the Pi.

Very interesting.

Rysnc will then run from my music collection in the house and download any updates to the Pi NAS ready for the next time i drive off.

I do that by just taking the small 32GB USB drive home or bringing the laptop to the car while I am still in the garden