

In our last article, we learned how to control a Raspberry Pi from a mobile device and, as a bonus, we created a menu to make it even easier to issue commands and control our Pi. We’re back today to put that remote menu to good use because we’re building an amazing Pandora music player we can connect to a stereo in our living room, for example, without a monitor, keyboard, or mouse. Our system will include a web interface served through Node.js so we can control our Pandora player remotely from a mobile phone—all from the comfort of our couch. 🙂 Follow along with me and let’s make this happen!

Note: I originally released this article two years ago and have updated it based on the latest version of Raspbian.

Article Contents

Complete Prerequisites

Prepare your Raspberry Pi

If you have not already followed my Beginner’s Guide to Installing Node.js on a Raspberry Pi, I recommend that you take a look at that now. In this guide, I equip you with the knowledge needed to build an awesome Raspberry Pi system that can also run in a headless mode. We’re able to avoid a dedicated monitor, keyboard, and mouse, and this is exactly what we need to maximize the awesomeness of our Pandora player.

At the very least, make sure you follow the steps to install Node.js because Node.js will be powering the built-in Pandora web server we’ll be accessing from our mobile devices.

Create Pandora account

If you do not already have a Pandora account, go ahead and visit Pandora.com and create one now. Pandora is “free personalized radio that plays the music you love”. What’s not to love about that? 🙂

While you are logged into Pandora, go ahead and create a couple of stations. Our remote web interface will ultimately need stations in order to to play music for us.

Install additional packages

We’ll need a couple of additional packages to utilize our Pandora player. First, let’s install pianobar, an amazing console-based pandora.com player underpinning our entire project:

$ sudo apt install pianobar

Next, we’ll install screen , a terminal-based window manager that our software will use behind the scenes in conjunction with pianobar:

$ sudo apt install screen

Install Patiobar

As a next step, we’ll install and configure Patiobar, a web frontend for pianobar created by Kyle Johnson. I was gearing up to create a web interface to pianobar and came across Kyle’s project. He has done an excellent job, and we’ll be leveraging his work to create this fantastic music system.

Go ahead and ensure your terminal session is in your home directory:

$ cd ~

Also, these very next steps require Node.js so make sure you have that installed.

Ok, let’s install Patiobar. Execute this next set of commands one by one from the terminal:

$ git clone https://github.com/kylejohnson/Patiobar.git $ cd Patiobar $ bash install.sh

Excellent! We just made some serious progress and installed the foundational elements needed for our Patiobar web server.

Configure pianobar so it’s ready to be used by Patiobar

Our Patiobar web frontend ultimately uses pianobar behind the scenes to serve up music from Pandora so we need to make sure pianobar is configured and in working order first.

Launch the pianobar configuration file for editing using the Leafpad text editor:

$ leafpad ~/.config/pianobar/config &

The contents will look something like this:

user = you@user.com user = user@example.com password = password #autostart_station = 123456 audio_quality = high event_command = /home/pi/Patiobar/eventcmd.sh fifo = /home/pi/Patiobar/ctl tls_fingerprint = FC2E6AF49FC63AEDAD1078DC22D1185B809E7534

Substitute the user parameter with your Pandora user account email, and substitute the password with your Pandora password, and save your changes.

Great work! We’re making excellent progress and we’re ready to launch pianobar by itself to confirm it works. Connect a set of earbuds or speakers to the audio output jack of your Raspberry Pi. Get ready to hear some music!

Issue the following command to launch pianobar:

$ pianobar

At this point, pianobar should log into Pandora and prompt you to select a station for listening. Now, select the default station that you would like to start each time the Raspberry Pi music player starts. You will be able to change this station from the web interface that is provided, but we need a starting station to bootstrap our player each time it starts. The pianobar station selection dialog will look something like this:

[?] Select station: 2 |> Station "David Nevue (Holiday) Radio" (3749270268933429865)

After selecting a station, hit Ctrl+C to quit. If Ctrl+C does not work, try Ctrl+\ instead.

You will need the long station number listed in parentheses, 3749270268933429865 , as shown in our example above, for the next step.

Edit the pianobar configuration file one more time:

$ leafpad ~/.config/pianobar/config &

Replace the existing autostart_station line with the long station number you obtained above. Be sure to remove the “#” from the beginning of the line so pianobar can read the autostart_station configuration information.

autostart_station = 3749270268933429865

Save your changes and launch pianobar again.

$ pianobar

This time, pianobar should jump right in and begin playing your default station without intervention required by you. Assuming this is the case, you are ready to finish the installation so we can use pianobar with the awesome Patiobar web frontend powered by Node.js.

Create Patiobar start and stop scripts

Okay, let’s create a couple of scripts to make it easy to start and stop Patiobar.

Create bin directory to make our menu command accessible from any directory

First, we will create a directory so our scripts will be accessible from any directory on our system without the need to provide a full path name to our script.

From the terminal, return to your home directory if you are not already there.

$ cd ~

Next, create a directory called bin :

$ mkdir bin

We will need to edit our .bashrc file to include this bin directory in our PATH variable. This will ensure that any scripts located in our newly created bin directory can be invoked from any directory on our system without needing to include the full path to the script. Let’s first launch a text editor so we can edit the .bashrc file:

$ leafpad .bashrc &

Add the following line to the bottom of this file:

export PATH="$HOME/bin:$PATH"

Save your changes and close the leafpad editor.

To ensure our changes to the .bashrc file are processed right away, invoke this command:

$ source .bashrc

Perfect! We are now positioned to create our Patiobar start and stop scripts.

Create pbstart (Patiobar start) command

We’ll use leafpad once again to create our new command. We’ll call our command pbstart (Patiobar start):

$ leafpad ~/bin/pbstart &

Add the following contents and save the file.

#!/bin/bash cd /home/pi/Patiobar # Kill any old Patiobar processes running pbstop 1> /dev/null screen -S pianobar -d -m bash -c 'pianobar' # The "patiobar" in the end is not needed and is used as an identifier so we can kill it when stopping. # Otherwise, we might kill other "node index.js" processes. node index.js patiobar > /dev/null 2>&1 & echo "Go to http://$(hostname):3000/ to launch the Web interface."

Create pbstop (Patiobar stop) command

Using leafpad once again, create a second command called pbstop (Patiobar stop):

$ leafpad ~/bin/pbstop &

Add the following contents and save the file.

#!/bin/bash echo Closing out Pandora processes... pkill -xf "SCREEN -S pianobar -d -m bash -c pianobar" pkill -xf "node index.js patiobar" echo done

Set user execute bit on the pbstart/stop scripts

Finally, set the user execute bit on both files so the pi user has permission to run the scripts:

$ chmod u+x ~/bin/pbstart $ chmod u+x ~/bin/pbstop

Launch Patiobar and start listening to music!

Okay, here’s the moment of truth. Let’s try out our pbstart command and see if we can start up Patiobar. Remember that we can invoke this command from any directory on our system since it is part of our PATH . Here we go!

$ pbstart

Patiobar should start up pianobar, and you should both hear music and be able to navigate to the Patiobar web interface running on port 3000. For example, my Raspberry Pi host name is called “pandora” so I would navigate to http://pandora:3000 . It’s December and I’m listening to Christmas music so this is what I see when launching the web interface from my mobile phone:



The interface is excellent and we can change stations using the “hamburger” menu in the top right, and pause, skip songs, etc. There’s even album art as you can see!

When you are done listening, stop the Patiobar player so you do not consume all your Pandora minutes:

$ pbstop

Install SSH client on mobile phone to control Pianobar start/stop remotely (optional)

We learned how to control a Raspberry Pi from a mobile device] in our last article and I encourage you to read that article to learn how to install an SSH client on your mobile device so you can invoke terminal commands from your phone. It’s pretty amazing and useful to not be tethered to a laptop or desktop and still log in and interact with your Pi!

After the mobile SSH client is installed you will be able to invoke pbstart from your mobile device to start Patiobar, stop Pianobar with pbstop , and safety shut down your Pi using the following command:

$ sudo poweroff

Utilizing a mobile SSH client is a much better option for shutting down your headless Pi gracefully rather than yanking the power cord out and risking potential corruption of your microSD card.

Add menu for remote control from mobile phone (optional)

To make it even easier to invoke commands, our last article on controlling a Raspberry Pi from a mobile device also included a bonus section on creating a menu system. You can follow the steps in that article to create a menu system that looks something like this for our current Pandora player project:



After following the steps in the controlling a Raspberry Pi from a mobile device article, you can create a file called menu2.sh in the same directory as the rmenu command like this:

$ leafpad ~/bin/menu2.sh &

…and add the following contents:

show_menu () { # We show the host name right in the menu title so we know which Pi we are connected to OPTION=$(whiptail --title "Menu (Host:$(hostname))" --menu "Choose your option:" 12 36 5 \ "1" "Uptime" \ "2" "Start Pandora" \ "3" "Stop Pandora" \ "4" "Reboot Pi" \ "5" "Shut down Pi" 3>&1 1>&2 2>&3) BUTTON=$? # Check if user pressed cancel or escape if [[ ($BUTTON -eq 1) || ($BUTTON -eq 255) ]]; then exit 1 fi if [ $BUTTON -eq 0 ]; then case $OPTION in 1) MSG="$(uptime)" whiptail --title "Uptime info" --msgbox "$MSG" 8 36 show_menu ;; 2) pbstart msg="Go to http://$(hostname):3000/ to launch the Web interface." whiptail --title "Note" --msgbox "$msg" 8 36 show_menu ;; 3) pbstop sleep 2 show_menu ;; 4) confirmAnswer "Are you sure you want to reboot the Pi?" if [ $? = 0 ]; then echo Rebooting... sudo reboot else show_menu fi ;; 5) confirmAnswer "Are you sure you want to shut down the Pi?" if [ $? = 0 ]; then echo Shutting down... sudo poweroff else show_menu fi ;; esac fi }

This new menu ( menu2.sh ) can then be invoked from rmenu as follows:

$ rmenu -m 2

As a final step (as outlined in the previous article), you can add this rmenu -m 2 command to ~/.profile so the menu starts automatically when you SSH into the Pi from your mobile device.

Launch Patiobar automatically on startup (optional)

If you have a dedicated microSD card for your Pandora player, you might want to start Patiobar automatically each time you power on your Raspberry Pi. This makes it easier to, for example, power on a Pi connected to speakers in your living room without the need to SSH into the Pi upon boot to issue a pbstart command. The downside is that you might be playing music and burning Pandora time when you don’t even realize music is playing. 🙂

To start Patiobar automatically every time you boot, use sudo to edit the following file since this file requires root privileges:

$ sudo leafpad /etc/rc.local &

Add the following line just above the last line in the file with the contents of exit 0 :

sleep 15 && sudo -iu pi /home/pi/bin/pbstart

The /etc/rc.local script runs every time the Pi boots up. We sleep for 15 seconds before invoking the pbstart command under the aegis of the pi user. The 15 second “nap” 🙂 gives time for the network to stabilize before the pbstart script connects to Pandora.com and begins to stream music.

Save the file and close leafpad. Finally, reboot your Pi.

$ sudo reboot

After the Pi finishes its boot cycle (and another 15 seconds after that), you should start hearing music streaming from Pandora automatically!

Troubleshooting in the future (if music does not play)

Sometime down the road, you may be faced with a situation where music does not play. As a first troubleshooting step, remember that the pbstart command must be run to start Pandora and the web interface. Pay attention to the output of the pbstart command for any errors that appear.

Another potential issue could be that the “TLS fingerprint” associated with the Pandora website has expired. When Pandora updates their SSL certificates, a new TLS fingerprint is needed. Keep this in mind in the future when Patiobar stops working and you can’t figure out why. Revisit this section and update the TLS fingerprint as we will describe now.

First, run pianobar as a standalone program separate from Patiobar to verify this is the issue:

$ pianobar

If you do not hear music, but instead see an error message indicating a “TLS fingerprint mismatch”, proceed with the next steps to resolve this issue.

We first need to copy over a handy script included with the pianobar distribution to our current directory so we can retrieve the latest TLS fingerprint:

$ cp /usr/share/doc/pianobar/contrib/tls_fingerprint.sh .

Next, set the user execute bit to make sure we can run the script:

$ chmod u+x tls_fingerprint.sh

Go ahead and invoke this script to retrieve the TLS fingerprint:

$ bash tls_fingerprint.sh

You should see something like this: FC2E6AF49FC63AEDAD1078DC22D1185B809E7534

Next, edit the pianobar configuration file:

$ leafpad ~/.config/pianobar/config &

Replace the existing tls_fingerprint configuration parameter with the new TLS fingerprint obtained:

tls_fingerprint = FC2E6AF49FC63AEDAD1078DC22D1185B809E7534

Run pianobar to verify that it now works before issuing a pbstart to restart Patiobar:

$ pianobar

You should hear music playing and be back in business!

Conclusion

There you have it! We created an amazing Pandora player that can be controlled remotely from a mobile device. We can control our Pandora listening experience through a web interface. As a bonus, we can also start and stop our Pandora player through an SSH interface on a mobile device with a handy menu as well. We are ready to enjoy music with family and friends—and we learned some cool technology tricks in the process!

Follow @thisDaveJ (Dave Johnson) on Twitter to stay up to date with the latest tutorials and tech articles.

Additional articles

Controlling a Raspberry Pi from a Mobile Device with Bonus Menu Too

Beginner’s Guide to Installing Node.js on a Raspberry Pi

Connecting a Raspberry Pi Using an Ethernet Crossover Cable and Internet Connection Sharing

Upgrading to more recent versions of Node.js on the Raspberry Pi