Mopidy Pummeluff

Pummeluff is a Mopidy extension which allows you to control Mopidy via RFID tags. It is as simple as that:

• Register an action to an RFID tag
• Touch that tag on the RFID reader and the action will be executed

Thus, the Mopidy Pummeluff extension adds the following features to Mopidy:

• A radically simple web UI which can be used to manage the RFID tags
• A daemon which continuously reads RFID tags in the background and executes the assigned actions

There are several actions included, such as replacing the tracklist with a desired URI, setting the volume to a specific level or controlling the playback state.

Hardware

Requirements

To get the whole thing working, you need at least the following hardware:

• A Raspberry Pi 3 Model B
• An RC522 RFID module (RC522 on AliExpress for approx. USD 1)
• RFID tags (ISO 14443A & Mifare should work, 14443A tags on AliExpress for approx. 0.4 USD per tag)
• Female dupont jumper wires (female dupont jumper cables on AliExpress for approx. 1 USD)

Optionally you can also add two buttons to the RPi, which can be used for power & playback control:

• Two momentary push buttons (momentary push buttons on AliExpress for approx. USD 1-2)

Pummeluff also supports a status LED, which lights up when Pummeluff (i.e. Mopidy) is running. You can go with a separate LED, just make sure it can handle 3.3V or add a resistor. There are also push buttons with integrated LED's available, for example these 5V momentary push buttons on AliExpress.

Note

The project will probably run on other RPi models, but I've only tested it on the 3B. The RPi 3B+ should also work fine, as the GPIO pins are identical. I don't know about RPi 1 or 2, but you can give it a shot.

Connecting the RC522 module

Please connect the RC522 RFID module to the RPi as follows:

• RC522 pin 1 [SDA ] ––– RPi pin 24 [SPI0 CE0 ]
• RC522 pin 2 [SCK ] ––– RPi pin 23 [SPI0 SCLK]
• RC522 pin 3 [MOSI] ––– RPi pin 19 [SPI0 MOSI]
• RC522 pin 4 [MISO] ––– RPi pin 21 [SPI0 MISO]
• RC522 pin 5 [IRQ ] ––– RPi pin 18 [ GPIO 24 ]
• RC522 pin 6 [GND ] ––– RPi pin 20 [ GND ]
• RC522 pin 7 [RST ] ––– RPi pin 22 [ GPIO 25 ]
• RC522 pin 8 [3.3V] ––– RPi pin 17 [3.3V PWR ]

Please have a look at the Raspberry Pi SPI pinout if you want to have a graphical view of the RPi GPIO pins.

Note

This connections are only valid for the RPi model 3B and 3B+. If you want to use another RPI model, make sure you're using the correct pins.

Connecting the buttons (optional)

To control the RPi, you can optionally connect several buttons as well. Pummeluff supports the following button interactions:

• Power button: Shutdown the Raspberry Pi into halt state & wake it up again from halt state
• Playback button: Pause and resume the playback
• Stop button: Stops the playback
• Previous button: Changes to the previous track in the playlist
• Next button: Changes to the next track in the playlist

Please have a look at the default Pummeluff config for the default button GPIO pin numbers, respectively the configuration options to change the them.

The buttons must shortcut their correspnding pins against GND (e.g. pin 6). For example for the power button:

• Button pin 1 (e.g. C) --- RPi GND pin (e.g. pin 6)
• Button pin 2 (e.g. NO) --- RPi pin 5 [GPIO 3]

Connecting the status LED (optional)

If you want to have a status LED which is turned on when the RPi / Mopidy is running, you can connect an LED to these pins:

• LED - pin --- RPi GND pin (e.g. pin 6)
• LED + pin --- RPi LED pin

Please have a look at the default Pummeluff config for the default LED GPIO pin number, respectively the configuration option to change it.

Installation

Prepare Raspberry Pi

Before you can install and use Mopidy Pummeluff, you need to configure your Raspberry Pi properly.

We want to enable the SPI interface and give the mopidy user access to it. This is required for the communication to the RFID module. Enter this command:

sudo raspi-config

In the configuraton utility, Enable the SPI under 5 Interfacing Options – P4 SPI.

After that, add your mopidy user to the spi and gpio group:

sudo usermod -a -G spi,gpio mopidy

If you're planning to use a button or RFID tag to shutdown the system, you also need to create a sudo rule, so that the mopidy user can shutdown the system without a password prompt:

echo "mopidy ALL = NOPASSWD: /sbin/shutdown" > /etc/sudoers.d/mopidy

Install via pip

The recommended way to install Mopidy Pummeluff by using pip and thus by executing the following command:

sudo python3 -m pip install mopidy-pummeluff

Hint

If you get an error that spidev could not be found, run sudo python3 -m pip install spidev first. This is an issue related to the pi-rc522 Pypi package.

Install from source

Alternatively, you can also install Mopidy Pummeluff from source, by running this command:

sudo su -
cd /usr/src
git clone https://github.com/confirm/mopidy-pummeluff.git
cd mopidy-pummeluff
python setup.py install

Hint

If you get an error that spidev could not be found, run pip install spidev first. This is an issue related to the pi-rc522 Pypi package.

Configuration

Activate and configure the Mopidy HTTP extension and make sure you can connect to the Web UI. The minimal config looks like this:

[http]
enabled = true
hostname = 0.0.0.0

Have a look at the default Pummeluff config for all configuration options.

Usage

Open the Mopidy Web UI (i.e. http://{MOPIDY_IP}:6680/). You should see a pummeluff web client which can be used to regsiter new RFID tags.

Contribution

Please follow these development guidelines when contributing to this project.