The gervifonn is a device to access music stored in a digital music library by interacting with physical CD cases.
The gervifonn displays the currently playing album. You can change the volume, pause playback or skip to the previous/next song. When you put a CD case onto the gervifonn and press the knob, it uses an AI to recognize the album you want to play.
gervifonn.mp4
gervifonn2.mp4
The name "gervifonn" derives from the icelandic words "gervigreind" (Artificial Intelligence) and "fónn" (Record Player).
See below for details of required parts and software. Assemble the gervifonn in the following order:
- Install Raspberry Pi OS (Legacy) on micro SD card and put micro SD card into Raspberry Pi
- Configure Rasberry Pi OS for automatic login, enable wifi, camera and ssh access and install the display drivers provided by the vendor
- Install gervifonn software
- Install pushbuttons, rotary encoder and knob
- Connect camera cable to camera. Put together the right and left half of the case, fitting the camera into the camera holder and threading the power cord through the hole in the back of the case. Make a knot in the power cord as a strain relief. Use screws and nuts to secure
- Use screws to fix Raspberry Pi on bottom part of the case
- Connect the pushbuttons and the rotary encoder like this using the flat ribbon cable:
- Connect the camera cable to the Raspberry Pi and install display
- Insert bottom part of case and secure with screws and nuts
The case is 3D printed. The OpenSCAD source and generated STL files can be found under case. The case is made from three parts, for assembly 12 M3 bolts and 8 M3 nuts are needed.
The heart of the gervifonn is a Raspberry Pi 3 B+. Additionally the following parts were used (links to amazon.de, not sponsored):
- Raspberry Pi Camera Revision 1.3 (use the long cable, not the 15cm one)
- 3.5 inch 320*480 Resolution Touch Screen
- 12mm pushbuttons
- KY-040 Rotary Encoder
- Knob for the Rotary Encoder
- 10 Pin 2,54mm Pitch flat ribbon cable
- A bit of extra wiring
- Micro-SD card
- Power supply for Raspberry Pi 3
The gervifonn uses Raspberry Pi OS as a base.
The additional software running on the gervifonn can be found under src. Install the requirements with pip install -r requirements.txt and place src\gervifonn.desktop into the /home/pi/.config/autostart/ directory of your raspberry. You might want to adapt the path to the gervifonn.py, the path to the music directory, the hostname of the MPD server, and the Snapcast server and client if used.
The AI-model needs to be trained on a more powerfull (linux) machine than a raspberry pi. A GPU with CUDA support is recommended, see here for installation hints for the required libraries. Install the python libraries needed with pip install -r training/requirements.txt. To train the model use training/train_gervifonn.py, with the path to your music folder and a folder with background images as arguments (details see below).
The resulting gervifonn.tflite model needs to be placed together with the generated labels.txt on your raspberry pi in the same folder as src/gervifonn.py.
The gervifonn currently expects the following environment:
The music library should be structured in the way Jack creates it, meaning one folder per Artist with subfolders for each album. Samplers are stored in the Various folder.
In addition, a cover image must be present in each folder, named cover.png. Optionally, you can place additional cover images in a subfolder called gervifonn inside each album. This will also be done by the gervifonn when you are using it. To simplify taking cover pictures of a bigger collection, you can use src/gervifonn_capture_covers.py. Start it on the gervifonn, place the album on the gervifonn and press the leftmost button. It will take a picture in the correct format, display it and save it to the current folder. You can then put the next album on the gervifonn and press the leftmost button again. (Hint: use DISPLAY=:0 in front of the command when connected via ssh).
As albums with multiple CDs only have one cover, only place the cover.png in the first folder and create symlinks called next linking to the following CD.
To recap, here is an example folder structure:
Artist A
Album 1
gervifonn
123.png
cover.png
Track X.ogg
Track Y.ogg
...
Album 2
gervifonn
456.png
789.png
cover.png
Track I.ogg
Track J.ogg
...
...
Artist B
Album 1 CD 1
gervifonn
abc.png
cover.png
Track X.ogg
...
next (symlink to ../Album 1 CD 2)
Album 1 CD 2
Track Y.ogg
...
...
The actual playback of the music is handled by the Music Player Daemon. The MPD should be configured to read in your music library and should be reachable from the gervifonn (without authentification). If you don't have an extra machine, it should be fine to install the MPD on the gervifonn as well.
If the audio is streamed from the MPD via Snapcast to the actual playback devices, the volume of one Snapcast client can be controlled by the gervifonn.
gervifonn.py requires the following arguments:
| Argument | Description |
|---|---|
| -m MUSICFOLDER | Path to the music library |
| -n MPDSERVER | Hostname of the MPD server |
Additionally, the following optional arguments are supported:
| Argument | Description |
|---|---|
| -s SNAPCASTSERVER | Hostname of the snapcast server (that will be used to controll the volume). MPD server is used for volume if not given |
| -c SNAPCASTCLIENT | Name of the snapcast client (that will be controlled by the volume knob). MPD server is used for volume if not given |
train_gervifonn.py requires the following arguments:
| Argument | Description |
|---|---|
| -m MUSICFOLDER | Path to the music library |
| -b BACKGROUNDFOLDER | Path to a folder containing random images to make the image recognition more robust |
Additionally, the following optional arguments are supported:
| Argument | Description |
|---|---|
| -s BATCHSIZE | Batchsize for training, affects GPU memory usage. Default: 2 |
| -e EPOCHS | Number of epochs for training. Default: 48 |
| -d | Enable dynamic GPU memory allocation |
When using the gervifonn the display will show the current function of the buttons and the rotary knob. The three buttons on the left of the screen match the pushbuttons. On the right of the screen you can see what turning and pushing the knob will do.
- The default screen of the gervifonn will display the currently playing album cover, artist, album title and song title. The slider at the bottom shows playback position inside the song, the slider at the right the current volume:
The three buttons can be used to pause/continue and switch songs. Turning the knob will change the volume. You can also use the slider below the cover to change the position in the song and the slider to the right to change the volume. To change the playing album, place the case on the gervifonn and press the knob.
-
While the gervifonn is identifying the CD the display will show the picture taken by the camera:
-
When the gervifonn identified the CD it will show the cover, artist and title of the album:
The left button cancels the change and goes back to the default screen. The middle button confirms that the CD was identified correctly and will start to play it. The right button can be used to select the correct album if the CD was not identified correctly.
- When the CD was not identified correctly, the display shows a list of all your albums:
The left button cancels the correction and goes back to the previous screen. You can either use the touchscreen or turn the knob to select the album you put on the gervifonn. Then you can press the knob to confirm your selection and start playback.