Overview

Explore features and capabilities of Hudiy.

Introduction Requirements Interface Android Auto CarPlay API Web view Applications Dashboards Overlays Audio Bluetooth Reverse camera Companion app

Previous Next

Hudiy is an advanced software designed to help you build and expand your own custom infotainment system.

It provides core functionalities such as communication via the OBD-II interface, hands-free calling, multimedia playback, Android Auto, CarPlay, and much more.

Hudiy supports extensive customization including:

customizing the appearance of the UI
creating your own menus
adding shortcuts to frequently used functions
creating custom applications written in HTML/JavaScript that can be fully integrated with Hudiy
creating custom dashboards and integrate your own widgets written in HTML/JavaScript
creating custom overlays written in HTML/JavaScript

Hudiy exposes an API for external systems to retrieve data, perform actions, and integrate with application features. It also provides a special JavaScript object, hudiy, to user-created HTML/JavaScript elements to enable even deeper integration with the application.

The Hudiy application is designed to work on Raspberry Pi hardware. Thanks to the extensive Raspberry Pi ecosystem, you can choose hardware such as audio devices, screens, or controllers that perfectly match your needs.

For more detailed documentation visit our GitHub page.

See the gallery for a visual overview of Hudiy’s interface and features

Mandatory:

Raspberry PI OS 64 bit Desktop (Bookworm)
Raspberry PI 4B or 5 with minimum 2GB of RAM
8GB of free storage space
Display with resolution up to 1920×1080

Optional:

RTL-SDR dongle for FM Radio
CarlinKit CPC-200 CCPA dongle for CarPlay
Microphone for Hands-Free calling and voice assistants
USB or Bluetooth ELM327 adapter for OBD-II communication

The interface automatically scales to screen resolution and supports widescreen, standard, and multi-screen configurations.

The application window can operate in fullscreen mode or be configured with a specific size. Elements such as Android Auto projection, CarPlay projection, the reverse camera view, and overlays can each be assigned custom width, height, and x/y coordinates to allow precise positioning on the screen.

The interface can be controlled using both touch and key events. Navigating via keys is mapped to the following events:

Scroll left
Scroll right
Move focus left
Move focus right
Move focus up
Move focus down
Go back

Supported Key Bindings:

Right right arrow
Up up arrow
Down down arrow
Left left arrow
Back escape
Scroll left 1
Scroll right 2
Home h
Toggle input focus (between projection, native UI and overlays) t
Voice assistant (for projections) m
End voice call o
Answer voice call p
Phone menu g
Go to media player j
Navigation menu f
Play x
Pause c
Previous media v
Next media n
Toggle play/pause b

Actions

Actions are the primary trigger mechanism in Hudiy. Actions serve as triggers for:

displaying menus
displaying dashboards
launching applications
controlling volume
controlling audio playback
controlling voice calls
controlling the reverse camera
controlling Android Auto and CarPlay projections

Actions can be triggered through buttons, widgets, overlays, or API.

Theming

Hudiy follows the guidelines of Material 3 Design.

All icons used in Hudiy are defined in fonts to ensure perfect scalability across various resolutions.
You can provide your own font with icons and use it in configured shortcuts or menus.

Material 3 Design defines two themes: dark and light.

For both dark and light themes, you can define a source color and set the contrast level.

See the Material Theme Builder for a live preview of colors based on the selected source color.

Backgrounds

Hudiy allows you to define a custom image file as the background for each menu in both dark and light themes.
Menus are identified by their corresponding actions.

Shortcuts

Shortcuts for frequently used actions can be placed on the bottom bar.

Each shortcut has a configurable icon and an associated action.

The available space on the bottom bar can be used for shortcuts, but it is limited by the status icon container.

Hudiy supports emulation of an Android Auto-capable head unit. Android Auto can be connected via both USB and Wi-Fi.

For wireless connections, Hudiy can create a Wi-Fi hotspot that the phone connects to in order to stream projection data.

Alternatively, it is also possible to use an existing external Wi-Fi network instead of the built-in hotspot.

Hudiy can retrieve media metadata and navigation information from Android Auto, and exposes this data through the API.

CarPlay projection is served via CarlinKit CPC200-CCPA dongle. CarlinKit CPC200-CCPA supports both USB and Wi-Fi connections.

Hudiy can retrieve media metadata from CarlinKit CPC200-CCPA, and exposes this data through the API.

Hudiy exposes an API for external systems to retrieve data, perform actions, and integrate with application features.

There are two endpoints exposed by Hudiy:

WebSocket
TCP

Both endpoints use Protocol Buffers for communication protocol definition.

API Features:

Exchanging metadata for now playing media, navigation maneuvers, projection status (Android Auto, CarPlay), and phone data (voice calls, battery level, signal strength)
Controlling the reverse camera
Displaying custom status icons
Displaying custom notifications
Displaying custom toast messages
Controlling audio focus
Injecting keystrokes
Injecting cover art
Switching between dark and light themes
Controlling overlay visibility
Registering and dispatching actions
Switching equalizer presets
Querying ELM327 OBD-II device

All custom applications, widgets, and overlays written in HTML/JavaScript are displayed in the Hudiy interface using an embedded web view based on the Chromium engine.

The web view can display local HTML files or load web pages from a provided URL.

All web views can communicate with Hudiy via its API. Hudiy also exposes a special hudiy object with a set of callbacks and properties that can be used to match the current UI theme or handle input events.

Additionally, Hudiy integrates with the Media Session API to control audio focus and playback, and to obtain media metadata.

Note: DRM support plugins are not included with Hudiy, are untested, and must be configured manually by the user.

Input events

For deep integration of HTML/JavaScript elements, Hudiy delivers UI-relevant key events (e.g., directional keys, selection keys) via callbacks, and allows direct touch event handling through the Chromium engine to provide a consistent way of controlling the interface.

Web view elements can be controlled using both touch and key events. Handling key events is optional in web views, but to ensure the best consistency with the native UI, it is recommended to implement it.

Touch events are handled directly by the Chromium engine, whereas key events are delivered to the web view via a set of dedicated callbacks provided by the application.

Users can switch between touch and key input at any time. Both the switch event and the current input method are exposed via callbacks and properties in the hudiy object.

Functionalities of the Hudiy can be extended by custom applications. You can create your own applications in HTML/JavaScript and integrate them with Hudiy using Web view.

Custom applications can be used, for example:

to control various functions of your vehicle, such as climate control or comfort module
to present data gathered from the OBD-II interface via the Api
to display data from any other vehicle-specific interface
to build an advanced camera system

… and much more.

Note: The integration of any vehicle-specific features is the responsibility of the user.

You can also load a link to any web page, such as YouTube Music, and use it as a player for your favorite music.

Dashboards are customizable screens for arranging and displaying widgets. Each dashboard can present different types of information or controls, such as real-time data, system status, media playback, or sensor readings. Multiple dashboards can be created, modified, and switched between for different use cases.

Hudiy includes predefined widgets, but users can also create their own using HTML/JavaScript, and add them to the dashboard as web views.

Widgets

Widgets are part of the dashboard. Hudiy includes predefined widgets such as:

Phone status
Now playing media
Navigation
Date and time

Widgets can also load a local HTML file or a web URL in a web view.

Widgets visible on the dashboard have two width options (narrow and wide) and three height options (small, medium, and large).

Overlays are interface elements that appear on top of all other content. They can, for example, provide data display and quick-access controls.

Custom overlays can be created in HTML/JavaScript and displayed in web views.

Each overlay can have a custom width, height, and screen position (x, y). It can be repositioned using drag-and-drop gestures, the Left, Right, Up, and Down key strokes.

Hudiy includes two built-in overlays: volume controls and navigation.

Overlays can be also used to create split-screen layouts, where, for example, the native UI is shown on one side (e.g., the left) and the overlay is shown on the other side (e.g., the right), displaying additional information or controls.

Hudiy exposes configuration options for two types of sinks: the volume sink and the playback sink. Separate sinks can be configured for audio playback and volume control.

This separation allows greater flexibility — for example, users can route audio through a virtual sink provided by a PipeWire plugin (such as the equalizer or other audio effects), while controlling volume on a different sink directly associated with a physical audio device.

Based on the PipeWire configuration, Hudiy can detect the following speaker setups:

Stereo
FRONT_LEFT, FRONT_RIGHT
4.0
FRONT_LEFT, FRONT_RIGHT, REAR_LEFT, REAR_RIGHT
4.1
FRONT_LEFT, FRONT_RIGHT, REAR_LEFT, REAR_RIGHT, SUBWOOFER

Depending on the detected setup, it is possible to control balance, fade, and subwoofer balance in the audio settings.

Equalizer

The equalizer is implemented as a PipeWire plugin.

The equalizer features 15 adjustable frequency bands, allowing precise control over the audio spectrum. Each band’s gain can be individually configured to shape the overall sound. This allows for custom tuning or the use of predefined equalizer presets.

Equalizer presets are defined in the configuration file. Unlimited equalizer presets can be defined.

Media players

Hudiy supports playback from multiple audio sources, including:

Audio files
Android Auto
CarPlay
FM Radio
A2DP (Bluetooth)

For each audio source, Hudiy attempts to retrieve metadata such as artist, album, title, duration, and cover art. In the case of FM Radio, it can also decode RDS data, including Programme Service and Radio Text.

If cover art is not available from the source metadata, Hudiy can request it from a client connected via the API, using the artist, album, and title as search parameters.

RDS decoding can be enabled or disabled through the configuration.

Hudiy supports Bluetooth with A2DP and AVRCP for media playback and HFP for hands-free calling. The application can also access contacts and call history on a connected phone.

Using the companion app, Hudiy can also receive notifications from the Android phone and display them on the screen.

Bluetooth audio, including A2DP for high-quality media playback and HFP for hands-free communication, is managed by PipeWire. PipeWire handles audio routing, synchronization, and system audio integration.

You can pair and unpair Bluetooth devices directly in Hudiy.

Hudiy displays the camera feed on the screen using GStreamer. The camera feed takes precedence and, when active, is shown above all other visible elements.

The visibility of the camera feed surface can be controlled through corresponding actions or the API.

Camera feeds can alternatively be displayed using web views and the MediaDevices API.

Hudiy comes with a companion app available for Android devices that connects to the system via Bluetooth.

It allows you to display notifications from selected apps directly on the Hudiy screen.
It also provides time synchronization, which is especially useful on systems without a real-time clock (RTC).