Infotainment System - Technical Overview

Architecture

The core of the Infotainment system is written in Node.js. It establishes an Express web server, then uses Socket.IO to manage connections to different control and/or display surfaces. Because display, audio and control surfaces are coded as web pages served up by the Express server, the Infotainment system creates a device-agnostic ecosystem, where any number of devices on any combination of platforms can participate (assuming they support a semi-modern browser).

In general, the Infotainment System can be logically brpagesoken down into three parts: the host script, the audio handler(s), and skins (display/input pages).

Host script

The host script operates as the beating heart of the Infotainment system. It manages the services for the display/input interface pages, listens to variable stream information from a miniSim, coordinates interface input, and broadcasts system state data back to the miniSim.

For it's real time interface to a miniSim, the Infotainment system leverages the Route Table to supply miniSim variable data streams (speed, position, ...) as well as write it's own back to the miniSim's shared memory.

Audio handler(s)

By default, a single audio page (infotainment_audio.htm) is included. This page can handle 3 channels of stereo playback:

• Media playback
• Alert (temporarily mutes media playback on play)
• Notify

Media playback handles the general audio playback for the media store (defined in the infotainment_config.txt file) and "radio" media streams.

The alert channel is meant for driver alerts. Playback from this channel automatically lowers the volume of the media playback channel while alerts are in progress.

The notify channel is used primarily for audio cues within the vehicle. Its playback does not alter the other two channels' volume.

Skins

Individual web pages serve up visual interfaces/control surfaces, depending on the desired output. This includes (but is by no means limited to):

• Standard OEM-like infotainment interfaces
• Reconfigurable instrument cluster displays
• General touch and/or voice interfaces
• Head-up displays (HUDs)
• "Alert" devices

By default, the Infotainment System includes an interface for an approximation of the Toyota Entune center stack system (main infotainment and researcher "mirror").

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Output

UDP

The host script outputs a UDP stream to an IP and port defined in the infotainment_config.txt file in the root directory of the Infotainment System install. By default, four variables are shared from the infotainment system and fed back into the miniSim's shared memory:

Cell name	Length, type	Description	Default value
AUX_Info_Screen	1 short	The screen ID of the current active screen/menu of an attached page/skin	0
AUX_Info_Button	1 short	The button ID of the last button pushed on an attached page/skin	0
AUX_Info_Cursor	2 shorts	The relative X,Y position of a detected touch event on an attached page/skin. When no touch is detected, these two values default to -9999, -9999	-9999, -9999
AUX_MID_Screen	1 short	If using an attached multi-information display (MID), this variable returns the given "screen ID" of the MID.	-1

• AUX_Info_Screen (1 short)
• AUX_Info_Button (1 short)
• AUX_Info_Cursor (2 shorts)
• AUX_MID_Screen (1 short)