Android Automotive (not to be confused with Android Auto) is tightly integrated with the features of a car Android-based operating system designed for use directly on vehicle head units as part or all of the vehicle system and/or infotainment functionality (e.g. VMS - Vehicle Map Service , EVS - Exterior View System, IVI - In-Vehicle Infotainment, HVAC - Heating, ventilation, and air conditioning etc.).
Android Automotive (instead of android-auto which is not an OS, but just application that provides secondary interface for already existing Android OS) is car-focused version of Android while still giving a similar user experience to android auto.
Android Automotive includes the Android Automotive hardware abstraction layer (HAL) provides a consistent interface to the Android framework regardless of physical transport layer. This vehicle HAL is the interface for developing Android Automotive implementations.
System integrators can implement a vehicle HAL module by connecting function-specific platform HAL interfaces (e.g. HVAC, EVS) with technology-specific network interfaces (e.g. CAN or LIN bus). Typical implementations may include a dedicated Microcontroller Unit (MCU) running a proprietary real-time operating system (RTOS) for CAN bus access or similar, which may be connected via a serial link to the CPU running Android Automotive. Instead of a dedicated MCU, it may also be possible to implement the bus access as a virtualized CPU. It is up to each partner to choose the architecture suitable for the hardware as long as the implementation fulfills the interface requirements for the vehicle HAL.
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