Embedded & Engineering Insights
Around 300 car models are Android Auto-ready today. Nvidia, the mobile tech supplier, and over 28 car manufacturers have joined efforts to promote the platform, as part of the Open Automotive Alliance. As Android Auto gains traction, it is now moving towards becoming integrated infotainment, communication, and car dashboard solution.
How Android Auto works
Android Auto first came out as a way to turn the rather limited infotainment systems into a smarter solution.
For the time being, the task of Android Auto is to extend the Android platform into the car. It does that by opening the way for the smartphone to broadcast and manage a user interface onto the vehicle’s touchscreen.
The car and the phone are connected via USB cable, which has two key advantages: bandwidth and power supply. For efficiency reasons, calls continue to be transmitted to car speakers via Bluetooth.
Once connected, the app handles five major functionalities, using the car’s display for all of them: maps, music, communication (calls and text), voice actions, and other related apps. Some other apps that can be integrated are Google Play Music, Google Now, Hangouts or Skype.
All the processing is done by the mobile device itself, with the car’s touchscreen working as an extension. This approach places a significant load on the phone’s battery, which is why Google recommends fast-charging USB ports on vehicles that use Android Auto.
With Android Auto, a driver’s mobile device will have access to several of the car’s sensors and inputs: GPS and high-quality GPS antennas, steering-wheel-mounted buttons, sound system, directional speakers, directional microphones, wheel speed, compass, and mobile antennas.
Android Auto software components
The Android Auto app on the smartphone/tablet and the Google Receiver Library, hosted on the car’s computing unit are the two main components. The Android Auto app is available in Google Play Store, in 31 countries – see here the official list. As for the car-side component, it relies on the integration of the Google Receiver Library (GRL) with the car’s software platform. It comes as a bundle of C++ software libraries that are offered under NDA by Google to its automotive partners only. The GRL works on Android, Linux, and Windows CE platforms.
The purpose of the libraries is to ensure the connection with the Android Auto app on the smartphone and to manage callbacks triggered by various user-generated events (such as a tap on the screen), or by software-generated events (such as stopping music when receiving a phone call).
Android Auto and the safety approach
While extending Android functionalities to the car’s dashboard sounds appealing, there are several safety matters to consider. To avoid driver distraction, it does not allow video streaming, nor the use of custom apps or manual texting. However, the speech-to-text function successfully replaces texting while driving.
Moreover, the interface is limited to 5 layers of depth – meaning that drivers don’t have to navigate tricky menus – and scrolling is limited to only two swipes.
So, when choosing a song from your alphabetical playlist, AC/DC will stand a better chance than ZZ Top. And Annie will be easier to call than Serena if you do it manually. To access the bottom of the list you will need to use vocal commands, which are triggered by saying OK Google out loud.
If for some reason, you don’t want to do that, the other option is to slow down to below 5 km/h.
In the future, Android Auto will connect to other car data as well. The app will be then able to report low tire pressure, for instance, or the right time for an oil change.
Another feature that Google is working on is the replacement of the USB connection with a WiFi communication channel, which is fast and reliable. Why not use the already ubiquitous Bluetooth? It does not have the speed, bandwidth, and reliability the WiFi can provide.
To make things even further, the next step will be to have Android Auto built-in with the car, rather than using the phone app. Take a look at this prototype presented by Google last year. It is based on a Snapdragon 820 processor installed in a Maserati.