Developing Apps for Android Automotive OS – Grape Up

Quite a new droid around. The operating system has been in the market for a while, still missing a lot, but it is out, already implemented in cars, and coming for more. Polestar and Volvo were the first to bring Android Automotive OS to their Polestar 2 and XC40 Recharge.

Other car manufacturers like PSA, Ford, Honda, GM, and more announced that they are going to bring Android Automotive OS to their cars or just hinted about cooperating with Google Mobile Services. Part of implementations coming with Google Automotive Services(GAS): Play Store, Google Maps, Google Assistant, another part without, own app stores, assistants. What’s most interesting for now is to bring your application to the store.

Building apps for the Android Automotive Operating System

Creating an android app for automotive doesn’t differ that much from mobile and is similar to android auto. Starting in an android studio, setting it up for canary releases to get the emulators. The first issue is that Android Automotive OS emulation needs an Intel CPU right now and doesn’t support Apple M1 or AMD. Available emulators start on Android 9(Pie), with Google and a custom one for Polestar 2, Android 10(Q) also with Volvo, skinned to look like XC40 cockpit, Android 11 and freshly released Android 12(API 32) emulators are Google only. To get your hands on custom versions for Volvo or Polestar 2, you need to add links to SDK update sites.

Challenges with Google Automotive Services

Lack of documentation and communication

Diving into the details of development and Android Automotive Operating System in general, the main thing you are going to spot is a problem with documentation and communication with Google, as the Android Automotive car feels like it is lacking options and solutions.

Developers and mobile groups are complaining about it, some of them trying to establish a communication channel and get Google on the other side. Google is not providing a clear roadmap for AAOS, and it is risky or at least could be expensive to develop applications right now. Some parts of the Operating System code hint at certain features, but documentation is silent about them.

Limited options to improve AAOS user experience

Automotive applications are run in a shell (Google Automotive App Host) similar to those for Android Auto, and they do not have Activity thus UI can’t be changed. Apps are automatically rendered, and all of them look similar.

There is still an option to install a regular application through ADB, but this might sound easy only for an emulator. Options for app developers to brand their applications are very limited, actually it is just an app icon at the top side of the screen and a color of progress bars, like those showing how much of a podcast or song you listened to already.

Car manufacturers and automotive OEMs have more options to reflect their brand and style of an interior. They can customize colors, typography, layouts, and more. There is still a requirement to follow design patterns for automotive, and Google is providing a whole design system page.

Mandatory review

Applications submitted to the store are mandatory for an additional review. Reviewers have to be able to perform a full check, logins, payments, etc., so they need to be provided with all required data and accounts. That adds additional uncertainty with innovation and going beyond what is expected, as the reviewer has to agree that our app meets the requirements.

Focus on an infotainment system

Right now, the documentation states that supported categories for Android Automotive OS apps are focused on in-vehicle infotainment experience: Media, Navigation, Point of Interest, and Video. Compared to Android Auto, it is missing Messaging category and adds Video. Requirements are in place for all apps in general or specific categories and most of those requirements follow the principle to make the app very simple and not distract the driver.

How does it work? If you don’t have a payment option set on your account, it should ask you to add it on another device. You can’t ask a user to agree to recurring payments or purchase multiple items at once. It is not allowed even if you are not driving, and that appears to be inconsistent with the video app category. For example, it is not allowed to work at all during driving, but can display video normally when stopped.

Play Store right now presents a handful of applications, fairly easy to count all of them, most of them being in-vehicle infotainment systems: media(music and podcasts) and navigation apps. Nothing is stated about mixing categories, and none of the existing apps seems to cover more than one category.

Sensor data

Android Automotive Operating System being an integral part of the car, brings ideas about controlling features of a car, or at least reading them and reacting within an application accordingly. Emulation provides just a few options to simulate car state, ignition, speed, gear, parking brake, low fuel level, night mode, and environment sensors(temperature, pressure, etc.). There is an option to load a recording of sensor reads.

There are definitely more sensors that we are missing here that could have come in handy, and there is an extensive list of vehicle property ids to be read, with possible extensions from a car manufacturer and an option to subscribe for a callback informing us that property changed.

Managing car features

Coming to controlling a car’s features leaves us with scarce information. The first thing that came to my mind was getting all the permissions through ADB, and it brought joy when permissions like car climate change appeared, but no service or anything is provided to control those features. Documentation reveals that there is a superuser responsible for running OEM apps that are controlling e.g. air-conditioning, but for now, there is no option for a dev to make your own app that will open a window for you.

The infotainment system should be possible to make and bring all the information you can get on a car screen(worth mentioning Android Automotive Operating System should be able to control the display behind the steering wheel, that is missed in documentation as well), but do not forget that there is no such category and possibly won’t get through mandatory check.

What to look forward to in the upcoming future

After all, AAOS is here to standardize what we will see in our cars. It brings our most used applications, without plugging in the phone. We can choose our favorite navigation application and make shortcut icons for the most visited places. Our vehicle will remember where we were with our podcast and what playlist was on.

Looks like the system releases are becoming more frequent, Google is adding features that are necessary to control everything correctly from different cars. We should see it in more and more cars as this cuts costs for manufacturers and saves on developing applications. Custom skins and customizations for the screens can bring a bit of your style to your car.

Android Automotive Operating System summed up

That summary of what is going on in Automotive Android Operating System and Google Automotive Services might show there is a slight mess, both around code and documentation. That seems to be the feeling of most of the devs sharing their experiences. It is risky to develop apps without having a clear understanding of which way is the new droid going and without any board or support medium, at least to gather developers together.

That being said, it is a great time to put your app in the store and be there first. Explore what could get through the check and how far they let apps develop. We would love to get in the car at some point over a phone over an NFC spot and let it quickly adjust everything for you, with your key apps.

Do you want to start building apps for AAOS? Here is our guide to help you create AAOS Hello World.