Google's updated developer preview of Android Things adopts the latest version of Android, the latest version of Google Play Services, and adds new APIs for managing Bluetooth performance. Google also took pains to address developer feedback in this release.
Google has made Android Things Developer Preview 7 available to developers. Android Things is Google's platform for creating Internet of Things devices, apps, and services. It also lets developers put TensorFlow to use for processing audio and video. This latest preview takes several significant steps forward, and tosses in new APIs for good measure.
Let's address the new APIs first. Android smartphones and tablets rely on the settings menu for discovery, pairing, and connecting to other Bluetooth devices. IoT devices don't necessarily have that luxury, and these same functions need to be handle programmatically. Android Things Developer Preview 7 adds the BluetoothConnectionManager API to the stack. This API lets apps take control of the pairing and connection process, according to Google. In other words, the process is somewhat more automated.
Google has detailed the steps needed to complete this process in documentation here. Separate APIs are required to configure device attributes, pair with remote devices, connect with remote devices, and set permissions. Once these are mastered, developers should be able to ease the process of getting their devices and apps talking to one another.
Other API changes abound. In Preview 7, for example, Google renamed many of the existing Android Things API classes to "provide a more consistent developer experience across the entire surface." Testability of Android Things apps should be improved thanks to the updated Peripheral I/O API, which exposes interfaces instead of abstract classes. Preview 7 adds support for the MidiManager API, which lets developers build virtual MIDI devices to interface with external MIDI controllers. Google said it addresses these tools primarily due to user feedback.
Android Things Developer Preview 7 makes the important upgrade to Android 8.1 Oreo, putting it in line with the most recent build of Android available. It also adopts Google Play Services 11.8.0, which includes support for Firebase, location, Google Pay/Wallet, and wearables.
As for dev-facing tools, the Android Things Console packs in some new features. For example, new product models will let developers create multiple software versions of the same hardware product for testing purposes. Through product sharing, developers can grant additional user accounts access to view and manage models/builds of any given project. New analytics let developers view metrics on device activations and statistics. And update channels make it simple to deploy software builds to groups of devices for beta testing.
Last, Android Things Developer Preview 7 has new sample updates available in Kotlin. Google is offering a Kotlin version of Android Things samples so developers can test in Kotlin and Java at the same time. Further, Google migrated the TensorFlow Image Classifier sample app to the TensorFlow Lite library. Google claims this reduces the size of models by over 90%.
Developer Preview 7 is available on the NXP i.MX7D, NXP i.MX6UL, and Raspberry Pi 3 development boards.