We recently published some developer tutorials on how to add SmartWatch 2 (SW2) support to the first SmartWatch (MN2) extensions and how to create a SmartWatch 2 app extension. Now, we’d like to bring you additional information on best practices for your SmartWatch 2 app development, covering topics that range from how much data your app extension sends to recommended resolutions to display considerations. Keeping these five important tips in mind during your development can help minimise potential bugs, make your app extension more compatible with the new SmartWatch 2 features, and ensure overall that your SmartWatch 2 app will work smoothly.
Whether you’re starting from scratch or you’re in mid-development, here are a few tips to keep in mind when working with the new version of the Sony Add-on SDK. This is an add-on for the standard Android SDK that gathers a number of Sony APIs used for app development, including the APIs used for Smart Accessories, called Smart Extension APIs.
#1 – Don’t send too much data to the watch
When developing for a wearable device, like the SmartWatch 2, it is extra important to consider battery consumption and processing power. For example, sending several full screen images per second will likely create an ever-growing queue of data, and the display on the watch will fall further and further behind. In addition, if the SmartWatch gets too frequent screen updates, it will cause the battery to drain unnecessarily fast.
#2 – Use a resolution of 220 x 176 pixels
The screen of the SmartWatch 2 has a resolution of 220 x 176 pixels, and the entire screen is available to an extension that uses the Control API. You can provide crisper graphics if your extension draws its control using the resolution of 220 x 176 pixels. Also, the extension icon used in the home screen of SmartWatch 2 is 48 x 48 pixels. When registering, the extension can provide this icon using the new constant defined by ExtensionColumns.EXTENSION_48PX_ICON_URI. Finally, try not to place buttons or icons too close to the edge of the screen, as the touch isn’t as sensitive closer to the edges.
#3 – Tap touch and swipe motions can control the displayA SmartWatch 2 extension that uses the Control API is in control of the entire display. For a Smart Extension app that uses the Control API, the SmartWatch supports both tap touch (through CONTROL_TOUCH_EVENT_INTENT, CONTROL_OBJECT_CLICK_EVENT_INTENT, CONTROL_LIST_ITEM_CLICK_INTENT or ControlExtension.onTouch()) and swipe motions (through CONTROL_SWIPE_EVENT_INTENT or ControlExtension.onSwipe()).
#4 – Publishing on Google Play™
If you create a SmartWatch 2 extension, you can get a lot of great exposure by making your app show up when end users are searching for compatible apps through Smart Connect (technically from the host application, but in the Smart Connect user interface). From here, users can find all compatible apps filtered from Google Play™.
To make your app show up in the pre-defined Google Play™ search, just make sure the Google Play™ description for your app includes the following string (we recommend at the bottom, on its own line):
Smart Connect extension for SmartWatch 2
#5 – Additional general considerations
Some additional considerations that you should further keep in mind include:
- An extension using the Control API may only have one simultaneously visible ListView or Gallery.
- SmartWatch 2 can store and show up to 30 events for an extension.
- When drawing on SmartWatch 2 using a layout, the maximum number of views that can be shown simultaneously on the screen is 50.
- The vibrator on SmartWatch 2 has the following specifications: a minimum runtime of approximately 250 ms, a run-down time of 250 ms, and a maximum continuous time of six seconds. After six seconds, the vibrator will automatically turn off to conserve battery.
We hope to see your SmartWatch 2 extension on Google Play™ soon. If you have any questions, feel free to drop us a line in the Comments field below, and we’ll get back with an answer as soon as we can.
- Read our recent Sony Add-on SDK blog post.
- Check out our tutorial on How to add SmartWatch 2 support to original SmartWatch extension.
- Learn more about the features of the latest Sony Add-on SDK.
- Find out all about the Smart Extension APIs and how to create apps for Sony accessories, including Sony SmartWatch 2 (SW2) and the original Sony SmartWatch (MN2).
- Get promotion for your SmartWatch 2 extension through the Stand out from the crowd campaign.