How can I make a wearable Android app set off the alarm on the handheld?

Question

I created a very simple android wearable app for a watch that uses the accelerometer sensor. I have the watch connected to a mobile device over bluetooth. When a certain value is detected by the accelerometer, I'd like for the phone to sound an alarm. I'm quite new to Android Programming, but I've been trying to read the documentation. I was looking at the Notification documentation, but I can't seem to figure out which data layer functionality I need. What I am trying to accomplish seems very simple to me: Run the app on the watch, detect a value, sound alarm on handheld. The documentation is suggesting a more complicated process. Am I overthinking this?

Answer 1

Once you detect the event you are interested in on the wear side, you need to send a message to your phone app (using MessageApi ) and then you need to have an implementation of WearableListenerService on your phone app that can capture that message and trigger whatever you are interested in.

To send a message to your phone, you should use the CapabilityApi ; basically your phone app should declare that it provides, say, "alarm_capability" (or whatever you want to call it) and then your wear, upon detecting the appropriate event, can ask the framework for the connected nodes that provide "alarm_capability". Framework will return the node corresponding to your phone and then you can simply use the MessageApi to send a message to that node.

All of this is pretty straightforward to do and there are a number of samples on our GitHub repo that accomplish similar things (for example, FindMyPhone is pretty close to what you want). You can look a those samples and also read bout the APIs and give it a try. An alternate approach is to use a library that simplifies these steps, for example you can use WearCompanionLibrary .