How to implement sound synchronization?

Question

Java

Hello.
There is a STS program: The second screen
has functionality

• Run the application with the microphone on;
• Turn on the air of the STS channel on your TV - your gadget itself synchronizes with it by sound;

I wonder how this can be implemented?
Thanks in advance.

Answer 1

apparently, it is necessary to encode a piece of data into sound, which can then be decoded on the other side, converting, for example, into a URL to go to a service on the Internet or other useful data.
For example, you can read about FSK.

Answer 2

Tasker + Plugins like extensions ok google. The battery will eat ... It's better to attach the synchronization task to another event in the same tasker, for example, time or location (neer wifi for example).