How to properly organize data transfer via Bluetooth?

Question

Electronics

Good day everyone!
There is a board with a counter. It transmits data via BLE to the phone. But if you organize a continuous transmission of information, then the battery lasts for a very short time. There is an idea to make a transmission every 3-5 minutes. But then how will the user know when to turn on the app in order to get this information?
Or maybe there is some other possibility to transmit information via BLE and not spend a lot of energy on it?

Answer 1

The receive and transmit slots of the master and slave devices (master and peripheral in Bluetooth Smart terminology) are synchronized. To do this, most popular chips require the connection of an external clock quartz. Sometimes it is possible without it, but then consumption increases.
That is, your device will not be in reception or transmission all the time, but will get in touch at predetermined time intervals.

Answer 2

The user may be told to run the application (or the application will automatically accept the data). To do this, the application must subscribe to a change in the value of the corresponding characteristic. To better understand what we are talking about, NordicSemiconductor has an example - nRF Beacon - there is a firmware for debugging them and a free smartphone application. When you move to the next zone from the beacon, a notification pops up on the screen.