How to poll data from sensor using an android app nrf52 nordic

[frodyteen]

I am developing on the nRF52 boards with a capacitive sensor. I followed the tutorial in this link and created a custom service with 3 read characteristics. I am able to use the nordic connect app to read the values in those 3 characteristics continuously. I am also able to modify the nrf uart app to read those values and print it out on the phone continuously when I connect to the nrf52.

However, what I want to do now is polling data from the nrf52 when I press a button on the android app. For example, my nrf52 will be in sleep mode, then when I connect it to the phone and pressed a button, then the nrf52 will wake up and send some data over to the phone for a few seconds then nrf52 goes back to sleep again.

I'm having trouble on how to set up my application so that it will only send data when I press a button. Any suggestion on how to implement this would be appreciated it.

Thank you

[frodyteen]

Thanks a lot for your answer, I'm still trying to figure out how I am going to implement everything. So is there a way to send a signal from the phone to the nrf52 board to wake up the board?

Also, On the nrf connect app, there is a download button on the side of the read characteristic and each time I hit the download button, it will update a new value from the capcitive sensor reading. Basically, I want to implement a button like that.

On top of that button, I want the nrf52 board to read data from the capacitive sensor for a few seconds when I press the button. when the button is not pressed then the nrf52 board and the capacitive sensor should be in sleep mode.

Does this clarify more on my questions?