Dear colleagues!

I have this nice nRF51 sensor tag. May be you can help me to understand the limitations of this board.
I want to make wireless water tank cap opening sensor. I have another device (my own development) with bluetooth BLE interface, with external power supply which will act as receiver.

And I'd like to use nRF51 as wireless battery powered cap opening sensor. As I can understand in Aliexpress-version it is not possible (short battery life). I think I must make new firmware at least.
But is it possible to do onboard ?

1. Switch off BLE transmission but still make onboard analysis of fuel cap movement with MPU6050
2. When cap open event is detected (my MPU6050 data) - wake up BLE and start transmission.

Or may be Low power BLE mode will shut up MPU6050 transmission too and this mission is impossible?

Many thanks!