NRF52840 indication power consumption

[joel-sc]

Hello,

In order to improve the connection reliability of our device, I'm planning to migrate a custom characteristic from the notification property to the indication and I'm wonder what is the impact in term of power consumption.

Currently our payload (247 bytes) is sent through a notification value. The connection interval is generally 24 ms.

Tell me if more information is needed.

Best

Joël

[Naeem Maroof]

Hi

Just note that the notifications are unacknowledged, while indications are acknowledged, and thus notifications are faster but less reliable.

This might have an impact on the power consumption, and would also depend how many acknowledgements are received (to be received) for the same payload. 

May I suggest you to check the power dissipation for both of the use-cases by measuring using PPK2 or any other hardware that you may like.

[joel-sc]

Thanks for the suggestion. I've tried but I don't think my setup is able to capture this.

Theoretically the time to transmit an ack packet is 40 us (80 bit in PHY2). The radio needs to listen (RX) during this time and thus consume ~10 mA (+8dBm). I think I can use this.

I've used the online power profiler to assume those numbers.

devzone.nordicsemi.com/.../online-power-profiler-for-bluetooth-le