Current consumption estimation for BLE mesh

[jacob.george]

Hi,
I am trying to implement a BLE mesh using nrf52840. How can I estimate the current consumption?
I checked with the online power profiler tool, but it does not support BLE mesh.

[Kenneth]

Hello,

It depends on the node. For low power nodes the BLE online profiler should be pretty accurate, however for normal relay nodes it will stay in receive mode the entire time, likely around ~7mA.

Kenneth

[jacob.george]

Hi Kenneth,

Thank you for your support.

I tried to calculate the current consumption due to Tx and Rx for a Relay node. Can you please check whether it is correct or not?

The assumptions are as follows,

nrf52840 working voltage-3v,

DCDC regulator ON,

LF clock - Internal RC,

TX power 8dBm,

Tx payload 16bytes. 

Tx interval -5s

(For the mesh, I selected Max_backoff time as 10sec. So if the Tx interval is random with a max value of 10s,  for a long period I assume the Tx interval to be 5s on an avg.) 

Rx is assumed to be always on.

For the above conditions the Tx event charge = 19.542uC (duration-4us)

(This is from the online power profiler tool for  nrf52840 for a role of Advertising(connectable) --since mesh option is not in the tool I think this role is suitable.)

Rx event charge for 5s is = IRADIO_RX0 * (5000-Tx event time)mS = 31300uC

(IRADIO_RX0 is the Rx current from the data sheet)

Total charge= 31319.542uC (6.26mA for  5sec)

Please correct me if iam wrong..