How to save BLE peripheral power after connected with nrf52840

[kienasv]

Hi,

I am using coded BLE to connect two board using nrf52840. I just let bluetooth to run, then measure power consumption of the peripheral board by measuring the current:

- before enable bluetooth: ~9.8 uA

- broadcast: ~110 uA

- after connected: (121 - 165) uA

In this test, after connected, I stop broadcast, then do nothing. It means there is NOT data transfer between collector-peripheral.

I think the power consumption after connected is high due to the layer link for maintaining active connection. But do you know how to configure to reduce this power consumption after connected? In my application, the peripheral only send 18 bytes of data every 1 hour.

Thank you.

[Jared]

Hi,

Our Online Power Profiler should give you a roughly estimate of what you could expect. The current is dependent on several factors such as supply voltage, connection interval, DCDC configuration etc.

Also, check this blog post. 

regards

Jared

[kienasv]

Hi Jared,

Thank you for your reply.

I try to change connection interval to 4s but not success. When I turn off peripheral, the collector know connection disconnected almost immediately. I think that it should know the disconnected state after 4s of timeout.

Can you tell me how to change connection interval to 4s?

Thanks,

[Jared]

Hi,

If you're using a SDK example, then it should be enough to just adjust MIN_CONN_INTERVAL and MAX_CONN_INTERVAL. Note that the Central is the one that does the final decision on what the connection interval should be. 

Try verifying it by using the nRF sniffer

regards

Jared