Power Usage when connected to nRF Connect Android App

[Gary T]

Hi

I am testing a thermometer peripheral using the nRF52840DK. It is advertising using BT LE Coded (BT_LE_ADV_OPT_CODED) with an advertising frequency of 3 seconds.

When it is advertising it is using ~20µA of power. When I connect to the peripheral using the nRF Connect App on my Android phone the power usage of the peripheral goes up to ~235µA.

I believe the connection parameters are controlled by the "Central" which in this case would be my phone. Is this correct?

Using my PPK2 I can see that there is power usage every 45ms.

Is there any way to control the settings on the nRF Connect App to lower the power usage (perhaps by changing the 45ms communication interval)?

I also have another question related to the connection timeout for the nRF Connect Android App.

If I set my advertising interval on my peripheral to 2 seconds the app connects reliably. If I set it to 3 seconds then sometimes it connects but sometimes it times out. If I set it to 5 seconds then it never seems to connect. Is there a specific connection timeout in the app? Is there a way for me to adjust this?

Thanks for your help.

Regards,

Gary

[Gary T]

Hi Kazi

Thank you for your feedback. 

I was successful in changing the connection interval from the default (~45ms to around ~150ms) by adding the CONFIG's you mention below to the PRJ.conf file.

Interestingly, if I set the MAX_INT beyond 160 then I get a compile error. 

For example, if I use the exact values you provide below, it doesn't work.

According to the docs it seems I should be able to set this anywhere from 6 to 3200.

Any ideas on what's causing this?

Thankfully, setting to 160 has dropped the power usage while connected from ~235µA to ~60µA which is good enough for me (although I would like it lower).

Thanks for your help.

Regards,

Gary

[Kazi Afroza Sultana]

Hello Gary,

Is the preferred time is 1/4 of the supervision timeout in your configuration?

This is another requirement for preferred connection interval. 

Thanks.

Best Regards,

Kazi Afroza Sultana