Optimizing Current Consumption and Choosing a Battery for BLE Mesh Sensors

[cedriczz]

Hello Devzone Community,

I have been working with BLE mesh sensors and have been measuring their current consumption bellow.

I noticed that in the example you provided, the spike of current consumption is around 6mA, but in my measurements, I observe a spike of around 15mA. I'm wondering if this measurement is correct, or if there's something I'm missing.

Additionally, I noticed that a lot of current is drained during beaconing and provisioning. Once the device finds its friend, the radio turns off and optimizes battery consumption. I'm wondering if there is any way to optimize the current consumption during beaconing and provisioning, or if there are any best practices to follow in this regard.

We are currently designing a board and need to decide what kind of battery to use. We plan to use the battery cell CR2450, but I'm not sure if this battery will be sufficient. Can anyone provide recommendations on the type of battery to use for BLE mesh sensors, 

Thank you for your help.

Cedric

[Simonr]

Hi

I noticed that in the example you provided, the spike of current consumption is around 6mA, but in my measurements, I observe a spike of around 15mA.

Can you share some more details on how you're measuring current on your end? What are you measuring on exactly? Development kits or some custom design prototypes? The current spike of up to 15mA you're seeing could also be a phantom spike which we have seen before with the PPK2, as the level shifters on it have a hard time to adjust in sudden current spikes where it switches between regulators for example. These are easily spotted if you zoom in on the measurements.

Here is an example comparing a Keysight power analyzer and the PPK2. These spikes don't affect the average current consumption, as they are incredibly short, but will mess up the max current spikes. You will just have to find the actual maximum manually in this case.

Keysight measurement:

PPK2:

Hopefully these will be addressed and mitigated in a future FW update from our side, but we haven't been able to do so yet.

Best regards,

Simon