RE: Excessive power consumption in bootloader_secure_ble?

Fredrik — Wed, 01 Aug 2018 09:35:48 GMT

Hi Bjørn,

Thanks for your detailed answer. I am indeed using SDK 14.2.0. It's good to hear that the bootloader has been power optimized in SDK 15, and I think we will migrate.

RE: Excessive power consumption in bootloader_secure_ble?

bjorn-spockeli — Thu, 26 Jul 2018 15:25:04 GMT

Hi Fredrik,

Which SDK version are you using? Judging from the SoftDevice version, S132 v5.0.0 it would seem that its SDK v14.x.x. I did a quick power profiling of the bootloader alone with the SoftDevice using the Nordic PPK and the result is an average current consumption of 5mA. The Secure Bootloader projects from SDK v12.x.x through SDK v14.x.x were never power optimized as they only ran on the device for a very limited time , which explains the high average currents.

The Secure Bootloader from SDK 15 on the other hand has been optimized both for power efficiancy as well as throughput( thats another story). The average current used by the SDK v15.0.0 BL is about 114uA, which is a a vast improvement from SDK v14.0.0

I also compiled the ble_app_template project from SDK 15 and generated the settings page and flashed both to the nRF52 DK with the SDK 15 Bootloader

The first spike coincides with the power being applied and the second is the application starting up. What kind of average currents are you seeing in your measurements? I would anyway recommend moving to the latest SDK version.

Best regards

Bjørn