BLE power consumption using CORDIO stack too high

[sagrebin]

Description of defect

I've cloned the mbed-os-example-ble repo and removed the LED blinking code and the print statements. When I run the application on my dev board and use nordics power profiler I get an average of 1mA when advertising (advertising interval: 2 sec).
I did the same with the with the deprecated sample BLE_BatteryLevel which uses nordics soft device and I get around 20uA when advertising.
I use a custom dev board with the ublox NINA-B112 module, there are no other components on the board which could consume power.

Target(s) affected by this defect ?

NRF52_DK

Toolchain(s) (name and version) displaying this defect ?

GCC_ARM

What version of Mbed-os are you using (tag or sha) ?

a4738fa

What version(s) of tools are you using. List all that apply (E.g. mbed-cli)

mbed-cli 1.10.0

How is this defect reproduced ?

See the description above

[40Grit]

If debugging with an .svd loaded,

are you able to confirm which peripherals are enabled and running between the two examples?

Also would be interesting to see the clock configurations between the two.

[40Grit]

Mistyped .svd above.

[yogeshk19]

@40Grit We are seeing similar power consumption and at times even higher than 1ma during advertisements. One of the other issues, had listed out disabling the cryptocell and here is what the mbed_app.json looks like. Ours is a custom board with NRF52840 BLE module. We are using Cordio API without the Nordic Softdevice.

{ "target_overrides": { "NRF52840_DK": { "target.features_add": ["BLE"], "target.extra_labels_add": ["CORDIO", "CORDIO_LL", "SOFTDEVICE_NONE", "NORDIC_CORDIO"], "target.features_remove": ["CRYPTOCELL310"], "target.macros_remove": ["MBEDTLS_CONFIG_HW_SUPPORT"], "target.extra_labels_remove": ["SOFTDEVICE_COMMON", "SOFTDEVICE_S140_FULL", "NORDIC_SOFTDEVICE"], "platform.stdio-baud-rate": 115200, "platform.default-serial-baud-rate": 115200, "target.console-uart-flow-control": null } } }
Thanks,
Yogesh

[40Grit]

My questions above are wondering what soft device does with the clocks/peripherals/radio settings in order have significantly lower power consumption than cordio stack.

[0xc0170]

My questions above are wondering what soft device does with the clocks/peripherals/radio settings in order have significantly lower power consumption than cordio stack.

cc @ARMmbed/mbed-os-pan

[40Grit]

@sagrebin , @yogeshk19 To provide further clarity to my vague posts above.

Are either of you able to dump the peripheral registers when using softdevice and when using cordio?

The diff between the two dumps could provide some insight since the softdevice sources are closed.

[yogeshk19]

@40Grit Sorry I haven't had a chance to dump the peripheral registers. I am planning on re-running my power draw tests again after the next mbed-os release which is supposed to have updates to hci driver i believe. I am not planning on using the softdevice at this point, only the Cordio API as is.

[sagrebin]

@40Grit I was hoping that with the arrival of nordics sdk 15 it would be fixed by unfortunately its not. I've dumped the registers:
cordio: https://pastebin.com/i1q4T08m
nordic SD: https://pastebin.com/47XEkrBh

[pan-]

From the diff it looks like the LFCLK is synthesized from the HFCLK when Cordio is used. That might be one of the cause of the high power consumption.

[sagrebin]

Indeed, for some reason the NRF_LF_CLK_SRC is set to CLOCK_LFCLKSRC_SRC_Synth in NRFCordioHCIDriver.cpp
#if MBED_CONF_NORDIC_NRF_LF_CLOCK_SRC == NRF_LF_SRC_SYNTH #define NRF_LF_CLK_SRC CLOCK_LFCLKSRC_SRC_Synth
But what I don't get is why MBED_CONF_NORDIC_NRF_LF_CLOCK_SRC is set to NRF_LF_SRC_SYNTH. Every definition I can find is set to NRF_LF_SRC_XTAL

[40Grit]

@AGlass0fMilk

@sagrebin : so you see NRF_LF_CLK_SRC set to NRF_LF_SRC_XTAL in mbed_config.h ?