Hi all,
I'm currently developing a product with the nRF52840 and FreeRTOS using SDK 15.2 where Bluetooth will be needed eventually, but not yet. I originally based the project on the ble_app_hrs_freertos demo, and just figured if I didn't initialize or touch the softdevice that it wouldn't do anything, but I was never able to get the power consumption down very low (maybe 280uA). My guess is that I need to do some basic initialization of the softdevice to get it to be present, but not interfere and increase power consumption.
When I do get ready to start turning Bluetooth on, my plan is to just turn it on when the user hits a certain button and leave it on for 5 minutes or so to let the user interact with the device before returning to a very low power state.
For now, I've started a new project with no softdevice based on blinky_rtc_freertos that behaves pretty well for power consumption. I'm able to get the power down to <20uA on average. When fully asleep it drops down to maybe 3uA.
I found a promising thread about getting a Bluetooth device to go to sleep HERE, but the updated port_cmsis_systick.c file from that ticket is different enough from the one included with SDK 15.2 that I can't tell if the fixes have been incorporated into the newer SDK or not.
Specific questions:
1) What do I need to do to initialize the softdevice into a fully off state so that it doesn't cause any increased power consumption
2) Any advice on how to turn the softdevice on for awhile, and then turn it back off so that it will return to that fully off no-additional-power-consumption state?
Thanks,
Glen