I want to double check current draw in the nRF9160 low power modes and need some help in making sure I know how to do so.
I plan to use an oscilloscope for measuring current at this time. I understand that measuring low currents might be difficult so may need to switch to an ammeter. I'm doing this on the nRF9160 DK 0.8.5 version.
I think the power modes I need to measure are System ON Idle, and System OFF. I haven't had much luck finding support in the SDK on getting into the modes and am not sure if there are samples that might help. I know the spec for the 9160 shows current draw in these modes and registers controlling the power management.
For getting into System ON Idle, I know that is entered when no application is running and when no modem transmissions are taking place. Correct? Is this the same mode that the 9160 would be in when in PSM sleep? From other DevZone articles I gather that I would need to first turn the modem off; is this best accomplished via an AT command, using the AT Command Interface library? For putting into idle, is there SDK support for that? Sample code?
For System OFF, is there SDK support to get into that mode and any sample code?
I have read that there are times that going to System OFF to get lowest current draw may not make the most sense as the device has to re-register on the network (?) and that takes significant current. In those cases PSM makes more sense. How does one best go about doing the analysis to determine which is the best approach?
Thank you,
Erik
