Minimum current nrf52832 on System ON mode

[Pezza8692]

Hi I am trying to reduce the power consumption of the badge of my company as much as I can. We use a proprietary radio protocol on the nrf52832.

I'm currently developing with the SDK 13 through using Keil on Windows.

The badge has only the nordic and an Linear Technology accelerometer. I was able to reduce the power consumption to a decent number (35uA with a 300ms broadcasting rate). I am trying to go lower than that for a "storage status" when devices are supposed to sit in storage for a long time. 

Reducing the ping rate I am able to get closer to 15/20uA average current consumption, and I realized that I cannot go lower than that considering that when the system is Idle I can't go lower than around 15uA. (I am using the nordic power profiler to get these numbers). I pretty much turned off the accelerometer, made sure than I don't have any debug mode active, using app_timer to wake up the system (so I should be using RTC1). I also turned on the level 3 and time optimization in the Keil compilation.

Is there anything else I can do? Am I missing something?

[hmolesworth]

15uA seems very high. In System On you can power down unused RAM, which in the scenario described above could be pretty much most of the RAM. That's 20nA per 4kByte. Low Power mode is also lower power than Constant Latency mode. Other savings depend on pin settings and external connections to those, and being sure all unused internal peripherals are safely off. Is the accelerometer powered by an io pin? I like to capture all the pin settings when going to sleep and coming out of sleep in case something is amiss, or unexpected.