RE: SHELL_BACKEND_RTT increased current consumption when buffer fills up

Einar Thorsrud — Mon, 12 Aug 2024 13:39:22 GMT

Hi,

I see the same as you, and I have not been able to get to the bottom of this yet, but I will continue to look into it.

Regardign CONFIG_SHELL_RTT_RX_POLL_PERIOD that is a good comment, but I suspect a lower value is better as default as RTT is typically only used for debugging and not in production code or code where you are measuring current consumption. So responsiveness is probably more important than saving some milli amps.

RE: SHELL_BACKEND_RTT increased current consumption when buffer fills up

lev — Mon, 12 Aug 2024 10:15:04 GMT

As a side note:
CONFIG_SHELL_RTT_RX_POLL_PERIOD=1000 (ms) is critical for low power. I think it would make sense to maybe have the default higher interval if CONFIG_PM_DEVICE=y? Or have it documented under achieving low power consumption.

Without this config the current is ~32uA instead of ~4 uA.