UART power consumption Zephyr NRF52833

RE: UART power consumption Zephyr NRF52833

Amanda Hsieh — Fri, 05 Aug 2022 09:55:27 GMT

Hi,

We only support nRF Connect SDK in our integration layer and we can't really help if the customer wants to use the vanilla Zephyr. That is, all the development was with nRF Connect SDK in mind, and we cannot guarantee it will work without code changes in a different context.

[quote user="sixaxix9"]If I set CONFIG_SERIAL disabled, won't this disable the UART functionality?[/quote]

Agree.

-Amanda

RE: UART power consumption Zephyr NRF52833

sixaxix9 — Wed, 27 Jul 2022 19:00:30 GMT

Hi Amanda, thank you for your answer.

Unfortunately, installing the NCS is not an option, as the code to be used has to be pulled from the Zephyr GitHub repo.

I have LOG functions in the code, so I have to set up CONFIG_LOG always enabled. If I set CONFIG_SERIAL disabled, won't this disable the UART functionality?

RE: UART power consumption Zephyr NRF52833

Amanda Hsieh — Fri, 22 Jul 2022 09:01:20 GMT

Hi,

[quote user="sixaxix9"]I am getting error -134 when trying to set the UART to state off:[/quote]

Do you install Zephyr via our NCS? If not, could you install NCS v1.9 which includes Zephyr 2.7?

[quote user="sixaxix9"]After some digging in the Zephyr power management code I found out that I should be using `pm_device_action_run`. It actually helped saving about 700uA, but we still get a baseline of 1mA instead of few uA (that we achieve with the UART disabled in the devicetree). Any pointers?[/quote]

Could you also try to set CONFIG_LOG=n and CONFIG_SERIAL=n in the prj.conf?

There is an example provided by my colleague in this thread. Could you also try that?

-Amanda

RE: UART power consumption Zephyr NRF52833

sixaxix9 — Thu, 21 Jul 2022 11:34:37 GMT

Hi Amanda, thank you for your reply :)

I am getting error -134 when trying to set the UART to state off:

error = pm_device_state_set(DEVICE_DT_GET(DT_NODELABEL(uart1)), PM_DEVICE_STATE_OFF);

Please consider that I am using Zephyr 2.7 (commit in first message) and I have changed the function names accordingly.

RE: UART power consumption Zephyr NRF52833

Amanda Hsieh — Thu, 21 Jul 2022 11:16:18 GMT

Hi,

You can use the power management API as

// Turn off UART1:

uart1 = device_get_binding(DT_LABEL(DT_NODELABEL(uart1)));

device_set_power_state(uart1, DEVICE_PM_OFF_STATE, NULL, NULL);

See this thread.

Regards,
Amanda

RE: UART power consumption Zephyr NRF52833

sixaxix9 — Thu, 21 Jul 2022 11:11:27 GMT

Update:

After some digging in the Zephyr power management code I found out that I should be using `pm_device_action_run`. It actually helped saving about 700uA, but we still get a baseline of 1mA instead of few uA (that we achieve with the UART disabled in the devicetree). Any pointers? :)

error = pm_device_action_run(DEVICE_DT_GET(DT_NODELABEL(uart1)), PM_DEVICE_ACTION_RESUME);