nRF54L15 (NCS 3.2): Excessive current consumption on UART30 when CONFIG_LOG_MODE_IMMEDIATE=n

RE: nRF54L15 (NCS 3.2): Excessive current consumption on UART30 when CONFIG_LOG_MODE_IMMEDIATE=n

Kazi Afroza Sultana — Thu, 30 Apr 2026 14:23:03 GMT

Hello,

I have read a previous case (+) How to use low-power UART demos other than lpuart - Nordic Q&A - Nordic DevZone - Nordic DevZone waht you can look at.

Besides setting the CONFIG_SERIAL=n in the prj.conf file you can add the following code

#include <zephyr/pm/device.h>
static const struct device* uart_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_console));
err = pm_device_action_run(uart_dev, PM_DEVICE_ACTION_SUSPEND);

RE: nRF54L15 (NCS 3.2): Excessive current consumption on UART30 when CONFIG_LOG_MODE_IMMEDIATE=n

xht1987 — Fri, 24 Apr 2026 03:12:33 GMT

I've tried it, but it still doesn't work.

RE: nRF54L15 (NCS 3.2): Excessive current consumption on UART30 when CONFIG_LOG_MODE_IMMEDIATE=n

Kazi Afroza Sultana — Tue, 21 Apr 2026 13:11:03 GMT

Hello,

Your observation and approach are right in terms of lowering the power consumption.

Can you try the following config and try with UART30 again?

CONFIG_LOG=y
CONFIG_LOG_MODE_DEFERRED=y
CONFIG_LOG_BACKEND_UART=y
CONFIG_LOG_BACKEND_UART_ASYNC=y
CONFIG_UART_ASYNC_API=y
CONFIG_PM_DEVICE_RUNTIME=y
CONFIG_PM_DEVICE=y

RE: nRF54L15 (NCS 3.2): Excessive current consumption on UART30 when CONFIG_LOG_MODE_IMMEDIATE=n

xht1987 — Tue, 21 Apr 2026 05:21:10 GMT

my custom board

RE: nRF54L15 (NCS 3.2): Excessive current consumption on UART30 when CONFIG_LOG_MODE_IMMEDIATE=n

Kazi Afroza Sultana — Mon, 20 Apr 2026 13:06:02 GMT

Hello,

Is it on nRF54L15 dk or custom board?