nRF54L15-DK, disable uart20, P1.14 can't output waveform

James168 1 day ago

Hi,

NCS v3.4.0, based on bluetooth mesh light_ctrl sample

nRF54L15-DK

I want to use P1.06, P1.07 and P1.14 as GPIO to toggle waveform, so I modify light_ctrl sample to add timer for output toggle.

When uart20 is enabled, the P1.14 can output toggle waveform as expected,

but when disabled uart20 in overlay file, the P1.14 has no output.

P1.14 is not uart pins, it should not be affected by uart20 configuration?

I attached the project for reference.

light_ctrl_v340_P114_test.7z

0 Simon D-M 1 day ago

Hi,

Actually your issue is not that the LED doesn't blink. It is that your program doesn't even start with UART20 disabled.

The reason is that you are outputting logs in the console, and that the console is still linked to the UART20 which is disabled.

It depends on why you want to remove the UART20 but a way to handle this is to reroute the console through another UART. For example routing it through UART30:

/* For more help, browse the devicetree documentation at https://docs.zephyrproject.org/latest/build/dts/index.html
 * You can also visit the nRF DeviceTree extension documentation at https://docs.nordicsemi.com/bundle/nrf-connect-vscode/page/guides/ncs_configure_app.html#devicetree-support-in-the-extension
 */

/{
    chosen {
		zephyr,console = &uart30;
	};
};

&uart30 {
    status = "okay";
};


/* Disable uart20 (Serial Port 1: P1.04/P1.05/P1.06/P1.07) to free P1.06 */

&uart20 {
    status = "disabled";
    /* status = "okay"; */
};

/* Enable GPIO1 for LED control with proper clock configuration */
&gpio1 {
    status = "okay";
};

If this fix doesn't really suit your needs, feel free to reach out again.

Best regards,

Simon