RE: NRF54L15: Can't use any UART other than UART20???

Vidar Berg — Tue, 25 Nov 2025 13:38:20 GMT

Hello Alex,

If you are using the nRF54l15DK as your build target there are some default assignments. For instance, SPIM00 (shared instance with UARTE00) is assigned to the onboard SPI flash:

To use this serial interface for UARTE instead you would need to disable the SPI00 node in the devictree and use the board configurator app to re-route the IO pins from the SPI flash to the pin headers. Here is an example of a devictree overlay that enables UART00 and UART30:

nrf54l15dk_nrf54l15_cpuapp.overlay

&spi00 {
    status = "disabled";
};

// High speed UART intstance
&uart00 {
    status = "okay";
    current-speed = <115200>;
	pinctrl-0 = <&uart00_default>;
	pinctrl-1 = <&uart00_sleep>;
    pinctrl-names = "default", "sleep";
};


&uart30 {
    status = "okay";
};


&pinctrl {
    	uart00_default: uart00_default {
		group1 {
			psels = <NRF_PSEL(UART_TX, 2, 1)>;
		};
        group2 { 
			psels = <NRF_PSEL(UART_RX, 2, 2)>;
            bias-pull-up;
		};
            
	};

	uart00_sleep: uart00_sleep {
		group1 {
			psels = <NRF_PSEL(UART_TX, 2, 1)>,
				<NRF_PSEL(UART_RX, 2, 2)>;
				low-power-enable;
		};
	};
};

Best regards,

Vidar