How to control WS2812B LEDs on nrf54 via SPI?

RE: How to control WS2812B LEDs on nrf54 via SPI?

ilockit_CFR — Thu, 05 Feb 2026 10:42:58 GMT

Hi,

thanks for the verification. I soldered the LED pin to another GPIO and now the LEDs are working.

Thanks for your help.

RE: How to control WS2812B LEDs on nrf54 via SPI?

Simonr — Thu, 05 Feb 2026 10:03:13 GMT

You're absolutely right Christian. The pins on P2 have some dedicated uses, where only P2.02 and P2.08 can be assigned as SDO lines for SPI00, while P2.04 is an SDI only for the SPI peripheral. I apologize for missing that in my initial replies, but on P2 you are indeed somewhat restricted to what peripherals can use the pins for.

Best regards,

Simon

RE: How to control WS2812B LEDs on nrf54 via SPI?

ilockit_CFR — Thu, 05 Feb 2026 06:44:19 GMT

Hi,

I just checked the pinplanner for the NRF54L15 QFN-48 and saw, that I can just assign P2.02 and P2.08 to the SDO line of SPI00. If that is true, then it should be clear, why there is no SPI output on P2.04, right?

Best regards

Christian

RE: How to control WS2812B LEDs on nrf54 via SPI?

ilockit_CFR — Wed, 04 Feb 2026 14:19:03 GMT

Hi,

it's configured as you can see in the initial post, except that the clock pin is configured to an unused pin at the moment.

spi00_default: spi00_default {
        group1 {
                psels = <NRF_PSEL_DISCONNECTED(SPIM_MISO)>,
					<NRF_PSEL(SPIM_MOSI, 2, 4)>,
					<NRF_PSEL(SPIM_SCK, 2, 1)>;
        };
	};

    spi00_sleep: spi00_sleep {
        group1 {
                psels = <NRF_PSEL(SPIM_SCK, 2, 1)>,
					<NRF_PSEL(SPIM_MOSI, 2, 4)>,
					<NRF_PSEL_DISCONNECTED(SPIM_MISO)>;
                        low-power-enable;
        };
	};

The method device_is_ready(led_strip) returns true.

I just testet the spi without the led_strip driver and the result was the same. The output pin doesn't shows any data.

I also checked the zephyr.dts file and I couldn't see a duplicate mapping of the pin.

Do you have any suggestions what to check next?

Best regards,

Christian

RE: How to control WS2812B LEDs on nrf54 via SPI?

Turbo J — Wed, 04 Feb 2026 12:34:03 GMT

Triple check that its not mapped elsewhere in the DTS - which you can check in the build/zephyr (sub)folder. It may have pulled something in you were not aware of.

RE: How to control WS2812B LEDs on nrf54 via SPI?

Simonr — Wed, 04 Feb 2026 11:44:16 GMT

Can you share how the SPI is set up in the devicetree now? Please follow how our SPI samples have the SPI set up in the devicetree.

Best regards,

Simon

RE: How to control WS2812B LEDs on nrf54 via SPI?

ilockit_CFR — Tue, 03 Feb 2026 13:42:48 GMT

Hi,

I'm using a custom board, where only P2.04 is connected to the LED DI interface.

RE: How to control WS2812B LEDs on nrf54 via SPI?

Simonr — Tue, 03 Feb 2026 13:28:27 GMT

Pins P2.00-P2.05 are by default connected to the external memory interface on the nRF54L15 DK, so in order to configure these to output onto the P2 header you need to open the nRF Connect for Desktop Board Configurator app to disable the external memory routing to these pins so that they go to the P2 header instead.

Best regards,

Simon

RE: How to control WS2812B LEDs on nrf54 via SPI?

ilockit_CFR — Tue, 03 Feb 2026 11:46:13 GMT

I tried to connect SCK to pin 12 (2.01) with no other result. There's also no clock signal at that pin visible. Seems that the SPI is not running properly.

RE: How to control WS2812B LEDs on nrf54 via SPI?

Turbo J — Tue, 03 Feb 2026 11:05:41 GMT

Search this forum: SPIM won't work with SCK disconnected. We had this problem a little while ago.