NRF5340, WS2812, I2S

Question

Hello.

I'm trying to use WS2812 leds with I2S. I'm using two boards for testing: an NRF5340DK and my board based on the HOLYIOT-21069-5340 module.

I'm using a zephyr/samples/drivers/led/led_strip as an example.

I need the control signal to be on P1.00. I'm trying it with the NRF5340DK board first.

Here's my overlay file:

#include <zephyr/dt-bindings/led/led.h>

/ {
    aliases {
        ledstrip = &ledstrip;
    };
};

&pinctrl {
    i2s0_default_alt: i2s0_default_alt {
		group1 {
			psels = <NRF_PSEL(I2S_SCK_M, 1, 15)>,
				<NRF_PSEL(I2S_LRCK_M, 1, 12)>,
				<NRF_PSEL(I2S_SDOUT, 1, 0)>; // Output pin to LED strip
		};
    };
};

&i2s0 {
    status = "okay";
    pinctrl-0 = <&i2s0_default_alt>;
    pinctrl-names = "default";

	ledstrip: ws2812@0 {
		compatible = "worldsemi,ws2812-i2s";

		reg = <0>;
		chain-length = <2>; /* arbitrary; change at will */
		color-mapping = <LED_COLOR_ID_GREEN
					LED_COLOR_ID_RED
					LED_COLOR_ID_BLUE>;
		reset-delay = <500>;
	};
};

&uart0 {
    status = "disabled";
};

&i2c1 {
    status = "disabled";
};

&spi4 {
    status = "disabled";
};

&pwm0 {
    status = "disabled";
};

&qspi {
    status = "disabled";
};

&usbd {
    status = "disabled";
};

&usbreg {
    status = "disabled";
};

If I use pin P1.00, nothing works — the pin stays high all the time. If I use P1.01 or P1.13, everything works.

P1.00 is listed in the description as a "General purpose I/O." Nothing seems to be connected to it on the board either. Why can't I use it?

The second problem occurs when I try to use my board. The board is based on a HOLYIOT-21069-5340 module with nRF5340 QKAA.

I use the exact same code without rebuilding it.

I'm just doing a "west flash," but instead of a NRF5340DK board, I'm connecting my HOLYIOT-21069-5340 module. And for some reason, the driver stops working, and I get the following messages in debug:

[00:00:00.000,213] <dbg> ws2812_i2s: ws2812_i2s_init: Word clock: freq 100000 Hz period 10 us
*** Booting Zephyr OS build v4.3.0-7395-g768095e06b41 ***
[00:00:00.000,274] <inf> main: Found LED strip device ws2812@0
[00:00:00.000,274] <inf> main: Displaying pattern on strip
[00:00:01.001,403] <err> i2s_nrfx: Cannot write in state: 3
[00:00:01.001,434] <err> ws2812_i2s: Failed to write data: -5
[00:00:01.001,434] <err> main: couldn't update strip: -5
[00:00:02.001,586] <err> i2s_nrfx: Cannot write in state: 3
[00:00:02.001,586] <err> ws2812_i2s: Failed to write data: -5
[00:00:02.001,586] <err> main: couldn't update strip: -5

My prj.conf:

CONFIG_LOG=y
CONFIG_LED_STRIP=y
CONFIG_LED_STRIP_LOG_LEVEL_DBG=y

CONFIG_SPI=y
CONFIG_I2S=y
CONFIG_WS2812_STRIP_I2S=y

CONFIG_USE_SEGGER_RTT=y
CONFIG_LOG_BACKEND_RTT=y
CONFIG_LOG_BACKEND_UART=n

I do it simply:

1. Build: west build -b nrf5340dk/nrf5340/cpuapp --sysbuild

2. Flash: west flash

3. Debug output: west rtt