nrf54L15 : Unable to use UARTE00 P2.0, P2.2, P2.3, P2.4 not able to send data.

RE: nrf54L15 : Unable to use UARTE00 P2.0, P2.2, P2.3, P2.4 not able to send data.

Kenneth — Sun, 21 Sep 2025 16:17:57 GMT

Good to hear it works now!

Closing case,
Kenneth

RE: nrf54L15 : Unable to use UARTE00 P2.0, P2.2, P2.3, P2.4 not able to send data.

varsha@ — Sat, 20 Sep 2025 05:15:48 GMT

Thankyou so much.

I configured the pin P2.2 as UART00 TX on the Custom Board and it worked.

I appreciate the help you provided.

RE: nrf54L15 : Unable to use UARTE00 P2.0, P2.2, P2.3, P2.4 not able to send data.

Kenneth — Fri, 19 Sep 2025 21:36:25 GMT

[quote user="varsha@"]Is this applicable to only DK or is it in general for custom boards as well?. [/quote]

This is a limitation in the chip.

Kenneth

RE: nrf54L15 : Unable to use UARTE00 P2.0, P2.2, P2.3, P2.4 not able to send data.

varsha@ — Fri, 19 Sep 2025 12:34:00 GMT

Hello Kenneth,

Thankyou for your response.

[quote userid="2111" url="~/f/nordic-q-a/124259/nrf54l15-unable-to-use-uarte00-p2-0-p2-2-p2-3-p2-4-not-able-to-send-data/548861"]I can't seem to find that P2.03 support UARTE00 TX?[/quote]

Is this applicable to only DK or is it in general for custom boards as well?.

RE: nrf54L15 : Unable to use UARTE00 P2.0, P2.2, P2.3, P2.4 not able to send data.

Kenneth — Wed, 17 Sep 2025 13:24:34 GMT

[quote user="varsha@"]The issue is on the DK right?[/quote]

Yes.

Kenneth

RE: nrf54L15 : Unable to use UARTE00 P2.0, P2.2, P2.3, P2.4 not able to send data.

varsha@ — Wed, 17 Sep 2025 08:37:18 GMT

In that case, I should be able to use this pin (P2.2 for TX) without any constrain on the custom board. The issue is on the DK right?

RE: nrf54L15 : Unable to use UARTE00 P2.0, P2.2, P2.3, P2.4 not able to send data.

Kenneth — Wed, 17 Sep 2025 08:15:12 GMT

[quote user="varsha@"]Okay, now can you please guide me how am I supposed to use P2.2 as TX and P2.0 as RX in nrf54l15 DK first, so I can use it later on the custom board.[/quote]

Wait until end of September when the new version of Board controller app is ready that allow disabling the flash that is on the DK where the pins are by default connected, ref Table 3 here:
https://docs.nordicsemi.com/bundle/ug_nrf54l15_dk/page/UG/nRF54L15_DK/hw_desription/connector_if.html

Kenneth

RE: nrf54L15 : Unable to use UARTE00 P2.0, P2.2, P2.3, P2.4 not able to send data.

varsha@ — Tue, 16 Sep 2025 20:30:28 GMT

Hello,

Okay, now can you please guide me how am I supposed to use P2.2 as TX and P2.0 as RX in nrf54l15 DK first, so I can use it later on the custom board.

I feel like Im making a mistake somewhere.

&pinctrl
{
	/omit-if-no-ref/ uart00_default: uart00_default {
		group1 {
			psels = <NRF_PSEL(UART_TX, 2, 2)>;
		};
		group2 {
			psels = <NRF_PSEL(UART_RX, 2, 0)>;
			// bias-pull-up;
		};
	};

	/omit-if-no-ref/ uart00_sleep: uart00_sleep {
		group1 {
			psels = <NRF_PSEL(UART_TX, 2, 2)>,
				<NRF_PSEL(UART_RX, 2, 0)>;
			low-power-enable;
		};
	};
};

&uart00 {
	compatible = "nordic,nrf-uarte";
	status = "okay";
	current-speed = <115200>;
	pinctrl-0 = <&uart00_default>;
	pinctrl-1 = <&uart00_sleep>;
	pinctrl-names = "default", "sleep";
};


///////////////////////////////////////////////////////////////////////

#include "header.h"

#define UART_USB_NODE   DT_NODELABEL(uart00)
const struct device *uart_dev_usb= DEVICE_DT_GET(UART_USB_NODE);
char usb_buff[10] = {0};
const struct uart_config uart_cfg_usb = {
 .baudrate = 115200,
 .parity = UART_CFG_PARITY_NONE,
 .stop_bits = UART_CFG_STOP_BITS_1,
 .data_bits = UART_CFG_DATA_BITS_8,
 .flow_ctrl = UART_CFG_FLOW_CTRL_NONE
};

static void uart_usb_cb(const struct device *dev, struct uart_event *evt, void *user_data)
{
//LOG_INF("uart_cb enum = %d\n\r",evt->type);
 switch (evt->type) 
 { 
    case UART_TX_DONE:
        printk("UART_TX_DONE \r\n");
    // do something
    break;  
    case UART_TX_ABORTED:
    // do something
    break; 


    case UART_RX_RDY:
        printk("UART_RX_RDY \r\n");
        printk("55555555 %s\r\n",usb_buff);

        break;  
    case UART_RX_BUF_REQUEST:
    // do something
    break;  
    case UART_RX_BUF_RELEASED:
        
    // do something
    break; 
    case UART_RX_DISABLED:
        uart_rx_enable(dev, (uint8_t *)usb_buff, sizeof(usb_buff), 500 * 1000);
        break;  
    case UART_RX_STOPPED:
    // do something
    break; 
    default:
    break; 
 }
}

void USB_init(void)
{   
    int err = 0; 
    if (!device_is_ready(uart_dev_usb)) 
        printk("err : device_is_ready\r\n");
    else
        printk("no err : device_is_ready\r\n");

    err = uart_configure(uart_dev_usb, &uart_cfg_usb);  
    if (err == -ENOSYS) 
    {
        printk("err = %d : uart_configure\r\n", err);
        // return -ENOSYS;
    }
    else
    {
        printk("err = %d : uart_configure\r\n", err);
    }

    err = uart_callback_set(uart_dev_usb, uart_usb_cb, NULL);
    if (err) 
    {
        printk("err = %d : uart_callback_set\r\n", err);
        // return err;
    }
    else
    {
        printk("err = %d : uart_callback_set\r\n", err);
    }
    uart_rx_enable(uart_dev_usb, (uint8_t *)usb_buff, sizeof(usb_buff), 1000*1000); 
}

void USB_printk(char *data,int len)
{
    int err = uart_tx(uart_dev_usb, data, len, 100);
    printk("err = %d\r\n", err);
}


////////////////////////////////////////////////////////////////


#include "header.h"
#include <nrfx_power.h>
LOG_MODULE_REGISTER(main);

int main(void)
{
    int ret = 0;
    LOG_INF("Enter into the main\r\n"); 
    ret = nrfx_power_constlat_mode_request();
    printk("ret = %d\r\n",ret);
    while (1)
    {
        USB_printk("hello\r\n",sizeof("hello\r\n"));
        k_msleep(100);
    }
}

The same code works if the pins are P1.4 and P1.5 and using UART20

RE: nrf54L15 : Unable to use UARTE00 P2.0, P2.2, P2.3, P2.4 not able to send data.

Kenneth — Tue, 16 Sep 2025 14:28:55 GMT

[quote user="varsha@"]So I guess it be possible to use P2.2 as TX (Swapping with P2.3) for UARTE00?[/quote]

That should work yes.

Kenneth

RE: nrf54L15 : Unable to use UARTE00 P2.0, P2.2, P2.3, P2.4 not able to send data.

varsha@ — Tue, 16 Sep 2025 11:39:44 GMT

Hello,

Thankyou For Confirming.

We figured that out later. We need this UART for logging.and we want to use only TX. So I guess it be possible to use P2.2 as TX (Swapping with P2.3) for UARTE00?

RE: nrf54L15 : Unable to use UARTE00 P2.0, P2.2, P2.3, P2.4 not able to send data.

Kenneth — Tue, 16 Sep 2025 11:19:49 GMT

Hi,

I can't seem to find that P2.03 support UARTE00 TX?
https://docs.nordicsemi.com/bundle/ps_nrf54L15/page/chapters/pin.html

Kenneth

RE: nrf54L15 : Unable to use UARTE00 P2.0, P2.2, P2.3, P2.4 not able to send data.

varsha@ — Tue, 16 Sep 2025 05:44:09 GMT

Hello,

I wanted to use P2.02 as RXD and P2.03 as TXD in NRF54L15. I am using a custom board.

My configuration looks like this on the dts File :

    /omit-if-no-ref/ uart00_default: uart00_default {
        group1 {
            psels = <NRF_PSEL(UART_TX, 2, 3)>;
        };
        group2 {
            psels = <NRF_PSEL(UART_RX, 2, 2)>;
            // bias-pull-up;
        };
    };

    /omit-if-no-ref/ uart00_sleep: uart00_sleep {
        group1 {
            psels = <NRF_PSEL(UART_TX, 2, 3)>,
                <NRF_PSEL(UART_RX, 2, 2)>;
            low-power-enable;
        };
    };
/////////////////////////////////////////////////////////////////////////////////////////////////////////
&uart00 {
    compatible = "nordic,nrf-uarte";
    status = "okay";
    current-speed = <9600>;
    pinctrl-0 = <&uart00_default>;
    pinctrl-1 = <&uart00_sleep>;
    pinctrl-names = "default", "sleep";
};

///////////////////////////////////////////////////////////////////////////////////////////////////////////

#include "header.h"

#define UART_USB_NODE   DT_NODELABEL(uart00)
const struct device *uart_dev_usb= DEVICE_DT_GET(UART_USB_NODE);
char usb_buff[10] = {0};
const struct uart_config uart_cfg_usb = {
 .baudrate = 9600,
 .parity = UART_CFG_PARITY_NONE,
 .stop_bits = UART_CFG_STOP_BITS_1,
 .data_bits = UART_CFG_DATA_BITS_8,
 .flow_ctrl = UART_CFG_FLOW_CTRL_NONE
};

static void uart_usb_cb(const struct device *dev, struct uart_event *evt, void *user_data)
{
//LOG_INF("uart_cb enum = %d\n\r",evt->type);
 switch (evt->type)
 {
    case UART_TX_DONE:
        printk("UART_TX_DONE \r\n");
    // do something
    break;  
    case UART_TX_ABORTED:
    // do something
    break;


    case UART_RX_RDY:
        f.gnss_uart_rx_F = 1;
        printk("RX Data :  %s\r\n",usb_buff);

        break;  
    case UART_RX_BUF_REQUEST:
    // do something
    break;  
    case UART_RX_BUF_RELEASED:
       
    // do something
    break;
    case UART_RX_DISABLED:
        uart_rx_enable(dev, (uint8_t *)usb_buff, sizeof(usb_buff), 500 * 1000);
        break;  
    case UART_RX_STOPPED:
    // do something
    break;
    default:
    break;
 }
}

void USB_init(void)
{  
    int err = 0;
    if (!device_is_ready(uart_dev_usb))
        printk("err : device_is_ready\r\n");
    else
        printk("no err : device_is_ready\r\n");

    err = uart_configure(uart_dev_usb, &uart_cfg_usb);  
    if (err == -ENOSYS)
    {
        printk("err = %d : uart_configure\r\n", err);
        // return -ENOSYS;
    }
    else
    {
        printk("err = %d : uart_configure\r\n", err);
    }

    err = uart_callback_set(uart_dev_usb, uart_usb_cb, NULL);
    if (err)
    {
        printk("err = %d : uart_callback_set\r\n", err);
        // return err;
    }
    else
    {
        printk("err = %d : uart_callback_set\r\n", err);
    }
    uart_rx_enable(uart_dev_usb, (uint8_t *)usb_buff, sizeof(usb_buff), 1000*1000);
}

void USB_printk(char *data,int len)
{
    int err = uart_tx(uart_dev_usb, data, len, 100);
    printk("err = %d\r\n", err);
}

Also Before transmitting, I used the function :

nrfx_power_constlat_mode_request();

I am using a loopback format.

I am using P1.4, P1.5 and P1.10, and P1.11 also, but did not face any issue while using those.

Is there something i need to change? Am I going wrong somewhere?

RE: nrf54L15 : Unable to use UARTE00 P2.0, P2.2, P2.3, P2.4 not able to send data.

Kenneth — Mon, 15 Sep 2025 19:22:09 GMT

Yes, but I can see that the app doesn't support this as of yet, it's planned end of September.

Kenneth

RE: nrf54L15 : Unable to use UARTE00 P2.0, P2.2, P2.3, P2.4 not able to send data.

varsha@ — Mon, 15 Sep 2025 08:06:40 GMT

Hello,

Sorry for the Late Response.

I did not understand what I need to configure in the Board Configurator. Are we talking about the application in nrf connect for Desktop?

RE: nrf54L15 : Unable to use UARTE00 P2.0, P2.2, P2.3, P2.4 not able to send data.

Kenneth — Tue, 09 Sep 2025 13:30:15 GMT

Hi,

I can see I had the other case, did you also see my follow up reply about board configurator?

Kenneth