UART unable to confiogure

[Nordic_Swapnil]

Please refer screen shot attach
I am able to configure uart0 but not able to configure uart1,2,3

i am receiving multiple errors while same code is working fine for uart0.

I am using zephyre OS , 

i am using latest nrf Connect SDK 2.7.0

H/W nrf52840dk/nrf52840.

refer sample code

#include <zephyr/kernel.h>

#include <zephyr/device.h>

#include <zephyr/devicetree.h>

#include <zephyr/drivers/gpio.h>

#include <zephyr/drivers/uart.h>

#include <zephyr/sys/printk.h>

#define SLEEP_TIME_MS 1000

const struct device *uart = DEVICE_DT_GET(DT_NODELABEL(uart1));

static uint8_t tx_buf[] =   {"SLS TEST Validation ==nRF Connect SDK Fundamentals Course\r\n"

                             "1 TO 100 kit\r\n"};

//static void uart_cb(const struct device *dev, struct uart_event *evt, void *user_data);

int main(void) {

    int ret;

if(!device_is_ready(uart)){

    printk("UART Device not Ready\r\n");

    return 1 ;

    }

 while (1) {

       

ret = uart_tx(uart, tx_buf, sizeof(tx_buf), SYS_FOREVER_US);

    if(ret){

        return 1;

    }

k_msleep(SLEEP_TIME_MS);

    }

    return 0;

}

[Håkon Alseth]

Hi,

 

nRF52840 has two UARTE instances:

https://docs.nordicsemi.com/bundle/ps_nrf52840/page/uarte.html#d1676e397

 

The newer Cortex M33 based devices, such as nRF5340 and nRF91-series, they have up to 4 UART instances, which are shared with SPI and TWI.

 

If you want to use uart1, you have to enable it in device tree:

&uart1 {
    status = "okay";
};

 

Kind regards,

Håkon

[Nordic_Swapnil]

heyy Hakon,
I tried this step it had only eliminated the error and program is compiled successfully
But I am still not getting output string, i had configured settings same as uart0 for uart1.

[Håkon Alseth]

Hi,

 

Nordic_Swapnil said:

But I am still not getting output string, i had configured settings same as uart0 for uart1.

You cannot enable both uart1 and uart0 on the same pins. one will need to be enabled on other pins, and you have to connect a external uart adapter to be able to communicate.

 

Kind regards,

Håkon

[Nordic_Swapnil]

YES !  i did the same thanks for support,
I observed that it is working for P0.06,P0.08 and P1.01,P1.02

latest 2.7 version sdk dont suggest pins, cant just random choose pins to configure

[Håkon Alseth]

Hi,

 

Glad to hear that you got it working!

If you want to change the pins, you can ask the AI, in the lower right corner.

For instance "show me how to change pins on uart1", and it'll give you a device tree overlay showing something like this:

&pinctrl {
   uart1_default_alt: uart1_default_alt {
      group1 {
         psels = <NRF_PSEL(UART_TX, 0, 14)>,
                 <NRF_PSEL(UART_RX, 0, 16)>;
      };
   };
   /* required if CONFIG_PM_DEVICE=y */
   uart1_sleep_alt: uart1_sleep_alt {
      group1 {
         psels = <NRF_PSEL(UART_TX, 0, 14)>,
                 <NRF_PSEL(UART_RX, 0, 16)>;
         low-power-enable;
      };
   };
};

&uart1 {
  pinctrl-0 = <&uart1_default_alt>;
  /* if sleep state is not used, use /delete-property/ pinctrl-1; and
   * skip the "sleep" entry.
   */
  pinctrl-1 = <&uart1_sleep_alt>;
  pinctrl-names = "default", "sleep";
};

Change this to the GPIO that you wanted.

 

Kind regards,

Håkon