UART P0.01 pin stays low

Question

Hi all,

I am trying to set up UART communication on the nrf9160. I am using the nrf9160 DK and zephyr.

I have selected device UART_1 and after I cal functions device get_binding() and uart_configure() I can send data over the the virtual port VCOM2.

However TX pin P0.01 stays LOW all the time. Does anybody know anything about this issue?

nrf9160_pca.dts_compliled snippet

uart1: uart@9000 {
				compatible = "nordic,nrf-uarte";
				reg = < 0x9000 0x1000 >;
				interrupts = < 0x09 0x01 >;
				status = "okay";
				label = "UART_1";
				current-speed = < 0x1c200 >;
				tx-pin = < 0x01 >;
				rx-pin = < 0x00 >;
				rts-pin = < 0x0e >;
				cts-pin = < 0x0f >;
			};

proj.config snippet:

CONFIG_SERIAL=y
CONFIG_TRUSTED_EXECUTION_NONSECURE=y
CONFIG_UART_INTERRUPT_DRIVEN=y
CONFIG_UART_0_NRF_UARTE=y
CONFIG_UART_1_NRF_UARTE=y

struct device *uart_dev;

void uart_init(void){
  int err=0;
  struct uart_config uart_settings;
  uart_dev = device_get_binding(UART_NAME);
  if(uart_dev == NULL){
    printk("error:could not get %s binding\n",UART_NAME);
    return;
  }
  uart_settings.baudrate = 115200;
  uart_settings.parity = UART_CFG_PARITY_NONE;
  uart_settings.stop_bits = UART_CFG_STOP_BITS_1;
  uart_settings.data_bits = UART_CFG_DATA_BITS_8;
  uart_settings.flow_ctrl = UART_CFG_FLOW_CTRL_NONE;
  err = uart_configure(uart_dev,&uart_settings);
  if(err == 0){
    printk("configured uart\n");
    printk("Value of NRF_UARTE1_NS->PSEL.RXD: %lu \n",  (unsigned long)NRF_UARTE1_NS->PSEL.RXD);
    printk("Value of NRF_UARTE1_NS->PSEL.TXD: %lu \n",  (unsigned long)NRF_UARTE1_NS->PSEL.TXD);
  }
  else{
    printk("error could not configure uart\n");
  }

}

int main(void) {
  printk("Starting application\n");

  uart_init();
  
  u8_t string[] ="AWAKE\r\n";
  u8_t* test_ptr = string;

  while (true) {

   for(int i=0; i<sizeof(string);i++){
    uart_poll_out(uart_dev,*test_ptr);
    //printk("%c",*test_ptr);
    test_ptr++;
   }
   test_ptr = string;
   k_sleep(100);
  }

  return 0;
}