Using UART1 for the serial communication

[Stjepan Brlecic]

I am using nRF5340DK and would like to send and receive data to computer via UART1 and pins "TX", "RX", "CTS" and "RTS" using USB TO RS232 SERIAL CONVERTER.

This way I would keep UART0 for logging.

But I can't receive or send data via UART1.

I'm using the Segger IDE and the Peripheral_UART for the first nRF5340 DK board and the Central_UART example for the second board.

Im trying to use UART1 in Peripheral_UART example.

For now I changed settings for UART1 in zephyr.dst file

uart1: uart@9000 {
  compatible = "nordic,nrf-uarte";
  reg = < 0x9000 0x1000 >;
  interrupts = < 0x9 0x1 >;
  status = "okay";
  label = "UART_1";
  current-speed = < 0x4b00 >;
  tx-pin = < 0x21 >;
  rx-pin = < 0x20 >;
  rts-pin = < 0x0b >;
  cts-pin = < 0x0a >;
};

And i added in autoconfig.h

#define CONFIG_NRFX_UARTE1 1
#define CONFIG_UART_NRFX 1
#define CONFIG_UART_1_NRF_UARTE 1
#define CONFIG_UART_1_ENHANCED_POLL_OUT 1
#define CONFIG_UART_1_ASYNC 1
#define CONFIG_UART_1_NRF_TX_BUFFER_SIZE 32

It won't work with UART1.

When I switch back to UART0 it works fine.

What could be a problem?

[Stjepan Brlecic]

Now my overlay file looks like this

&uart1 {
  compatible = "nordic,nrf-uarte";
  reg = < 0x9000 0x1000 >;
  interrupts = < 0x9 0x1 >; 
  status = "okay";
  label = "UART_1";
  current-speed = < 0x4b00 >;
  tx-pin = < 0x21 >;
  rx-pin = < 0x20 >;
};
&i2c1 {
  status = "disabled";
};

But again it doesn't work.

It seems to me that the changes to the overlay file make no difference, how can I check?

These are the files that I'm changing.

[Øivind]

You can't use those tx and rx pins without changing a few things in the board files, which will impact the network core.
That's why I recommended using pin 34 and 35 instead.

You can check whether the overlay is being applied in build/zephyr/zephyr.dts

[Stjepan Brlecic]

As i suspected the .dts file is not changing, do you perhaps know what the reason would be?

I change the overlay file and then in Segger IDE run these 2 commands.

Is that enough? 

[Øivind]

Oh, no that is not enough. When using SES, you need to run "Project->Run CMake" after changes to overlay files, prj.conf etc.

[Stjepan Brlecic]

Now when I use run "Project-> Run CMake" .dts file is changed and looks fine.

uart1: arduino_serial: uart@9000 {
  compatible = "nordic,nrf-uarte";
  reg = < 0x9000 0x1000 >;
  interrupts = < 0x9 0x1 >;
  status = "okay";
  label = "UART_1";
  current-speed = < 0x4b00 >;
  tx-pin = < 0x22 >;
  rx-pin = < 0x23 >;
};

Now I use pins 34 --> P1.02 and 35 --> P1.03 as you recommended.

Wires -> ORANGE -> TXD; YELLOW -> RXD;

An error that occurred before is gone,

but a new error occurs...

OUTPUT

Not able to allocate UART receive buffer2

CODE

static void uart_work_handler(struct k_work *item)
{
      struct uart_data_t *buf;

      buf = k_malloc(sizeof(*buf));
      if (buf) {
            buf->len = 0;
      } else {
            printk("Not able to allocate UART receive buffer2\n");
            k_work_reschedule(&uart_work, UART_WAIT_FOR_BUF_DELAY);
            return;
      }

      uart_rx_enable(uart, buf->data, sizeof(buf->data), UART_WAIT_FOR_RX);
}

I believe the problem is here buf = k_malloc(sizeof(*buf));

, do you have any idea why this is happening?

Do I miss any other settings?