nRF5340 UART Interrupt mode send example

[SergeySK]

Hi all!
I'm currently working on the UART on the nRF5340 board. The SDK describes three options:
-polling API,
-interrupt-driven API,
-asynchronous API.
With Polling and Asynchronous - everything is clear and they do not suit me for various reasons.
Interrupt-driven doesn't have any APIs for starting (sending the first byte).
Searched everything.
Please share a link to an example.

[Sigurd Hellesvik]

Hi,

So that we are on the same page: Can you send me the link to the documentation you refer to?

The SDK describes three options:

Regards,
Sigurd Hellesvik

[SergeySK]

Hello Sigurd!

I have already searched through mountains in search of information. Start here
UART — Zephyr Project Documentation (nordicsemi.com)

I used the "peripheral_uart" example from SDK 2.0.0 to start with, but it uses an asynchronous uart.
I couldn't find an example with an interrupt driven API.

[Sigurd Hellesvik]

Hi Sergii,

Sorry for the late answer!

But I hopefully have information that can help you: the Zephyr UART echo sample uses interrupt driven UART for receiving messages, so you could learn how to do this from that sample.

Is this what you were looking for?

Regards,
Sigurd Hellesvik

[SergeySK]

Hey Sigurd!
In general, no problem - I myself like to work at night :)
Unfortunately, there is example given by you, the conclusion is made using blocking calls

/*
	* Print a null-terminated string character by character to the UART interface
	*/
	void print_uart(char *buf)
	{
	int msg_len = strlen(buf);
	for (int i = 0; i < msg_len; i++) {
	uart_poll_out(uart_dev, buf[i]);
	}
	}

I need the same thing, but with the interrupt.

[ovrebekk]

Hi Sergii

Sigurd is currently unavailable, and I will help you with this case in the mean time. 

Any particular reason why the async driver would not be suitable? If you are handling a lot of communication this should be more efficient. 

The hci_uart sample in Zephyr uses the interrupt driver both in TX and RX, and you can have a look at that to see how you can handle the TX part in the interrupt. In particular have a look at this section in main.c.

Best regards
Torbjørn