no output on RTT viewer using zephyr

[villa_dev]

Hello,

I am beginner with Zephyr and for sure i have problems. I am trying to make simple app in order to get "hello World" via RTT viewer without success. I have read a lot of cases with similar problems and i have tested all solutions but no way.

I am using PCB MDK dongle with nrf52840 assembled (https://wiki.makerdiary.com/nrf52840-mdk-usb-dongle/). I have access to pins SWD (RST, SWDCLK and SWDIO, but SWO is not HW mapped). I could flash the PCB without problems using external J-Link and RTT viewer is conneted correctly but once APP is running there is no output in the terminal.

RTT viewer version 7.80C

Zephyr version 3.2.99

prj.conf is

# nothing here

CONFIG_PRINTK=y

CONFIG_CONSOLE=y
CONFIG_UART_CONSOLE=n
CONFIG_RTT_CONSOLE=y
# Enable RTT
CONFIG_USE_SEGGER_RTT=y

CONFIG_LOG=y
CONFIG_LOG_BACKEND_RTT=y
CONFIG_LOG_BACKEND_UART=n
CONFIG_LOG_PRINTK=y

source:

#include <zephyr/kernel.h>
#include <zephyr/sys/printk.h>
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(main);

void main(void)
{
	while (1){
		printk("Test printk\n");
		k_sleep(K_SECONDS(1));
		LOG_INF("Info message example.");
		k_sleep(K_SECONDS(1));
	}
}

Could any body help me, please?

Thanks in advance!

[Menon]

Hello,

Your prj.conf and main.c file looks good. Is this because of any wrong configuration you tried inside the RTT viewer (see the screenshot below)? Is there any another active JLink connection while you are trying?

Please expect some delay from our side as we very thinly staffed due Easter Vacation here in Norway.

Kind Regards,

Abhijith

[villa_dev]

Hello,

Definitely you gave me the solution!I had simultaneously connected J-Link Commander to power on the device and J-Link RTT Viewer. Once i have closed commander everything runs as expected. Thanks so much and have a nive easter vacaction!