Printk statement not printing properly

RE: Printk statement not printing properly

Kevin_0987654 — Fri, 04 Oct 2024 12:08:00 GMT

Instead of using the usb I used a usb to ttl converter and connected the tx rx pins and it works properly. I'm still not able to get data from connecting usb directly to dev board

RE: Printk statement not printing properly

Priyanka — Tue, 01 Oct 2024 13:25:54 GMT

Hi Kevin,

Could you put the SW9 to VDD? Also make sure that SW10 is in the OFF position.

You are trying the default hello_world sample in ncs\v2.6.1\zephyr\samples\hello_world right?

I tried to reproduce it but could not. Please try building with the changes to the DK as mentioned above and let me know how it goes.

-Priyanka

RE: Printk statement not printing properly

Kevin_0987654 — Mon, 30 Sep 2024 08:38:46 GMT

As i mentioned earlier im using v2.6.1 (both toolchain and sdk). I tried the default Helloworld sample but didnt see any output till i put the print statement inside a loop. im attaching a picture of my DK

RE: Printk statement not printing properly

Priyanka — Thu, 26 Sep 2024 13:52:10 GMT

Hi Kevin,

Let's take a look step by step. Please tell me which SDK version are you working with? Is it 2.7.0?

Which DK revision are you using? You can find the details on the white sticker on the board.

Did you build the default hello world sample in the SDK without making any changes to it? If not, please try this.

What is you nRF Command Line Tools version?

-Priyanka

RE: Printk statement not printing properly

Kevin_0987654 — Thu, 26 Sep 2024 10:11:15 GMT

Im pretty sure Im missing something here. Im just using the USB cable connected to the DK to see this, I'm not using any pins. I am connecting to the com port and just viewing the data in NRF connect serial terminal. The hello world example was not printing anything i thought it might be too fast and so i put it in a while loop and got output:

Hello `rlHello hrlHello `rl Hello `rld Hello `rld

code:

* SPDX-License-Identifier: Apache-2.0

#include <stdio.h>

#include <zephyr/kernel.h>

int main(void)

{

while (true) {

// Your code here, e.g., printing or processing

printf("Hello World! %s\n", CONFIG_BOARD);

// Sleep for 1 second (1000 milliseconds)

k_sleep(K_MSEC(1000));

}

return 0;

}

P.S: Unknown symbol CONFIG_UART_CONSOLE_BAUDRATE

RE: Printk statement not printing properly

Priyanka — Thu, 26 Sep 2024 09:08:19 GMT

Hi Kevin,

Which pins are you using for UART tx and rx? Please verify that you use the correct pin numbers. Could you try adding the following to prj.conf:

CONFIG_LOG_DEFAULT_LEVEL=4
CONFIG_LOG_MODE_DEFERRED=n

You could also try to explicitly set the baud rate by

CONFIG_UART_CONSOLE_BAUDRATE=115200

If you still have the issue, please try to run a simple hello world sample and we can check if you get a proper output.

-Priyanka

RE: Printk statement not printing properly

Kevin_0987654 — Thu, 26 Sep 2024 06:02:17 GMT

I have tried it. I dont know if it is beacuse of that but output seems slightly more readable

LED stte:LED stte:LED stte:LED stte:LED stte:LED stte:HLED stte:LED stWLED stte:HLED stte:@

But it is still not proper.

proj.conf

CONFIG_GPIO=y

CONFIG_LOG_PRINTK=y

CONFIG_CONSOLE=y

CONFIG_UART_CONSOLE=y

if i also enable CONFIG_LOG=y I get output

LED s@te: `
LED s@te@PLED s`te:@p
LED s@te:HP
LED s`te:@ p@LED s@te:@

here is the code:

* SPDX-License-Identifier: Apache-2.0

#include <zephyr/kernel.h>

#include <zephyr/drivers/gpio.h>

#include <zephyr/sys/printk.h>

/* 1000 msec = 1 sec */

#define SLEEP_TIME_MS 1000

/* The devicetree node identifier for the "led0" alias. */

#define LED0_NODE DT_ALIAS(led0)

* A build error on this line means your board is unsupported.

* See the sample documentation for information on how to fix this.

static const struct gpio_dt_spec led = GPIO_DT_SPEC_GET(LED0_NODE, gpios);

int main(void)

{

int ret;

if (!gpio_is_ready_dt(&led)) {

return 0;

}

ret = gpio_pin_configure_dt(&led, GPIO_OUTPUT_ACTIVE);

if (ret < 0) {

return 0;

}

bool led_state = true;

while (1) {

ret = gpio_pin_toggle_dt(&led);

if (ret < 0) {

return 0;

}

led_state = !led_state;

printk("LED state: %s\r\n", led_state ? "ON" : "OFF");

k_msleep(SLEEP_TIME_MS);

}

return 0;

}

I am also using the default device tree file nrf52840dk_nrf52840.dts that comes with the sdk without any overlays. I am using NRF serial terminal to see the output with 115200 8n1 Flowcontrol:off. Is there any msg length limitation that is causing messages to overlap?

RE: Printk statement not printing properly

Priyanka — Wed, 25 Sep 2024 13:08:50 GMT

HI Kevin,

Could you try using CONFIG_LOG_PRINTK=y

Regards,

Priyanka