printk() function is not showing output in the Segger terminal emulator window

[oldViking]

Hi,

I have loaded one of the basic samples( nrf connect SDK, fade_led  ) into my nrf52DK.

Using the free run mode or the debugger almost everything seems to work correctly.  However, I do not see any output for the printk() statements.

Using the debugger, if I set a break point after this statement:     printk("PWM-based LED fade\n");       The output text is still not present.

Attempting to connect with the terminal emulator causes an error message 'cannot open serial link "COM1" '.

What am I missing here ?

Thank you

oldViking

[Amanda Hsieh]

Hi, 

What debugger are you using? Segger or VScode?

You can check with the Device Manager for the com port number of the JLinkCDC UART Port.

Regards,
Amanda

[oldViking]

Hi Amanda,      I am using Segger.  Per your instructions I checked the device manager to see which com port it has assigned to the JLinkCDC.  It was using COM3, changed my emulator properties so it is using COM3.  Now I can  connect the terminal emulator without an error message.

However, still not getting output string when the printk() function is executed on the emulator.

Baud Rate 9600, No flow control, 8 data bits, 1 stop bit. All these settings look OK.

oldViking

[Amanda Hsieh]

Hi, 

oldViking said:

I am using Segger.

See How to use RTT for the setting to get SEGGER’s J-Link RTT log. Here is the example hello_world_RTT.7z

To see the UART output, see How to connect with PuTTY. You can test with the zephyr\samples\hello_world

-Amanda 

[oldViking]

Hi Amanda,

I copied the prj.conf file from hello_world_RTT, and placed it into my fade_led.

Now I can see the printk() statements in my debug console.

Thankyou

oldViking

[Amanda Hsieh]

Happy to know it can work.

-Amanda