No Logs on Custom board based on nrf52840 SoC

[Bhumika]

Hi,

I had my application based on nRF_SDK_For_Thread_and_Zigbee, and now I am porting my application to nRF_Connect_SDK.

When I use the nRF52840 DK board for testing purposes of any feature, I get logs on the JLink RTT viewer, but when I connect my custom board, I don't get any logs on the JLink RTT viewer.

I have made a board for my custom board in zephyr's board directory. I have used the nrf52840dk_nrf52840 board directory and replicated it for my custom board. I have mainly changed pins for LEDs, Buttons, and I2C communication on my custom board. Also, I have built the application for my custom board using the command " west build -b custom_board_name" and to flash
the custom board, I am using DK board as a programmer and a JTag connector, connecting SWDIO, SWDCLK, Vdd,  and Gnd from DK board to custom board. However, when I flash my code to dk_board, which is compiled for my custom_board, it shows RTT logs on JLinkRTTViewer.

Earlier also on my "nRF_SDK_For_Thread_and_Zigbee" based application I used to follow the same procedure and was able to view RTT logs for my custom board.

Can you suggest what is wrong here?

[Jørgen Holmefjord]

Hi,

Which nRF Connect SDK version are you using, and which sample are you building?

Have you followed the instructions in How to use RTT to enabled RTT logging in the sample?

Have you verified that the custom board is being flashed correctly and can run other applications?

Did you connect the external board through P19 debug out connector, or P20 pin header? Is VTG connected to VDD for the DK to detect the external board?

Best regards,
Jørgen

[Jørgen Holmefjord]

Do your custom board have the 32 kHz crystal and additional components required for the DCDC regulator?

[Bhumika]

yes.

In fact on that board, I get logs when the application based on nRF_SDK_thread is run.

[Jørgen Holmefjord]

Can you try out one of the BLE peripheral samples, for instance Bluetooth: Peripheral UART, which should have RTT enabled by default. Then check with nRF Connect on a mobile phone to verify that the device is Advertising, and check if you get any output on your RTT viewer?

Also, which version of J-Link are you using?

[Bhumika]

My application is getting hung somewhere on my custom board, but I am unable to get it where.

However, it is running seamlessly on DK board

[Jørgen Holmefjord]

Does it hang immediately after powering on the board, or does it happen only after a time?

The usual reason for this is that the custom board does not have the 32.768kHz low frequency crystal mounted, so the application is waiting for the crystal to start. If you do not have the crystal, you can configure the application to use the internal RC oscillator.

[Bhumika]

Thanks for your support.

My application has crystal to start with.

This seems to be some issue with my logging module due to which my node is facing a HARD FAULT and MPU FAULT. 

I made the code simplified and simply tried some logs on my custom node which is working.

So the issue is not with the custom board but in my application somewhere else.

I will try to debug that issue and create another ticket if needed for specifically that issue.