NCS v2.0.0 - aws_iot sample - No UART output when using an overlay file

[alvin.le]

Hi,

I'm working with the NCS v2.0.0 - aws_iot sample and an nRF9160 on a custom board.

I have tested the aws_iot sample on an nRF9160DK and have confirmed that it works.

It appears that when I attempt to use an overlay file to change the TX and RX pins of UART_0, the UART output stops working.

I have tested this overlay file using hello world sample on my custom board and it outputs as expected.

I have attached my overlay file below, could you let me know what might be happening?

Thanks,

Alvin

6431.nrf9160dk_nrf9160_ns.overlay

[Simon]

If you look at GPIO interfaces and Virtual COM port you can see that P0.00 and P0.01 are connected to the Interface MCU. So when changing to these pins, the output should go out to another COM port when using P0.00 and P0.01.

I tested this myself. First I connected the nRF9160 DK to the computer, and then I ran nrfjprog --com, and got the following output:

$ nrfjprog --com
960013235 COM37 VCOM1
960013235 COM38 VCOM2
960013235 COM39 VCOM0

I then tried to program the hello_world sample to the nRF9160 DK, and the UART log was output on COM39. Then I applied your overlay file, and UART log was now output on COM38. See the below image.

Do you see the same behaviour on your side? If not, could you upload your project here?

Best regards,

Simon

[alvin.le]

Hi Simon,

I can confirm that using the overlay file with the hello_world sample works on my custom board. I was getting UART communication on P0.00 and P0.01.

However when I attempt to use the same overlay file on the aws_iot sample, it no longer outputs anything on the UART.

The aws_iot sample I'm using was found in the NCS v2.0.0 toolchain nrf > samples > nrf9160 > aws_iot

Thanks,

Alvin

[jchan12345]

Did you see the bootup message *** Booting Zephyr OS build v3.1.99-ncs1 *** and nothing else after that ??

[alvin.le]

When I add in the overlay file and use SPM (CONFIG_SPM=y and CONFIG_BUILD_WITH_TFM=n) in the prj.conf file, I do not see *** Booting Zephyr OS build v3.1.99-ncs1 ***. The last thing I see is:

SPM: prepare to jump to Non-Secure image.

[jchan12345]

I may be facing a different problem.  I am using the peripheral_lbs example with NCS V2.1.0 .  It works on nRF5340DK, but if I change the overlay file.  Only "*** Booting Zephyr OS build v3.1.99-ncs1 *** message received on my custom board which indicates the MCUBoot works with my overlay file, but stepping thru printk() in the peripheral_lbs main.c not seeing more messages printed.  The application is running fine with the debugger.   I am debugging, but it may be different from your problem.