NRF SDK 15.3 UART example is not working. - nRF52840 pca10056

[Casper Kronborg Pedersen]

Hi DevZone,

I am developing an application that needs to use UART communication with the nRF52840 pca10056 board.

I am using Segger Embedded Studio V4.16

I checked out the UART example found in the SDK files under \examples\peripheral\uart\pca10056\blank\ses\

I have setup my terminal program PuTTY with 115200 Baudrate, 8 Data bits, 1 Stop bit, No Parity and No Flow Control.

The example compiles fine, but  does not run. I get no echo in the terminal as expected.

When i build and debug, I immediately end up in the app_error_weak.c file at line 100 - NRF_BREAKPOINT_COND;

Are there any know issues with this example? I have searched the DevZone and did not find any related posts.

I hope you can point me in the right direction.

Br. Casper

[BinderT]

Hi,

Have you added this macro in. It's commented out by default.

line 66 in the example
#define ENABLE_LOOPBACK_TEST

Regards

[Casper Kronborg Pedersen]

Yes I also tried enabling loopback test, but the same error occurs.

[Casper Kronborg Pedersen]

Hi,

Yes I compiled it straight out of the box. Just tried copying your code in and the error persists I am afraid.

Br. Casper

EDIT:
From what I can see when debugging, then the m_event_handler(&app_uart_event); is called in app_uart_fifo.c

This then goes directly into the app_error_fault_handler(NRF_FAULT_ID_SDK_ERROR, 0, (uint32_t)(&error_info)); in line 73 in app_error.c

The error code is 0x00000004

[AndreasF]

Hi.

Have you modified any source files used by different drivers in the SDK?

Could you try to compile the example from a clean SDK?

Best regards,

Andreas

[Casper Kronborg Pedersen]

Hi,

After the first fault I was worried about the same thing, so I unzipped a fresh copy of the SDK. But that did not solve the problem either.

Br. Casper

[Casper Kronborg Pedersen]

I have learned that error code 0x0000004 is representing NRF_ERROR_NO_MEM.

When I build my project the memory allocation looks as follows:

Is this the same for you?

Br. Casper

[Casper Kronborg Pedersen]

I have located the problem.

The UART on the development kit uses pins P0.05, P0.06, P0.07, P0.08.

I was using one if these pins (P0.08) for another device connected to the development kit.

I don't know why I got a NRF_ERROR_NO_MEM error code from this mistake, but at least now the example works as expected with echoing keyboard inputs on the terminal.

Thank you for helping me. It is much appreciated! :)

Br. Casper

[awneil]

Casper Kronborg Pedersen said:

I don't know why I got a NRF_ERROR_NO_MEM error code from this mistake

Possibly because you were getting framing errors on the UART:

https://devzone.nordicsemi.com/f/nordic-q-a/41480/multiperipheral-nus-crashes/161677#161677

[Casper Kronborg Pedersen]

Interesting read. This will probably save me in the near future. I did spend some time looking into the wrong things because of the NRF_ERROR_NO_MEM message.

Thank you for posting!

Br. Casper