UART example does not work.

[twar]

Hello.

What do I need to run this example called uart?

As far as I understand this should be simple echo program meaning what comes in goes out but I can not see anything on terminal. I tried to enable NRF_LOG_ENABLED with CMSIS but after that I got bunch of linkage errors:

1> "C:/tools/SEGGER/SEGGER Embedded Studio for ARM 3.50/gcc/arm-none-eabi/bin/ld" -X --omagic -eReset_Handler --defsym=__vfprintf=__vfprintf_long --defsym=__vfscanf=__vfscanf_int -EL --gc-sections "-TC:/nordic/nRF5_SDK_15.0.0_a53641a/examples/peripheral/uart/pca10040/blank/ses/Output/uart_pca10040 Release/Obj/uart_pca10040.ld" -Map Output/Release/Exe/uart_pca10040.map -u_vectors -o Output/Release/Exe/uart_pca10040.elf --emit-relocs "@C:/nordic/nRF5_SDK_15.0.0_a53641a/examples/peripheral/uart/pca10040/blank/ses/Output/uart_pca10040 Release/Obj/uart_pca10040.ind"
1> Output/uart_pca10040 Release/Obj/app_error_weak.o: In function `app_error_fault_handler':
1> C:\nordic\nRF5_SDK_15.0.0_a53641a\components\libraries\util/app_error_weak.c:58: undefined reference to `nrf_log_panic'
1> C:\nordic\nRF5_SDK_15.0.0_a53641a\components\libraries\util/app_error_weak.c:58: undefined reference to `nrf_log_frontend_dequeue'
1> C:\nordic\nRF5_SDK_15.0.0_a53641a\components\libraries\util/app_error_weak.c:61: undefined reference to `nrf_log_frontend_std_0'
1> C:\nordic\nRF5_SDK_15.0.0_a53641a\components\libraries\util/app_error_weak.c:103: undefined reference to `nrf_log_frontend_std_0'
1> Output/uart_pca10040 Release/Obj/app_error_weak.o: In function `__NOP':
1> C:\nordic\nRF5_SDK_15.0.0_a53641a\examples\peripheral\uart\pca10040\blank\ses/../../../../../../components/toolchain/cmsis/include/cmsis_gcc.h:375: undefined reference to `m_nrf_log_app_logs_data_dynamic'
Build failed

When I tried to add source file containing those definition (nrf_log_frontend.c) to the project I got another missing references. Is there any simple solution to fix this?

btw I've built this project with SES.

Best regards.

[AndreasF]

Hi.

NRF_LOG_ENABLED is a macro used for the logger module, not the UART module, which this example uses.

If you disable NRF_LOG_ENABLED and build the example it should compile and work as intended.

- Andreas

[twar]

OK, I've disabled that login module and it compiled but it does not seems to work.

I compiled it and flash and reset the board. Then run https://ttssh2.osdn.jp/ set connection to j-link and baud to 115200.
Then type some random characters (except q or Q) in tera term window but there is no echo but it should be. Am I right?

[AndreasF]

Hi.

It should work, I suspect you might have wrong configurations in TeraTerm.

These are the configurations I used in Termite 3.4:

As you can see, it gave me a echo output:

- Andreas

[twar]

Above are my settings and I can type as long as I want but there's no any output.

Yet another observation from my side, when I start debugging it works it echo every character I type until q or Q but in "normal  mode" (without debugging) I can not see anything.

[AndreasF]

Hi.

Have you check for "Local echo", "Receive: AUTO", and "Transmit: LF" under Setup --> Terminal..., like this:

When you type either "q" or "Q" the program terminates into a while-loop, as shown at the bottom of the main-loop in the code:

        uint8_t cr;
        while (app_uart_get(&cr) != NRF_SUCCESS);
        while (app_uart_put(cr) != NRF_SUCCESS);

        if (cr == 'q' || cr == 'Q')
        {
            printf(" \r\nExit!\r\n");

            while (true)
            {
                // Do nothing.
            }
        }

Here you can see I typed "q":

- Andreas

[twar]

Yeah, just checked those options and nothing has changed, I even change program logic to this:

while (true)
{
uint8_t cr='t';
while (app_uart_put(cr) != NRF_SUCCESS);
nrf_delay_ms(100);
}

so it sends lower case letter t every 100ms but I can not see anything on my terminal unless I start debugging.

when I flash the board in "normal" way nothing shows up on terminal.

Yet another edit:

It turned out that there is something wrong with terminal configuration on my pc, on other computer it works fine.

Thank you for help and best regards.

[AndreasF]

Hi.

It should work as intended with these configurations. I suggest you start from scratch with an unmodified version of this example.

Download and unzip the nRF5_SDK_15.0.0_a53641a\examples\peripheral\uart example, compile it without doing any modfications and without any debugging, and use the configurations I suggested for Tera Term, and see if this works.

If this doesn't work, could you please attach this project in a .zip file so I can have a look at it?

- Andreas