RE: How to debug nRF52 without RTT?

Dusan Daniska — Mon, 12 Mar 2018 07:23:51 GMT

I have played around with this yesterday and got it working. Hope this answer helps someone new to nRF programming...

The steps that I performed are:

install Putty Tray (I got some problems with old and good Putty when connecting to serial port)
check the NRF_LOG_BACKEND_UART_BAUDRATE in sdk_config.h
connect putty (yes, I mean Putty Tray) to serial port, use the baudrate from above and also check other UART connection params (parity, stop bit, control flow)

put this code into main.c:

#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"

...

int main(void) {
  APP_ERROR_CHECK(NRF_LOG_INIT(NULL));
  NRF_LOG_DEFAULT_BACKENDS_INIT();

  ...
  
  NRF_LOG_INFO("Hello, UART debugging.")
  
  ...
}

if using Makefile to compile/link the project, add following lines to Makefile (read the comments):

# add these .c files to SRC_FILES

   $(SDK_ROOT)/components/libraries/experimental_log/src/nrf_log_backend_rtt.c \
   $(SDK_ROOT)/components/libraries/experimental_log/src/nrf_log_backend_serial.c \
   $(SDK_ROOT)/components/libraries/experimental_log/src/nrf_log_backend_uart.c \
   $(SDK_ROOT)/components/libraries/experimental_log/src/nrf_log_default_backends.c \
   $(SDK_ROOT)/components/libraries/experimental_log/src/nrf_log_frontend.c \
   $(SDK_ROOT)/components/libraries/experimental_log/src/nrf_log_str_formatter.c \

# add these folders to INC_FOLDERS

  $(SDK_ROOT)/components/libraries/experimental_log \
  $(SDK_ROOT)/components/libraries/experimental_log/src \

compile/link/flash

Now you should see the logs in the putty terminal.

RE: How to debug nRF52 without RTT?

Dusan Daniska — Mon, 12 Mar 2018 07:14:40 GMT

I agree, but I've read some posts that RTT consumes much memory. Maybe it has been fixed already but I still believe that something as simple as UART is less hungry than some extensive 3rd party library. And I believe that debugging over UART is enough for many projects. Therefore I am trying to setup the UART debugging.

RE: How to debug nRF52 without RTT?

Turbo J — Sun, 11 Mar 2018 21:37:43 GMT

The NRF52 DK has the required j-link for RTT build-in. Its the same one uses to program the chip, and the RTT viewer should be installed together with the other SEGGER tools.