nRF52840 SDK16 - Print an array of hex values using NRF_LOG_HEXDUMP_INFO

[Nikosant03]

Hi everyone,

I want to serial print an array of bytes in hex format. The array size is 200bytes. I tried to use the NRF_LOG_HEXDUMP_INFO but it doesn't print all the array, it prints just the first 72bytes

The second approach works fine. How I would like to use the  NRF_LOG_HEXDUMP_INFO since it is an out of the box function.

// First approach
  NRF_LOG_HEXDUMP_INFO(read_raw_data,read_payload);

// Second approach
  char changeline = 20;
  for (int i = 0; i < read_payload; i++) {
    NRF_LOG_RAW_INFO("0x%x ", read_raw_data[i]);
    NRF_LOG_FLUSH();
    if (i == changeline-1) {
      NRF_LOG_RAW_INFO("\r\n");
      changeline += 20;
    }
  }

Thanks in advance

Nick

[Vidar Berg]

Hi Nick,

Please try to increase the NRF_LOG_MSGPOOL_ELEMENT_COUNT setting in sdk_config.h as Torbjørn suggested in this post: https://devzone.nordicsemi.com/f/nordic-q-a/66041/nrf_log_hexdump_-raises-data-access-violation-fault-if-a-large-buffer-is-used. 

[Nikosant03]

Hi Vidar and thank you for your support,

This merely solve the problem.. By increasing the NRF_LOG_MSGPOOL_ELEMENT_COUNT  I can print "all" the buffer but some of the data are not get printed as shown below

This is how I call the function

#define read_payload 100
char read_raw_data[read_payload] = {0};

NRF_LOG_HEXDUMP_INFO(read_raw_data,read_payload);
NRF_LOG_FLUSH();

[Vidar Berg]

So you are not losing logs if you use Putty, or did you meant to say that you are still losing logs?

[Nikosant03]

No I don't losing data thanks. I will proceed with UART.

However I was wondering whyI lose data with RTT... but if this is complicated to investigate nevermind :)

[Vidar Berg]

Ok, that's good to know, thanks for confirming. But were you using Putty with RTT or UART?  I guess it has something to do with the Jlink RTT settings. I will try to look into it. Maybe it would help to increase the RTT buffers.

[Vidar Berg]

Increasing the size of the RTT buffers seem to do the trick:

[Nikosant03]

xmm interesting, I miss something because it's still don't work for me. I don't know if this is related, but I read the data from a .hex file and then I fill the read_raw_data buffer. Lastly I print the logs using the  NRF_LOG_HEXDUMP_INFO.

This is the complete function

FRESULT ff_result;
#define read_payload 100
  static char read_raw_data[read_payload] = {0};
  UINT br = 0;

  // NA - Open the file to write
  ff_result = f_open(&file, "RAWDATA.hex", FA_READ);
  if (ff_result != FR_OK) {
    NRF_LOG_INFO("Unable to open file: %u", ff_result);
    NRF_LOG_FLUSH();
    return;
  }

  ff_result = f_read(&file, read_raw_data, read_payload, &br);
  if (ff_result != FR_OK) {
    NRF_LOG_INFO("\r\nUnable to read the file: %u", ff_result);
    NRF_LOG_FLUSH();
    return;
  }

  // NA - Close the file
  ff_result = f_close(&file); // NA - The f_close function closes an open file. Ref: http://elm-chan.org/fsw/ff/doc/close.html
  if (ff_result != FR_OK) {
    NRF_LOG_ERROR("\r\nUnable to close file: %u", ff_result);
    NRF_LOG_FLUSH();
    return;
  }
  NRF_LOG_INFO("Close the file");

  // Print the data
  NRF_LOG_HEXDUMP_INFO(read_raw_data,read_payload);
  NRF_LOG_FLUSH();

}

#define NRF_LOG_BACKEND_RTT_ENABLED 1

#define NRF_LOG_BACKEND_RTT_TEMP_BUFFER_SIZE 64

#define NRF_LOG_BACKEND_UART_ENABLED 0

#define SEGGER_RTT_CONFIG_BUFFER_SIZE_UP 660

#define SEGGER_RTT_CONFIG_MAX_NUM_UP_BUFFERS 14

#define NRF_LOG_MSGPOOL_ELEMENT_SIZE 20

#define NRF_LOG_MSGPOOL_ELEMENT_COUNT 40

With the current settings I receive the following

I also tried your example, however with the same results.. So I suppose that the it's not something wrond with my function.

[Vidar Berg]

Hi,

Please try to repeat the test with nRF5 SDK 17.0.2, if you have time. I tried to repeat the test now with SKD 16.0.0, but the message got capped at 167 bytes for some reason. I don't remember if I used SDK 16 or 17 when it worked ( I thought it was with SDK 16 but not sure anymore)

[Nikosant03]

Ok, I'll try thanks!!