How to add timestamp in RTT viewer using NRF log module

[frodyteen]

Currently developing on NRF52 sdk12 with a terminal

In my source code i have nrf_log_init(null), and this allows me to print stuff to the RTT viewer.

Now I want to be able to show time stamp minutes:seconds:miliseconds on my RTT viewer, when I print my data out from the uC. I'm looking at the on the Nordic infocenter nRF Log Module , and it seems like that I have to initiate the time stamp function by passing a parameter in the init function below:

ret_code_t nrf_log_init	(	nrf_log_timestamp_func_t 	timestamp_func	)	

Currently, in my source code, I have this parameter set be NULL. So, what do I replace the NULL with in order to print out time stamp?

if someone could write out an example on how to use the timestamp function in NRF log module, then it would be great.

Thank you all for your time.

[kobyfr]

This will achieve adding time-stamps to NRF logs, in some of the nRF example applications.

1. Add this to main .c

uint32_t get_rtc_counter(void)
{
    return NRF_RTC1->COUNTER;
}

2. Change this in main.c

uint32_t err_code = NRF_LOG_INIT();

to this

uint32_t err_code = NRF_LOG_INIT(get_rtc_counter);

3. Change sdk_config.h

from this

#define NRF_LOG_USES_TIMESTAMP 0

to this

#define NRF_LOG_USES_TIMESTAMP 1

The result will be to change logs from this:

<info> app: Setting vector table to bootloader: 0x000F1000
<info> app: Setting vector table to main app: 0x00026000
<info> app: Buttonless DFU Application started.
<info> app: RTC 8211
<info> app: Received indication state 1
<info> app: Received indication state 0

to this:

[00:00:00.000,000] <info> app: Setting vector table to bootloader: 0x000F1000
[00:00:00.000,000] <info> app: Setting vector table to main app: 0x00026000
[00:00:00.440,002] <info> app: Buttonless DFU Application started.
[00:00:00.440,032] <info> app: RTC 14419
[00:00:22.580,566] <info> app: Received indication state 1
[00:00:30.905,548] <info> app: Received indication state 0

[Srinivas V]

Hi Team,

What is the resolution of this time stamp, like [00:00:30.905,548] , like  [ Hr:Min:Sec:Msec ].

Regards,

Srinivas.V

[N Ashelman]

Note:

You will probably also need to change another line in sdk_config.h (line 3 in this excerpt):

// <o> NRF_LOG_TIMESTAMP_DEFAULT_FREQUENCY - Default frequency of the timestamp (in Hz) or 0 to use app_timer frequency. 
#ifndef NRF_LOG_TIMESTAMP_DEFAULT_FREQUENCY
#define NRF_LOG_TIMESTAMP_DEFAULT_FREQUENCY 0
#endif

The number 0 should be changed to the correct frequency.

For example, my code was using LFCLK with PRESCALER = 1. 

Per here, the counter increment frequency is 32768 / (PRESCALER + 1 ), so I set the number to 0x8000 / (1+1) = 0x4000

[Varun]

can we trust this timestamp for debugging? curious to know...
thank you

[FK42]

Adding this in case anyone else runs in the same issue I had when implementing this:

I had the issue that the timestamps wouldn't increment/ increase after a while. 

To fix it, I enabled everything related to the RTC1 counter in sdk_config.h. After which I set the RTC_default_config_frequency to a lower value.

I guess it has to do with the counter reaching the maximum value.