How to update Timestamp using the time.h library in NRF52840

[Techist]

Hello guys,

I'm stuck trying to produce a timestamp for data synchronization in my project. I have gone through some of the issues raised in this regard but none was actually helpful. 

Currently I am using the time.h library, but the time doesn't get updated. it keeps printing the same time.

Now I tried using a static incrementing counter to update the ".tm_secs" struct member, Now the time updates over as the counter increment. but the minute and hour field soesn't get updated when ".tm_secs" gets to 59.

I don't know if this is the best approach, but I just want to produce a time epoch, I can always set the epoch with the current time over my GSM modem.

[ovrebekk]

Hi 

I recently did something similar in a hobby project of mine, where I needed to keep track of time. 

I set the time using the clock_settime(..) function, like this:

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struct tm start_time;
struct timespec ts;
time_t t;

start_time.tm_year = 122;
start_time.tm_mon = 0;
start_time.tm_mday = 24;
start_time.tm_hour = 8;
start_time.tm_min = 12;
start_time.tm_sec = 12;
t = mktime(&start_time);

ts.tv_sec = t;
ts.tv_nsec = 0;

clock_settime(CLOCK_REALTIME, &ts);

 

Then I can simply read out the time like this:

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// Check current time 
t = time(NULL);
ptr = localtime(&t);

You can find the source here.

Best regards
Torbjørn 

[Techist]

While I have solved the underlying issue, I will try this out and compare what I have with yours. Thank you, sir!

Edit: I have tried replicating this code but I ran into this error:

main.c:67: undefined reference to `clock_settime'
collect2.exe: error: ld returned 1 exit status
ninja: build stopped: subcommand failed.
FATAL ERROR: command exited with status 1: 'C:\ncs\toolchains\31f4403e35\opt\bin\cmake.EXE' --build 'c:\nordic\myapps\firmware\app\build' 

I have included these libraries:

#include <time.h>

/* clock_gettime() prototype */

#include <zephyr/posix/time.h>

but the error keeps occurring.

[Techist]

I have fixed the error, i included "

CONFIG_POSIX_CLOCK=y

"

in my prj.conf file.

Thanks!!!!

[ovrebekk]

Glad I could help. The best of luck with your project