https://devzone.nordicsemi.com/f/nordic-q-a/42349/could-someone-explain-me-where-is-my-mistakesHi folks, I try to do create timer. Therefore i want to adding some files in blinky project. So here is some screen shot. Thats about debug error. First i used SDK 15.2 than i tried to added nrfx_drv_timer.c files. I didn&#39;t find SDK files. Than Ien-USTelligent Community 13Thu, 10 Jan 2019 10:02:37 GMThttps://devzone.nordicsemi.com/thread/164861?ContentTypeID=1Thu, 10 Jan 2019 10:02:37 GMT137ad170-7792-4731-bb38-c0d22fbe4515:3c667efd-1e82-4485-a0b9-e675a0672a26lemon<p>Maybe you can realize the app_timer module . It&#39;s easier to use , and the hrs demo has the usage of app_timer module&nbsp;&nbsp;</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/164838?ContentTypeID=1Thu, 10 Jan 2019 08:51:05 GMT137ad170-7792-4731-bb38-c0d22fbe4515:75cb4831-b493-4dba-b253-57d99c1e70c8rraa<p>Thanks for your answer lemon.</p> <p>But actually i want to add different timer in blinky project. I checked peripheral examples. If i be succeed i would control some gpio.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/164835?ContentTypeID=1Thu, 10 Jan 2019 08:45:53 GMT137ad170-7792-4731-bb38-c0d22fbe4515:65767583-3f11-4d7c-8868-9737a69baab1lemon<p>If you only want to add a timer ,just&nbsp; reference the&nbsp; Demo of nRF5_SDK_15.2.0_9412b96\examples\peripheral\timer, remember don&#39;t use timer0 which is used by softdevice.</p><div style="clear:both;"></div>