https://devzone.nordicsemi.com/f/nordic-q-a/16385/delve-in-header-files-understanding-sdkI&#39;m sorry for general question, but I need it for my calming down. I&#39;m delving step by step go throught header files into origin definition of function for understanding the core of simple example (blinky in my case). I&#39;m stuck in function There&#39;reen-USTelligent Community 13Wed, 14 Sep 2016 12:13:34 GMThttps://devzone.nordicsemi.com/thread/62725?ContentTypeID=1Wed, 14 Sep 2016 12:13:34 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a7bfd167-41db-44cd-b1ca-e20ca86891cdStas<p>I didn&#39;t notice it, my fault. Thanks a lot for helping.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/62724?ContentTypeID=1Wed, 14 Sep 2016 10:52:02 GMT137ad170-7792-4731-bb38-c0d22fbe4515:333b8454-81ad-456a-8a60-e73396014aa9Hung Bui<p>Hi Stas,</p> <p>nrf_gpio_cfg() is defined in nrf_gpio.h . It utilize the NRF_GPIO-&gt;PIN_CNF[] register. You use PIN_CNF[] register when you want atomic operation to change the configuration of a pin. You can find what you need to feed in this function by looking at the description of the PIN_CNF register in the nRF51 or nRF52 Reference Manual.</p> <p>You can directly access the registers if you like, our library just provide an abstract layer on top of the register, make it easier to use.</p><div style="clear:both;"></div>