https://devzone.nordicsemi.com/f/nordic-q-a/5258/question-about-gpio-input-controlHello, I have a problem with GPIO Input control My sensor work on special clock generated by MCU I&#39;ve controlled this sensor by Arduino like this //SCK digital pin 4, SDIO digital pin 5 digitalWrite(SCKI,HIGH); // bit22 delayMicrosecondsen-USTelligent Community 13Tue, 27 Jan 2015 15:38:12 GMThttps://devzone.nordicsemi.com/thread/18398?ContentTypeID=1Tue, 27 Jan 2015 15:38:12 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a8375f04-f4cc-4c07-8732-676bfa2295a0Stefan Birnir Sverrisson<p>Hi</p> <p>If you still have problems, perhaps <a href="https://github.com/NordicSemiconductor/nrf51-powerdown-examples/blob/master/system-on-wakeup-on-gpio/main.c">this code</a> could help you out.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/18399?ContentTypeID=1Fri, 23 Jan 2015 08:33:46 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a832c8c0-8d89-477a-bfb3-2c9503bb3517Nguyen Hoan Hoang<p>before you could call those nrf_gpio_pin_xx you need to configure them first as input or output using nrf_gpio_cfg_output or nrf_gpio_cfg_input.</p><div style="clear:both;"></div>