https://devzone.nordicsemi.com/f/nordic-q-a/111503/nrf52840-dk-set-uart-rx-to-p0-09Hi, I am using https://github.com/NordicDeveloperAcademy/nRF-Connect-SDK-Fundamentals lesson5/fund_less5_exer1. I am able to receive UART message using default UART RX P0.08 pin. But, when I change the UART RX to P0.09 using this overlay code it doesen-USTelligent Community 13Fri, 24 May 2024 13:09:43 GMThttps://devzone.nordicsemi.com/thread/485830?ContentTypeID=1Fri, 24 May 2024 13:09:43 GMT137ad170-7792-4731-bb38-c0d22fbe4515:08fdc93f-8118-49e8-a2ff-bb3f7b4aa520mtrobregado<p>Hi,</p> <p>I changed it to UART RX P0.26, UART TX P0.27 and it worked.</p> <p>Regards,</p> <p>Markel</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/485824?ContentTypeID=1Fri, 24 May 2024 12:49:37 GMT137ad170-7792-4731-bb38-c0d22fbe4515:70951904-61e1-4ad8-9d24-48d21b2a2928H&#229;kon Alseth<p>Hi,</p> <p>&nbsp;</p> <p>P0.09 / P0.10 are NFC pins, and require some adjustment if you want to use them as GPIOs on the nRF52840-DK:</p> <p><a href="https://infocenter.nordicsemi.com/topic/ug_nrf52840_dk/UG/dk/hw_nfc_if.html?cp=5_0_4_7_10">https://infocenter.nordicsemi.com/topic/ug_nrf52840_dk/UG/dk/hw_nfc_if.html?cp=5_0_4_7_10</a></p> <p>&nbsp;</p> <p>In addition, you need to specify in UICR that the nfct pins are to be used as gpios:</p> <p><pre class="ui-code" data-mode="text">&amp;uicr { nfct-pins-as-gpios; }; </pre></p> <p>&nbsp;</p> <p>An alternative option is to choose any other available GPIOs you have in your design.</p> <p>&nbsp;</p> <p>Kind regards,</p> <p>Håkon</p><div style="clear:both;"></div>