https://devzone.nordicsemi.com/f/nordic-q-a/93450/gpio-configurationHi Team, We would like to connect external LEDs to the NRF52840DK controller. We could not find any unused GPIO pins to connect. We have referred manual but it showing all 48 GPIO pins are already connected. Kindly help us to find unused GPIOen-USTelligent Community 13Tue, 01 Nov 2022 17:15:49 GMThttps://devzone.nordicsemi.com/thread/393534?ContentTypeID=1Tue, 01 Nov 2022 17:15:49 GMT137ad170-7792-4731-bb38-c0d22fbe4515:bdb325e2-cda2-4357-9bfc-3a6e63962739Karl Ylvisaker<p>Hello,<br /><br />The <a href="https://infocenter.nordicsemi.com/topic/ug_nrf52840_dk/UG/dk/connector_if.html">description of the used pins can be seen in the Connector Interface section of the nRF52840 DK documentation</a>.<br />You will also need to check the recommended usage for the pin in <a href="https://infocenter.nordicsemi.com/topic/ps_nrf52840/pin.html">the nRF52840 SoC Pin Assignment documentation</a> before you select which of the pins you would like to use for your application.</p> [quote user=""]Can I use existing in-built LED GPIO pins for existing in-built SPI GPIO pins?[/quote] <p>Please elaborate on what you would like to use the LEDs for here.<br />If you would like the onboard LEDs to blink when a SPI transfer is happening you can connect their pin toggling TASK to the SPI event that you are interested in (such as TX start) through the PPI peripheral, and then they will toggle/set/clear whenever that SPI event is generated. Using PPI will also make the EVENT trigger the TASK directly, without requiring CPU interaction to do so, which both makes the action faster and use less power consuming.<br /><br />Best regards,<br />Karl</p><div style="clear:both;"></div>