https://devzone.nordicsemi.com/f/nordic-q-a/85984/nrf21540-question---csn-signal-when-not-using-spiI don&#39;t have enough pins to dedicate a SPI bus to the nRF21540. In the webinar I attended I believe I heard that the SPI bus is not supported by the current SDK anyway, or at least that you don&#39;t need the SPI bus. Regarding the /CSN signal when noten-USTelligent Community 13Mon, 21 Mar 2022 09:02:38 GMThttps://devzone.nordicsemi.com/thread/359040?ContentTypeID=1Mon, 21 Mar 2022 09:02:38 GMT137ad170-7792-4731-bb38-c0d22fbe4515:33f132d4-cc5c-431b-9cad-f11e616de0bfPaKa<p>You are not checking the latest version of the nRF21540 PS, section 5.1 has been updated and the statement removed. Tie CSN to VDD.</p><div style="clear:both;"></div>