https://devzone.nordicsemi.com/f/nordic-q-a/115936/programming-custom-board-with-nrf52840Hello, I have developed a custom board for the nrf52840 with the QFAA QFN48 package. I am trying to program it with my nRF52840, I am using P20 of the DKconnecting the following way: 2 &amp; 3 VDD of my device which is powered by 3 V 4en-USTelligent Community 13Wed, 30 Oct 2024 13:28:06 GMThttps://devzone.nordicsemi.com/thread/508526?ContentTypeID=1Wed, 30 Oct 2024 13:28:06 GMT137ad170-7792-4731-bb38-c0d22fbe4515:531db709-4264-42c8-80e1-1bc3f748ede1ketiljo<p>The connection to the DK seems to be correct. The schematic looks ok as well so you might have solder issues.&nbsp;</p> <p>The layout isn&#39;t good though, so even if you get this working, the performance will be bad. Take a look at the reference layout. Most components are placed where they are of a reason:&nbsp;<a href="https://nsscprodmedia.blob.core.windows.net/prod/software-and-other-downloads/reference-layouts/nrf52840/nrf52840-qfaa-reference-layout-1_0.zip">https://nsscprodmedia.blob.core.windows.net/prod/software-and-other-downloads/reference-layouts/nrf52840/nrf52840-qfaa-reference-layout-1_0.zip</a></p> <p><img style="max-height:240px;max-width:320px;" src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/pastedimage1730294580740v1.png" alt=" " /></p> <p>The RF section is critical:</p> <p><img style="max-height:240px;max-width:320px;" src="https://devzone.nordicsemi.com/cfs-file/__key/communityserver-discussions-components-files/4/pastedimage1730294607565v3.png" alt=" " /></p> <p>And the placement of the decopling caps; they need to be close to the pins in the schematic.&nbsp;</p> <p>The antenna need tuning components, see this whitepaper, chapter 4.2:&nbsp;<a href="https://docs.nordicsemi.com/bundle/nwp_017/resource/nwp_017.pdf">https://docs.nordicsemi.com/bundle/nwp_017/resource/nwp_017.pdf</a></p> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p> <p></p><div style="clear:both;"></div>