https://devzone.nordicsemi.com/f/nordic-q-a/20886/nrf51822-dev-kit-works-but-the-pcb-doesn-t-how-can-i-fix-itI am working on a project for college in which I need to build my own PCB. The code works fine on the Dev Kit but on the PCB, the bluetooth is not showing. I have tried looking up as to why but I can not see the problem. The final device is meant to been-USTelligent Community 13Wed, 29 Mar 2017 06:50:50 GMThttps://devzone.nordicsemi.com/thread/81563?ContentTypeID=1Wed, 29 Mar 2017 06:50:50 GMT137ad170-7792-4731-bb38-c0d22fbe4515:98f307ee-5eed-41d6-9a0e-e9a5b143dc74FormerMember<p>When making a design with the nRF51 is it very important to copy the reference layout (and schematic). The reference layout can be found <a href="http://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.nrf51%2Fdita%2Fnrf51%2Fpdflinks%2Fref_layout.html&amp;cp=3_6">here</a>. For making a design that works well, I would recommend you to read and follow the tutorial &quot;<a href="https://devzone.nordicsemi.com/tutorials/25/">General PCB design guidelines for nRF51</a>&quot;.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/81562?ContentTypeID=1Tue, 28 Mar 2017 18:40:07 GMT137ad170-7792-4731-bb38-c0d22fbe4515:60a8e860-5448-4e7e-a6a6-b7f7cf649f49Daniel Wang<p>You don&#39;t have a 16 MHz crystal on XC1/XC2? For nRF51 an external 16 MHz crystal is mandatory in order to use BLE...</p><div style="clear:both;"></div>