https://devzone.nordicsemi.com/f/nordic-q-a/39177/swdio-pin-pcb-layoutHello, I made a PCB of the nRF51822 chip and tried to program it with a simple led toggle code, but am not able to see any output, I am trying to figure out what is wrong with my PCB and why it isn&#39;t programming. I stumbled upon the nRF51 DK schematicen-USTelligent Community 13Thu, 04 Oct 2018 11:19:34 GMThttps://devzone.nordicsemi.com/thread/151638?ContentTypeID=1Thu, 04 Oct 2018 11:19:34 GMT137ad170-7792-4731-bb38-c0d22fbe4515:94e793ad-e8cf-411a-be38-b4b567808229Kenneth<p>Hi,</p> <p>There is an internal pull up on the SWDIO already, so that is not a problem.</p> <p>You should only need to connect GND, VDD, SWDIO and SWDCLK to program the board.&nbsp;(And GND_DETECT if you are using a nRF51-DK as programmer). Make sure that VDD voltage is supported by the programmer (e.g. 3 - 3.3V if you are using a nRF51-DK as programmer).</p> <p>Best regards,<br />Kenneth</p><div style="clear:both;"></div>