? on using Arduino shield that needs external power with nRF51 DKhttps://devzone.nordicsemi.com/f/nordic-q-a/7628/on-using-arduino-shield-that-needs-external-power-with-nrf51-dkScenario: I want to use an Arduino shield with the nRF51 DK. When attached to an Arduino, the Arduino&#39;s barrel jack is plugged into a 12V power supply. The shield takes advantage of the Arduino&#39;s voltage regulator so that both the 12V needed for a pumpen-USTelligent Community 13Thu, 18 Jun 2015 16:49:18 GMTRE: ? on using Arduino shield that needs external power with nRF51 DKhttps://devzone.nordicsemi.com/thread/27215?ContentTypeID=1Thu, 18 Jun 2015 16:49:18 GMT137ad170-7792-4731-bb38-c0d22fbe4515:dd119ac7-410a-45f2-a41c-86a24e568851i_am_trying<p>Thank you. Your answer is a good explanation. I upvoted.</p><div style="clear:both;"></div>RE: ? on using Arduino shield that needs external power with nRF51 DKhttps://devzone.nordicsemi.com/thread/27214?ContentTypeID=1Thu, 18 Jun 2015 16:47:14 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d87cc6db-106c-4e15-9f52-3d3dc8970e21Stian R&#248;ed Hafskjold<p>No there is no voltage regulator in the &quot;external supply&quot; header. So if you apply 12V on that pin the board will be broken.</p> <p>The Vin pin on Arduino corresponds to the bottom pin on the p1 header on the nRF51 DK, which is not connected.</p> <p>So, the nrf51 DK does not handle 12V and do not supply 12V on the Vin pin to the Arduino. I guess you setup would be: USB to the nRF DK to supply 5V to the shield, and then connect 12V to the Vin on the shield.</p> <p>You can find the schematics for the nRF DK here: <a href="http://www.nordicsemi.com/eng/nordic/Products/nRF51-DK/nRF51-DK-HW/38675">www.nordicsemi.com/.../38675</a></p><div style="clear:both;"></div>