no device detected, or readback protection may be sethttps://devzone.nordicsemi.com/f/nordic-q-a/40782/no-device-detected-or-readback-protection-may-be-setHi, I am facing the problem as shown in the image below for two PCA10040 and two PCA10028 boards. I read related posts but none of them helped!! I did not make any changes on the development kits in terms of hardware. I&#39;m using the latest versions ofen-USTelligent Community 13Thu, 22 Nov 2018 08:22:40 GMTRE: no device detected, or readback protection may be sethttps://devzone.nordicsemi.com/thread/158553?ContentTypeID=1Thu, 22 Nov 2018 08:22:40 GMT137ad170-7792-4731-bb38-c0d22fbe4515:93d2b44a-ccca-42c7-9585-3f76563ef772haakonsh<p>p0.21 is the reset pin. For some reason it has a weak pull to GND. Normally it is the opposite, a pull to VDD.&nbsp;</p><div style="clear:both;"></div>RE: no device detected, or readback protection may be sethttps://devzone.nordicsemi.com/thread/158514?ContentTypeID=1Wed, 21 Nov 2018 22:33:32 GMT137ad170-7792-4731-bb38-c0d22fbe4515:5e8e9c63-fc9d-42d2-bc1c-8a3556a52301bscdb<p>Okay so this got solved by connecting P0.21 to VDD. But why this has to be done? When I remove the connection it does not work.</p><div style="clear:both;"></div>