https://devzone.nordicsemi.com/f/nordic-q-a/9084/nrf51822-connot-be-detected-by-segger-on-nrf51-dkI have tried to flash my application targeting nRF51822 on our board by using a Segger on nRF51 DK. However, Keil compiler always shows that it couldn&#39;t find any nRF51822 target (and always flashes the nRF51422 on the nRF51DK). I am not sure that Ien-USTelligent Community 13Wed, 09 Sep 2015 07:02:14 GMThttps://devzone.nordicsemi.com/thread/33428?ContentTypeID=1Wed, 09 Sep 2015 07:02:14 GMT137ad170-7792-4731-bb38-c0d22fbe4515:34002d74-2693-4ea5-a3e7-1e1f815c6639teddy.c<p>Thank you very much. Now, nRF2GO can sucessfully detect the nRF51822.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/33427?ContentTypeID=1Mon, 07 Sep 2015 10:40:55 GMT137ad170-7792-4731-bb38-c0d22fbe4515:675cbd25-20bf-495d-891f-8695efdac148MartinBL<p>Hi</p> <p>It looks like you have forgotten to connect VTG (pin 3 on the header in your picture (P20)). The VTG pin should be connected to Vdd on your board. This is essential as VTG is measuring the voltage on your external board. If it does not measure any voltage the nRF51DK will assume that there is no external board connected.</p><div style="clear:both;"></div>