https://devzone.nordicsemi.com/f/nordic-q-a/11547/flashing-to-nrf52I have the following: Dev board PCA10040 SDK nRF52_SDK_0.9.2_dbc28c9 Mac OSx I was able to compile the blinky example and have the .hex in the _build folder. Pardon me but this is the first time that i am working with a nordic platformen-USTelligent Community 13Tue, 26 Jan 2016 15:55:31 GMThttps://devzone.nordicsemi.com/thread/43649?ContentTypeID=1Tue, 26 Jan 2016 15:55:31 GMT137ad170-7792-4731-bb38-c0d22fbe4515:62d6d462-022f-4411-ac32-2f77da1c1b85kennethlimcp<p>It says JLINK when i plug to my mac and LD5 blinks when i power it using a USB power adaptor.</p> <p>I will try out the blog method and see how it goes :)</p> <p><strong>EDIT:</strong> Great! The Jlink method worked!</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/43648?ContentTypeID=1Tue, 26 Jan 2016 15:36:24 GMT137ad170-7792-4731-bb38-c0d22fbe4515:3641ddd3-4d6c-410b-9a3d-10ba7efc5374Ole Bauck<p>The drag and drop function seems a little unstable with PCA10040 hex files, it seems it only works after a full erase have been done with nrfjprog or nRFgo studio. I suggest you use nrfjprog (a part of nRF command line tools) or nRFgo studio for flashing. You can find them <a href="https://www.nordicsemi.com/eng/Products/Bluetooth-Smart-Bluetooth-low-energy/nRF52-DK">here</a>.</p> <p>If LD5 is blinking it may indicate that the programming chip is in bootloader state. Do the disk say &quot;BOOTLOADER&quot;? In that case turn on and off the DK. If you dragged the hex file over while the programming chip was in bootloader state you may want to upload the <a href="https://www.nordicsemi.com/eng/nordic/download_resource/52275/4/16015644">original bootloader</a> again. See the <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52.v1.0.0/development/dev_kit/int_mcu_firmw.html?cp=1_0_2_0_2">DK user guide</a> for more.</p> <p><strong>EDIT:</strong> I noticed that you are using Mac OSx. See <a href="https://devzone.nordicsemi.com/blogs/22/getting-started-with-nrf51-development-on-mac-os-x/">this blog</a> or <a href="https://devzone.nordicsemi.com/blogs/498/tools-for-os-x-development/">this blog</a> for which tools to use.</p><div style="clear:both;"></div>