https://devzone.nordicsemi.com/f/nordic-q-a/64066/a-problem-from-experimental----dfu-cover-application-code-in-nrf52840-dongleHi There I did 2 experimental for recovering boot-loader of nrf52840 dongle by download dfu (nRF5_SDK_16.0.0_98a08e2\examples\dfu\open_boot-loader\pca10059_usb_debug\ses\open_bootloader_usb_mbr_pca10059_debug.emProject). The difference of the 2 experimentalen-USTelligent Community 13Thu, 23 Jul 2020 22:58:19 GMThttps://devzone.nordicsemi.com/thread/261474?ContentTypeID=1Thu, 23 Jul 2020 22:58:19 GMT137ad170-7792-4731-bb38-c0d22fbe4515:e815e79c-0d58-4942-956b-2e4c10cfa6caDi-sheng<p>Hi Hung Bui</p> <p>I got it.</p> <p>Thanks,</p> <p>B,Rs</p> <p></p> <p>Di-Sheng</p> <p></p> <p><span></span></p> <p><span></span></p> <p><span></span></p> <p><span></span></p> <p><span></span></p> <p><span></span></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/261405?ContentTypeID=1Thu, 23 Jul 2020 14:31:01 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f5cd71e2-5d14-45da-93ce-71bb81d0c53dHung Bui<p>Hi again Dison,&nbsp;</p> <p>As I may have already explained to you in earlier cases, the limitation of the bootloader on the dongle is that it doesn&#39;t support chip erasing and only support application/softdevice/bootloader update.&nbsp;<br />This mean any application data stored on the board will stay after DFU update. This applied for the data that supposed to store provisioning data. This could be the reason why the light switch example won&#39;t work when you DFU update it.&nbsp;&nbsp;</p> <p>To solve this, you need to erase the board using the SWD interface.&nbsp;</p> <p><br />I wouldn&#39;t suggest to use the nRF52840 dongle as the development platform. You should better develop on nRF52840 DK and after the firmware ready you can flash/DFU the firmware on the dongle and test in the field.&nbsp;</p><div style="clear:both;"></div>