https://devzone.nordicsemi.com/f/nordic-q-a/53822/nrf52840-buttonless-dfu-errorDear All. I&#39;m using nRF52840 DK, 15.3.0 SoftDevice, Segger. I&#39;m testing DFU and have some question. and i&#39;m begginer with all I&#39;m so s orry in advance. First. I flashed example &quot; ble_app_buttonless_dfu&quot; but it crashed with &quot;no bootloaderen-USTelligent Community 13Wed, 13 Nov 2019 00:09:59 GMThttps://devzone.nordicsemi.com/thread/219776?ContentTypeID=1Wed, 13 Nov 2019 00:09:59 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a513132b-b9d3-4e37-bdc6-5fec53cf56b0swna3708<p>sorry for late reply</p> <p>I successfully made it <span class="emoticon" data-url="https://devzone.nordicsemi.com/cfs-file/__key/system/emoji/1f642.svg" title="Slight smile">&#x1f642;</span></p> <p>thank you</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/217547?ContentTypeID=1Wed, 30 Oct 2019 13:29:27 GMT137ad170-7792-4731-bb38-c0d22fbe4515:739dd6bc-38da-46a4-a97e-302d3c03bf2cHung Bui<p>Hi Swna,&nbsp;</p> <p>I would suggest you to test using the bootloader first, before you testing with the buttonless application.&nbsp;<br />The buttonless application is just offering a way to enter the bootloader without holding button 4.&nbsp;</p> <p>Please follow the guide <a href="https://devzone.nordicsemi.com/nordic/nordic-blog/b/blog/posts/getting-started-with-nordics-secure-dfu-bootloader#_cptype=root">here </a>to test the bootloader.&nbsp;</p> <p>After that you can follow the documentation <a href="https://infocenter.nordicsemi.com/topic/sdk_nrf5_v16.0.0/ble_sdk_app_buttonless_dfu.html?cp=5_1_4_2_2_6">here </a>to test the buttonless.&nbsp;</p><div style="clear:both;"></div>