https://devzone.nordicsemi.com/f/nordic-q-a/24821/trouble-with-buttonless-dfu-when-using-nrf52832-and-nrf-toolboxHi, My SDK version is 13.0 and my problem is when I run the examples\ble_peripheral\experimental_ble_app_buttonless_dfu project the 52DK seems ok but when I use the DFU in nRF Toolbox App, I have connected the 52DK and about uploading files, the erroren-USTelligent Community 13Fri, 01 Sep 2017 13:08:23 GMThttps://devzone.nordicsemi.com/thread/97723?ContentTypeID=1Fri, 01 Sep 2017 13:08:23 GMT137ad170-7792-4731-bb38-c0d22fbe4515:76cd098d-8cdc-4177-b98e-d141f6807256Hung Bui<p>Hi Gz, You need to test the bootloader first before you test the buttonless example. I suggest you to have a look at <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v13.0.0/examples_bootloader.html?cp=4_0_2_4_2">the documentation of the bootloader</a>. You can follow my guide <a href="https://devzone.nordicsemi.com/blogs/1085/getting-started-with-nordics-secure-dfu-bootloader/">here</a>. Buttonless guide is at the end.</p><div style="clear:both;"></div>