https://devzone.nordicsemi.com/f/nordic-q-a/20690/sdk13-buttonless-dfu-can-t-start-bootloaderhi,dear engineers, i use the example experimental_ble_app_buttonless_dfu of nRF5_SDK_13.0.0_04a0bfd, on the PCA10040 board,Now,i&#39;m sure that I am flashed Softdevice,app,and bootloader,and the board work in the app.and well,the nRF connect v1.1 isen-USTelligent Community 13Wed, 22 Mar 2017 05:13:32 GMThttps://devzone.nordicsemi.com/thread/80701?ContentTypeID=1Wed, 22 Mar 2017 05:13:32 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6ee3f7f1-1348-43e0-8754-c3b9b7710248Liang Shuan<p>see the guide there</p> <p>From SDK v13 we introduced DFU buttonless characteristic. The characteristic has indication and write properties. What we need to do is simply enable indication on the characteristic and write 0x01 to it. The Buttonless device will send an indication and wait for acknowledge from the DFU master. When the acknowledge from the central comes, it will call bootloader_start() (check on_hvc() function in ble_dfu.c). The connection will be dropped after that.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/80700?ContentTypeID=1Wed, 22 Mar 2017 05:01:35 GMT137ad170-7792-4731-bb38-c0d22fbe4515:684e810f-dd9c-4036-a158-26826e78d8ceAdrian Eggenberger<p>What was the reason for the nrfconnect to fail?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/80702?ContentTypeID=1Wed, 22 Mar 2017 02:34:57 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a48b02af-122f-4d5d-b97e-afb486562908Liang Shuan<p>i am found the reason. just follow this <a href="https://devzone.nordicsemi.com/blogs/1085/getting-started-with-nordics-secure-dfu-bootloader/">devzone.nordicsemi.com/.../</a></p><div style="clear:both;"></div>