https://devzone.nordicsemi.com/f/nordic-q-a/55206/nrf5240-dfu-update-over-bleHai , I need to update nrf52840 over ble from esp32 . first i tried with app , firmware gets updated .. as per the dfu protocol i understood flow and tried to writing data to the characteristic step by step from esp32.i can able to send and get responsesen-USTelligent Community 13Thu, 05 Dec 2019 12:50:23 GMThttps://devzone.nordicsemi.com/thread/223903?ContentTypeID=1Thu, 05 Dec 2019 12:50:23 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6eb9cf18-8895-4674-99c1-2132f8135fefSimon<p>Take a look at <a href="https://devzone.nordicsemi.com/f/nordic-q-a/17837/dfu-how-to-split-and-send-the-firmware-image">this ticket</a>, and study the&nbsp;code links given by&nbsp;<a href="https://devzone.nordicsemi.com/members/andresovela">Andy</a>&nbsp;I think it will answer your questions.</p> <p>Best regards,</p> <p>Simon</p><div style="clear:both;"></div>