https://devzone.nordicsemi.com/f/nordic-q-a/85894/error-when-trying-to-flash-application-onto-nrf52840---fatal-error-nrfjprog---ids-did-not-find-a-board-is-the-board-connected1) I have set up the Zephyr development environment by following the instructions at https://docs.zephyrproject.org/latest/getting_started/index.html 2) I am able to build the &quot;blinking sample&quot; successfully using the command west build -p auto -ben-USTelligent Community 13Thu, 17 Mar 2022 07:25:55 GMThttps://devzone.nordicsemi.com/thread/358530?ContentTypeID=1Thu, 17 Mar 2022 07:25:55 GMT137ad170-7792-4731-bb38-c0d22fbe4515:384cb7e0-e7c6-4a12-99bb-07e73f5aba7aMarte Myrvold<p>Hi,</p> <p>You cannot use nrfjprog to program the dongle unless you are using an external debugger as the dongle does not have an onboard debugger. When programming the dongle through the built-in USB bootloader you can either use the Programmer app from <a href="https://www.nordicsemi.com/Software-and-Tools/Development-Tools/nRF-Connect-for-desktop">nRF Connect for Desktop</a>&nbsp;and program it as described here: <a href="https://infocenter.nordicsemi.com/topic/ug_nc_programmer/UG/nrf_connect_programmer/ncp_programming_dongle.html">Programming the nRF52840 Dongle</a>,&nbsp;or you can use nrfutil by following the steps in&nbsp;<a href="https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/boards/arm/nrf52840dongle_nrf52840/doc/index.html#option-1-using-the-built-in-bootloader-only">Option 1: Using the Built-In Bootloader Only</a>.</p> <p>Best regards,</p> <p>Marte</p><div style="clear:both;"></div>