SoftDevice Controller: 100% connection establishment failure (HCI 0x3E) with SKY66112-11 PA activehttps://devzone.nordicsemi.com/f/nordic-q-a/129216/softdevice-controller-100-connection-establishment-failure-hci-0x3e-with-sky66112-11-pa-activeTitle: SoftDevice Controller: 100% connection establishment failure (HCI 0x3E) with SKY66112-11 PA active Hi Everyone, I am working on the following development project for production. We are using the Fanstel USB840X dongle for long-range communicationen-USTelligent Community 13Mon, 21 Sep 2026 07:09:19 GMTRE: SoftDevice Controller: 100% connection establishment failure (HCI 0x3E) with SKY66112-11 PA activehttps://devzone.nordicsemi.com/thread/571377?ContentTypeID=1Mon, 21 Sep 2026 07:09:19 GMT137ad170-7792-4731-bb38-c0d22fbe4515:1b869f82-a55d-4b7c-b5ac-37f23d45bf7bH&#229;kon Alseth<p>Hi,</p> <p>&nbsp;</p> [quote user=""]nRF Connect SDK v2.7.0, board target nrf52840dongle_nrf52840, application based on the hci_usb sample[/quote] <p>The dongle uses certain GPIOs for other purposes, for instance P0.17 for UART:</p> <p><a href="https://github.com/nrfconnect/sdk-zephyr/blob/v3.6.99-ncs2/boards/nordic/nrf52840dongle/nrf52840dongle_nrf52840-pinctrl.dtsi#L10">https://github.com/nrfconnect/sdk-zephyr/blob/v3.6.99-ncs2/boards/nordic/nrf52840dongle/nrf52840dongle_nrf52840-pinctrl.dtsi#L10</a></p> <p>&nbsp;</p> <p>Try either disabling serial or redefining the uart0 pinctrl.</p> <p>&nbsp;</p> <p>I would in general recommend that you scope your pins to verify that they work as expected.</p> <p>&nbsp;</p> <p>Kind regards,</p> <p>Håkon</p><div style="clear:both;"></div>