https://devzone.nordicsemi.com/f/nordic-q-a/77489/nrf9160-custom-board-uart0-debug-printk-and-program-use-secure-faultShalom! I have a custom nRF9160 board with uart0 connected to the outside world by RS232. I set the uart0 as the printk() debug output. I also need to write and read binary data through uart0. When using the nRF9160-DK I was able to configure everythingen-USTelligent Community 13Thu, 15 Jul 2021 16:46:53 GMThttps://devzone.nordicsemi.com/thread/320326?ContentTypeID=1Thu, 15 Jul 2021 16:46:53 GMT137ad170-7792-4731-bb38-c0d22fbe4515:9cf7a15b-fbe4-403f-a83b-aa18acf87260Simon<p>Try to adding the secure version of your board to&nbsp;<a href="https://github.com/nrfconnect/sdk-nrf/tree/v1.6.0/samples/spm/boards">https://github.com/nrfconnect/sdk-nrf/tree/v1.6.0/samples/spm/boards</a>&nbsp;</p> <p>E.g. if your board is called &quot;myboard_nrf9160&quot;, create the file &quot;<span>myboard_nrf9160.overlay</span>&quot; (not&nbsp;<span>myboard_nrf9160ns.overlay</span>) with the following content:&nbsp;<a href="https://github.com/nrfconnect/sdk-nrf/blob/v1.6.0/samples/spm/boards/thingy91_nrf9160.overlay">https://github.com/nrfconnect/sdk-nrf/blob/v1.6.0/samples/spm/boards/thingy91_nrf9160.overlay</a></p> <p>Best regards,</p> <p>Simon</p><div style="clear:both;"></div>