https://devzone.nordicsemi.com/f/nordic-q-a/85351/enabling-uart-2-with-hardware-flow-control-on-nrf9160dkHi! I am trying to enable a UART line for a peripheral that I want to interface with on a nRF9160. I am trying to set it up as an async or interrupt driven interface as the other device may have significant delays before CTS is asserted or responsesen-USTelligent Community 13Wed, 02 Mar 2022 15:18:41 GMThttps://devzone.nordicsemi.com/thread/355875?ContentTypeID=1Wed, 02 Mar 2022 15:18:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b7f41812-6687-4173-b21f-06d313bde745Vidar Berg<p>Thanks for the updates. As you found out, the callback function is not supported when using the interrupt API, but it&#39;s probably better to use the asynchronous APIs anyway.&nbsp; I should also add that the UART documentation has been revised in Zephyr upstream. It now has a more clear description of the different API functions: <a href="https://docs.zephyrproject.org/latest/reference/peripherals/uart.html">https://docs.zephyrproject.org/latest/reference/peripherals/uart.html</a></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/355856?ContentTypeID=1Wed, 02 Mar 2022 14:38:01 GMT137ad170-7792-4731-bb38-c0d22fbe4515:8ae6aa03-8e60-4e2e-b24a-33720e4147e7Oskar<p>UPDATE 2:<br />This seems to fix it.</p> <p>UPDATE:</p> <p>Disabling INTERRUPT_DRIVEN and enabling ASYNC_API seems to remove the error like so:</p> <pre>CONFIG_UART_INTERRUPT_DRIVEN=N<br />CONFIG_UART_ASYNC_API=y</pre><div style="clear:both;"></div>