https://test-devzone.nordicsemi.com/f/nordic-q-a/88014/nrf52840-using-two-uart-simultaneouslyHi, I&#39;m using two UARTs on nRF52840 with SDK17.1. My issue is both UART works individually until they receive messages at the same time. Both of them receive an RX overrun event. In my UART RX interrupt handler, I&#39;m simply move a byte into a bufferen-USTelligent Community 13 Non-ProductionWed, 18 May 2022 08:47:59 GMThttps://test-devzone.nordicsemi.com/thread/368236?ContentTypeID=1Wed, 18 May 2022 08:47:59 GMT137ad170-7792-4731-bb38-c0d22fbe4515:8ad20166-e679-41ae-bf2c-6bf3203558a6user112915<p>whoops, I think it&#39;s a totally different problem. I&#39;ll dig deeper.</p><div style="clear:both;"></div>https://test-devzone.nordicsemi.com/thread/368180?ContentTypeID=1Wed, 18 May 2022 05:28:56 GMT137ad170-7792-4731-bb38-c0d22fbe4515:0ff6dc50-0472-4fd0-a5e1-530b4368fd1cuser112915<p>some update, only UART0 has an overrun error, UART1 doesn&#39;t. I tried to disable all interrupt in my UART0 RX interrupt handler but it doesn&#39;t fix the issue.</p><div style="clear:both;"></div>