https://devzone.nordicsemi.com/f/nordic-q-a/80692/uart-921600bit-s-why-so-slowDear Sirs, In my current project I use nRF52 and external ADC. I have to send 14 Bytes each 500us using UART to PC. It is only one way connection where nRF52840 is transmitter. As I mentioned before, data amount is 14 Bytes and frequency is 2kHzen-USTelligent Community 13Sat, 16 Oct 2021 11:37:15 GMThttps://devzone.nordicsemi.com/thread/334438?ContentTypeID=1Sat, 16 Oct 2021 11:37:15 GMT137ad170-7792-4731-bb38-c0d22fbe4515:245c6109-35ed-4bc9-9487-ab7d175a9cdbmtimm<p>Thank you Simonr,</p> <p>I have switched to UARTE and now transfer total time of 14 Bytes is ~170us. (using APP_UART was ~302us). So difference is huge.</p> <p>Could you please clarify what is the purpose of using APP_UART driver? Has it any advantages / pros comparing to UARTE? In my opinion it should be mark as&nbsp;not recommended or deprecated.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/334362?ContentTypeID=1Fri, 15 Oct 2021 12:49:07 GMT137ad170-7792-4731-bb38-c0d22fbe4515:bf88aad2-3772-4e35-8b70-6046a290d3c6Simonr<p>Hi</p> <p>It seems like the reason it&#39;s so slow is that you only write one byte at a time, making the device wait for each byte to be received before sending the next. My suggestion is to use <a href="https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.nrf52832.ps.v1.1%2Feasydma.html&amp;anchor=easydma">EasyDMA </a>to provide a dedicated channel for reading data from RAM to the peripheral at the same time as a second channel is dedicated for writing data to the RAM from the peripheral.</p> <p>Best regards,</p> <p>Simon</p><div style="clear:both;"></div>