https://devzone.nordicsemi.com/f/nordic-q-a/73496/during-uart-communication-a-delay-of-about-10us-occurs-between-charactersHello. I am writing a program using an example called ble_app_uart. While using the printf function, the output is output with a delay of 10us between characters and characters. Can&#39;t you get rid of this delay? Additionally, I gave a baud rate ofen-USTelligent Community 13Tue, 06 Apr 2021 14:36:00 GMThttps://devzone.nordicsemi.com/thread/303229?ContentTypeID=1Tue, 06 Apr 2021 14:36:00 GMT137ad170-7792-4731-bb38-c0d22fbe4515:e13b6ae9-e249-4218-b22c-1148b5051684Karl Ylvisaker<p>Hello,</p> [quote user=""]No results for about 4 days.[/quote] <p>Thank you for your patience with this. The national Easter holiday has just concluded here in Norway, and we are now back in office.</p> [quote user=""]While using the printf function, the output is output with a delay of 10us between characters and characters.[/quote] <p>The retargeted <em>printf&nbsp;</em>is just calling app_uart_put which uses a FIFO buffer to do bytewise transfers, this might be why you are seeing one-and-one byte being transferred.<br />Could you try to use the <a href="https://infocenter.nordicsemi.com/index.jsp?topic=%2Fsdk_nrf5_v17.0.2%2Fgroup__nrfx__uart.html&amp;anchor=ga96d8dfc8c56ebb4c8954ce45ecdc5c5c">nrfx_uart_tx</a>&nbsp;function directly, with an array larger than 1, and see if you then get rid of the 10us delay.<br /><br />Best regards,<br />Karl</p><div style="clear:both;"></div>