https://devzone.nordicsemi.com/f/nordic-q-a/44475/bring-up-the-serial-example-on-pca10056-boardI try to active the serial example in the nordic folder nRF5_SDK_15.2.0_9412b96. When using RX_PIN_NUMBER 8, TX_PIN_NUMBER 6, CTS_PIN_NUMBER 7, RTS_PIN_NUMBER 5, HWFC true. I use the PCA10056 board. 1. Is the standard setting in the example demenden-USTelligent Community 13Wed, 06 Mar 2019 10:48:46 GMThttps://devzone.nordicsemi.com/thread/174507?ContentTypeID=1Wed, 06 Mar 2019 10:48:46 GMT137ad170-7792-4731-bb38-c0d22fbe4515:db5fb7e8-029f-449b-b242-3a8a763d4058awneil[quote userid="76576" url="~/f/nordic-q-a/44475/bring-up-the-serial-example-on-pca10056-board"] I trace the line and found it enter U5&nbsp;FSA2466UMX which control by U2&nbsp;ATSAM3U2CA-AU[/quote] <p>That&#39;ll be the on-board JLink.</p> <p>That includes a UART-to-USB converter, which connects the nRF52&#39;s UART to a virtual COM port on the PC.</p> <p>The demo is intended to work with a terminal program on the PC, via the virtual COM port.</p> <p>IIRC, it <em>does</em> require hardware flow control.</p> <p>You should get this working first.</p> <p>Then, if you want to connect direct to the <span>nRF52&#39;s&nbsp;</span>UART, you need to identify some free &amp; accessible pins ...</p><div style="clear:both;"></div>