https://devzone.nordicsemi.com/f/nordic-q-a/101686/a-question-mark-byte-getting-printed-in-uart-tx-lineI am seeing a single ? byte printed to the TX line upon UART initialization. It&#39;s only printed once so I doubt if it&#39;s related to baud rate. When I run in debug mode, I don&#39;t see it happen but I when I run the firmware, it does. I was wondering if iten-USTelligent Community 13Tue, 18 Jul 2023 08:56:26 GMThttps://devzone.nordicsemi.com/thread/436930?ContentTypeID=1Tue, 18 Jul 2023 08:56:26 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6036f357-a5cf-4179-8dde-f5d1b2e8ce1bSigurd Hellesvik<p>Do you see the same behavior with the <a href="https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.1.0/libuarte_example.html?cp=9_1_4_6_17">libuarte sample</a>&nbsp; as you do for the UART example?</p> <p>So you have connected the lines to the DK on once side.<br />Have you connected them to something else on the other side? (in addition to the logic analyzer)</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/436616?ContentTypeID=1Mon, 17 Jul 2023 03:45:13 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f264a69d-6973-463a-b35c-ab29a8da10eemorpho<p>I am using the RX/TX pins already defined in pca10056.h. I have already attached a screenshot that shows I see 255 initially. Please assign this ticket to someone who can help or provide a better support.&nbsp;</p> <pre>#define RX_PIN_NUMBER 8 #define TX_PIN_NUMBER 6</pre><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/436466?ContentTypeID=1Fri, 14 Jul 2023 12:05:57 GMT137ad170-7792-4731-bb38-c0d22fbe4515:3ca40b6d-2162-4828-9977-bdb6054fb52aSigurd Hellesvik<p>In this case, you should be able to see something on your lines.</p> <p>Which pins are you connected to?</p> <p>Double check that your cables work wiht a multimeter.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/436307?ContentTypeID=1Thu, 13 Jul 2023 15:09:10 GMT137ad170-7792-4731-bb38-c0d22fbe4515:53c31e78-7d6a-4504-b555-a1abfe20fb2dmorpho<p>Yes</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/436231?ContentTypeID=1Thu, 13 Jul 2023 11:40:00 GMT137ad170-7792-4731-bb38-c0d22fbe4515:39a556d7-d4ef-4f93-8d3e-38fcb0c4f17fSigurd Hellesvik[quote user="morpho"]nRF52840 as is[/quote] <p>Do you mean nRF52840DK?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/435793?ContentTypeID=1Tue, 11 Jul 2023 15:55:49 GMT137ad170-7792-4731-bb38-c0d22fbe4515:1d7dd1fc-c1e3-4e27-89ef-eae1a6429abdmorpho<p>I tried the&nbsp;<a href="https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.1.0/uart_example.html">UART</a>&nbsp;example.</p> <p>1. I see \r as the first byte in logic analyzer and not in terminal</p> <p>2. I don&#39;t see any output being echoed back to console to what I type in. I have set up my tty port at 115200 as well</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/435705?ContentTypeID=1Tue, 11 Jul 2023 11:55:07 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f5f0387e-e1dd-42a0-a960-57884e602cb7Sigurd Hellesvik<p>Can you try our <a href="https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.1.0/libuarte_example.html?cp=9_1_4_6_17">libuarte sample</a> and see if that gives you UART output?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/435531?ContentTypeID=1Mon, 10 Jul 2023 14:13:37 GMT137ad170-7792-4731-bb38-c0d22fbe4515:9593e262-9d4a-497d-967b-d2f97f6f8c9bmorpho<p>nRF5_SDK_17.1.0_ddde560</p> <p>Custom Firmware for UART</p> <p>nRF52840 as is</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/435456?ContentTypeID=1Mon, 10 Jul 2023 11:02:33 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f145ba6c-a21c-40f9-8dde-36e4a1423033Sigurd Hellesvik<p>Hi,</p> <p>Which version of the SDK do you use?</p> <p>Do you use custom firmware or one of our samples?</p> <p>Do you use custom hardware or one of our Developement Kits?</p> <p>Regards,<br />Sigurd Hellesvik</p><div style="clear:both;"></div>