https://devzone.nordicsemi.com/f/nordic-q-a/3731/inital-uart-data-always-show-bad-data-via-jlink-cdcmy code shows here: github.com/.../main.c uart_init(); printf(&quot;\r\n\r\n&quot;); printf(&quot;\r\n __DEBUGGING__\r\n&quot;); every time my app started, it always shows corrupted data ( how to name the data ? ) like this �H�HX�E U%9}}5 what&#39;s theen-USTelligent Community 13Wed, 17 Sep 2014 19:07:33 GMThttps://devzone.nordicsemi.com/thread/13531?ContentTypeID=1Wed, 17 Sep 2014 19:07:33 GMT137ad170-7792-4731-bb38-c0d22fbe4515:c5c31071-ddb8-4276-888c-cb302c368cd4Nikita<p>Try to use one of the example projects and add simple_uart data send to it. If you will still get your data corrupted then it&#39;s hardware problem and you need to check your board.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/13535?ContentTypeID=1Wed, 17 Sep 2014 18:36:08 GMT137ad170-7792-4731-bb38-c0d22fbe4515:81db128e-931f-4330-90a0-90cb248ad005sprhawk<p>With NRF51822 EK, via JLink CDC</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/13534?ContentTypeID=1Wed, 17 Sep 2014 16:52:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:87ba5026-d338-4a10-aa8c-e035d7ba5491syntroniks<p>How are you connecting the uart to the PC? I use TTL serial to USB converter chips usually. What are you using? Maybe it has an internal buffer or hardware issue</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/13533?ContentTypeID=1Wed, 17 Sep 2014 16:04:38 GMT137ad170-7792-4731-bb38-c0d22fbe4515:75a11d75-83f3-465b-88f1-c3c72412dc16sprhawk<p>not the baud rate, the output is correct later.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/13530?ContentTypeID=1Wed, 17 Sep 2014 16:04:10 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d3c6f057-beff-482d-85f1-e1e2a66c39a6sprhawk<p>normal data is printed in my timer function, less than a second</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/13532?ContentTypeID=1Thu, 11 Sep 2014 14:56:57 GMT137ad170-7792-4731-bb38-c0d22fbe4515:e43baec1-7567-40e7-8dd7-5970032feb84syntroniks<p>Your baudrate is set wrong in your viewing application :&gt;</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/13529?ContentTypeID=1Wed, 10 Sep 2014 10:30:18 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d39b3f25-9d6b-4b18-a9ea-a286919d81e0Nikita<p>You have corrupted data only in the beginning and after a while it start to print normal data? Can you trace at what point you start to get normal data (position in code or elapsed time)?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/13528?ContentTypeID=1Wed, 10 Sep 2014 10:22:47 GMT137ad170-7792-4731-bb38-c0d22fbe4515:8fed01e7-eab2-4ffe-8943-013620645519sprhawk<p>printf is defined in stdio, it called _write is defined here: <a href="https://github.com/sprhawk/nrf51822-first-fw/blob/d3beb5f597666108b229a6f8f7eb30608f8b976c/uart.c">github.com/.../uart.c</a></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/13527?ContentTypeID=1Wed, 10 Sep 2014 10:19:18 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6c53f465-60b8-4687-ba43-555258e3784dNikita<p>No, show printf() function source code.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/13526?ContentTypeID=1Wed, 10 Sep 2014 10:06:45 GMT137ad170-7792-4731-bb38-c0d22fbe4515:be2c12b6-d8f5-4cc9-bc2a-c43ac50eedb5sprhawk<p>just show in the code. \r\n is the new line code for serial terminal</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/13525?ContentTypeID=1Thu, 04 Sep 2014 13:48:18 GMT137ad170-7792-4731-bb38-c0d22fbe4515:2c54a5c5-b1a1-483d-b723-c507738b5b73Nikita<p>What&#39;s inside printf()?</p><div style="clear:both;"></div>