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<?xml-stylesheet type="text/xsl" href="https://devzone.nordicsemi.com/cfs-file/__key/system/syndication/rss.xsl" media="screen"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/" xmlns:wfw="http://wellformedweb.org/CommentAPI/" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>nRF51422 - UART</title><link>https://devzone.nordicsemi.com/f/nordic-q-a/13421/nrf51422---uart</link><description>When I using the UART port, if I float the port after init the UART it will restart the code, is it need a external pull-up resistor? How about the value?</description><dc:language>en-US</dc:language><generator>Telligent Community 13</generator><lastBuildDate>Fri, 22 Apr 2016 12:02:19 GMT</lastBuildDate><atom:link rel="self" type="application/rss+xml" href="https://devzone.nordicsemi.com/f/nordic-q-a/13421/nrf51422---uart" /><item><title>RE: nRF51422 - UART</title><link>https://devzone.nordicsemi.com/thread/51228?ContentTypeID=1</link><pubDate>Fri, 22 Apr 2016 12:02:19 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:4cc50fa3-e076-4258-9d51-80f216a3071a</guid><dc:creator>Ole Bauck</dc:creator><description>&lt;p&gt;You are probably getting an APP_UART_COMMUNICATION_ERROR event which will by default call the APP_ERROR_HANDLER which will reset the chip by default (if DEBUG is not defined).&lt;/p&gt;
&lt;p&gt;You can either handle the communcation error differently or configure RX with an internal pull-up:&lt;/p&gt;
&lt;p&gt;NRF_GPIO-&amp;gt;PIN_CNF[RX_PIN_NUMBER] |= (GPIO_PIN_CNF_PULL_Pullup &amp;lt;&amp;lt; GPIO_PIN_CNF_PULL_Pos);&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>