<?xml version="1.0" encoding="UTF-8" ?>
<?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>time stamp accuracy problem</title><link>https://devzone.nordicsemi.com/f/nordic-q-a/98324/time-stamp-accuracy-problem</link><description>Hi, 
 My time stamp is calculated by RTC counter.And I found that the time stamp was about 12s faster when comparing nrf-connect logs after a day. 
 Here is the configuration I set up.The accuracy of the external crystal oscillator is 20ppm. And I use</description><dc:language>en-US</dc:language><generator>Telligent Community 13</generator><lastBuildDate>Mon, 03 Apr 2023 13:12:05 GMT</lastBuildDate><atom:link rel="self" type="application/rss+xml" href="https://devzone.nordicsemi.com/f/nordic-q-a/98324/time-stamp-accuracy-problem" /><item><title>RE: time stamp accuracy problem</title><link>https://devzone.nordicsemi.com/thread/418857?ContentTypeID=1</link><pubDate>Mon, 03 Apr 2023 13:12:05 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:8508544c-b7af-4b8c-8141-8b82a3dc9e6b</guid><dc:creator>Victor A</dc:creator><description>&lt;p class="_tgt transPara grammarSection"&gt;&lt;span class="transSent" data-group="0-0"&gt;&lt;span&gt;Hardware: The chip is 52832, the low-frequency crystal frequency is 32.768kHz, and the crystal precision is &amp;plusmn;20ppm &amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p class="_tgt transPara grammarSection"&gt;&lt;span class="transSent" data-group="1-0"&gt;&lt;span&gt;Our application is to make a second level timestamp (Unix timestamp)function,&amp;nbsp;it can synchronize the time through the phone.&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;span class="transSent" data-group="1-1"&gt;&lt;span&gt; I start a 1-second app timer and increment the timestamp by 1s as&amp;nbsp;every second&amp;nbsp;time out.&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;span class="transSent" data-group="1-2"&gt;&lt;span&gt; The code is as follows &amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p class="_tgt transPara grammarSection"&gt;&lt;span class="transSent" data-group="2-0"&gt;&lt;span&gt;&amp;nbsp;&lt;img style="max-height:240px;max-width:320px;" alt=" " src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/pastedimage1680526826468v1.png" /&gt;&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p class="_tgt transPara grammarSection"&gt;&lt;span class="transSent" data-group="3-0"&gt;&lt;span&gt;Test procedure: Synchronize the time at a point where the phone time is consistent with the firmware timestamp.&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;span class="transSent" data-group="3-1"&gt;&lt;span&gt; After running 9 hours, the firmware timestamp is read from the mobile phone. The time when the firmware is read is displayed on the log. The firmware time is 11s faster than that of the mobile phone.&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p class="_tgt transPara grammarSection"&gt;&lt;span class="transSent" data-group="3-1"&gt;&lt;span&gt;&lt;img style="max-height:240px;max-width:320px;" alt=" " src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/pastedimage1680527425807v4.jpeg" /&gt;&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p class="_tgt transPara grammarSection"&gt;&lt;span class="transSent" data-group="3-1"&gt;&lt;span&gt;&lt;img style="max-height:240px;max-width:320px;" alt=" " src="https://devzone.nordicsemi.com/cfs-file/__key/communityserver-discussions-components-files/4/pastedimage1680527404978v3.jpeg" /&gt;&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: time stamp accuracy problem</title><link>https://devzone.nordicsemi.com/thread/418623?ContentTypeID=1</link><pubDate>Fri, 31 Mar 2023 13:33:29 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:d3088761-eb27-4f52-877d-c35c19ef5d7c</guid><dc:creator>Kazi Afroza Sultana</dc:creator><description>&lt;p&gt;&lt;span&gt;Hello,&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;&amp;#39;&amp;#39;And I found that&amp;nbsp;&lt;/span&gt;&lt;span&gt;the time stamp was about 12s faster when comparing nrf-connect logs after a day.&amp;#39;&amp;#39; Could you please elaborate a bit detail&amp;nbsp;about this comparison?&amp;nbsp;&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;Thanks.&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;BR&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;Kazi&lt;/span&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>