Well now this automatic recent post slider have a testing tool where you can enter your blog URL and see how Dynamically it generate a slider from your blog's feed. This tools have other basic options like Image Size, Max Item, Label (you can specify a label to generate slider from. Though it is optional). Check out the Live Testing Tool.
How to Add feature Post SliderWidgets In Blogger
Go to Layout > click the add gadget link the sidebar area and select 'HTML/Javascript' gadget from the popup window.
Add the code below inside the empty box.
"<style type="text/css">
ul.featured-widget-list,ul.featured-widget-list li{margin:0;padding:0;list-style:none;position:relative }ul.featured-widget-list li{display:none}ul.featured-widget-list li:nth-child(1){display:block;line-height:0}ul.featured-widget-list img{border:0;width:100%;height:auto}ul.featured-widget-list .featuredbg{width:100%;height:100%;position:absolute;z-index:2;left:0;top:0;opacity:.6;background-image:url(https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh93woSBJJqPJTxY5Ai5eDRnLotkwc2b-YjxeEFFYLaIU0yeqm5VSWNs7dUFHUkoPW3rFA3LRSzSXWtB-6pxWGydJONG7j0eKBu66cUUB00QO5CvSDxkhyvEBDoeZCpYRf6RItIB6Y8JQw/s400/overlay-bg.png);background-position:0% 100%;background-repeat:repeat-x}ul.featured-widget-list .featuredbg:hover{opacity:.1}ul.featured-widget-list h5{position:absolute;left:0;right:0;text-align:center;bottom:10px;z-index:2;color:#fff;margin:0;text-transform: capitalize;padding:10px 20px;line-height:1.9em;letter-spacing:0.3px;font: 600 16px 'Abel', sans-serif;overflow:hidden}ul.featured-widget-list li:hover h5{bottom:30px}ul.featured-widget-list .featured-meta{font: 11px 'Abel', sans-serif;letter-spacing:0.3px;position:absolute;bottom:0;left:0;right:0;text-align:center;z-index:2;color:#fff;opacity:0}ul.featured-widget-list h5, ul.featured-widget-list .featured-meta {-webkit-transition: all 0.3s;-moz-transition: all 0.3s;-o-transition: all 0.3s;transition: all 0.3s;}ul.featured-widget-list li:hover .featured-meta{bottom:20px;opacity:1}.feat-buttons{position:absolute;top:50%;left:0;z-index:5;width:100%}
.feat-buttons a{text-indent:-9999px;margin:0 7px;width:15px;height:15px;padding:5px;background:#000;-ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=60)";filter: alpha(opacity=60);-moz-opacity:0.6;-khtml-opacity:0.6;opacity:0.6;position:relative;-webkit-border-radius: 50%;-moz-border-radius: 50%;border-radius: 50%;}.feat-prev{float:left;}.feat-next{float:right;}.feat-buttons a.feat-prev::before, .feat-buttons a.feat-next::before{content:"";width:0;height:0;border-width:6px 7px;border-style:solid;border-color:transparent #fff transparent transparent;position:absolute;top:50%;margin-top:-6px;margin-left:-11px;left:50%}
.feat-buttons a.feat-next::before{border-color:transparent transparent transparent #fff;margin-left:-3px}
</style>
<div id="featuredbwidget"></div>
<link href='https://fonts.googleapis.com/css?family=Abel' rel='stylesheet' type='text/css'/>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.0/jquery.min.js" type="text/javascript"></script>
<script type='text/javascript'>
//<![CDATA[
featuredbwidget({
listURL:"https://chauhanalltech.blogspot.com/",
featuredNum:9,
listbyLabel:false,
feathumbSize:350,
interval:3000,
autoplay:true,
featuredID:"#featuredbwidget"
});
function featuredbwidget(a){(function(e){var h={listURL:"",featuredNum:3,featuredID:"",feathumbSize:300,interval:5000,autoplay:false,loadingFeatured:"nextfeatured",pBlank:"https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgyTNjmTrAeZC7pGrfYjZ0smCcaABLpD-2KMapl-g7U9YiwapGQg8BX67h6ZoQGyVoxfpY-7RyHO4uNiYZk5jqfqwV2Ln1jZJiV4Vnwihv1zPjjWXJiA4fOxcDfZVLm9UpX-haEEtm-YGQ/s500/no-image.png",byMonth:["Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"],listbyLabel:false};h=e.extend({},h,a);var g=e(h.featuredID);var d=h.featuredNum*200;g.html('<div class="featslider"><ul class="featured-widget-list"></ul><div class="feat-buttons"><a href="#" class="feat-prev">Prev</a><a href="#" class="feat-next">Next</a></div></div>');var f=function(w){var q,k,m,u,x,p,t,v,r,l="",s=w.feed.entry;for(var o=0;o<s.length;o++){for(var n=0;n<s[o].link.length;n++){if(s[o].link[n].rel=="alternate"){q=s[o].link[n].href;break}}if("media$thumbnail" in s[o]){u=s[o].media$thumbnail.url.replace(/\/s[0-9]+\-c/g,"/s"+h.feathumbSize+"-c")}else{u=h.pBlank.replace(/\/s[0-9]+(\-c|\/)/,"/s"+h.feathumbSize+"$1")}k=s[o].title.$t;r=s[o].published.$t.substring(0,10);m=s[o].author[0].name.$t;x=r.substring(0,4);p=r.substring(5,7);t=r.substring(8,10);v=h.byMonth[parseInt(p,10)-1];l+='<li><a href="'+q+'"><div class="featuredbg"></div><img class="featuredthumb" src="'+u+'"/><h5>'+k+'</h5></a><div class="featured-meta"><span class="fdate"><span class="fday">'+t+'</span> <span class="fmonth">'+v+'</span> <span class="fyear">'+x+'</span></span> - <span class="fauthor">'+m+"</span></div></li>"}e("ul",g).append(l).addClass(h.loadingFeatured)};var c=function(){e(h.featuredID+" .feat-next").click()};var b=function(){e.get((h.listURL===""?window.location.protocol+"//"+window.location.host:h.listURL)+"/feeds/posts/summary"+(h.listbyLabel===false?"":"/-/"+h.listbyLabel)+"?max-results="+h.featuredNum+"&orderby=published&alt=json-in-script",f,"jsonp");setTimeout(function(){e(h.featuredID+" .feat-prev").click(function(){e(h.featuredID+" .featslider li:first").before(e(h.featuredID+" .featslider li:last"));return false});e(h.featuredID+" .feat-next").click(function(){e(h.featuredID+" .featslider li:last").after(e(h.featuredID+" .featslider li:first"));return false});if(h.autoplay){var i=h.interval;var j=setInterval(c,i);e(h.featuredID+" .featslider li:first").before(e(h.featuredID+" .featslider li:last"));e(h.featuredID+" .featslider").hover(function(){clearInterval(j)},function(){j=setInterval(c,i)})}e("ul",g).removeClass(h.loadingFeatured)},d)};e(document).ready(b)})(jQuery)};
//]]>
</script>"
Now replace "https://chauhanalltech.blogspot.com/" with your blog URL.
Add the number of post to display in the slider.
if you want to display posts by category /labels such as the tag fashion , it will be written as listbyLabel:Fashion"
the size or dimension of the image in pixels
time taken to change the slides position in milliseconds
replace tru with false if you don't want the slides to change automatically
