important

can i make hot scroller read from many categories

Yes, just put comma separated ID list

but this id is for article not for categoy

Open:

modules\mod_hot_scroller\mod_hot_scroller.xml

around line 104 you will find:

<field name="catid" type="category" extension="com_content" multiple="false" size="5" label="Category" description="A content category" />

change multiple="false" to multiple="true", then you can use CTRL to select multiple choices with mouse.

i did that but i get

Warning: Invalid argument supplied for foreach() in \xampp\htdocs\emad\misr\modules\mod_hot_scroller\mod_hot_scroller.php on line 137

$where_clause = "\n AND ( a.catid IN (". $catid .") )";

replace with:

$where_clause = "\n AND ( a.catid IN (". implode(",",$catid) .") )";