A lot of tutorials are about how to control Arduino through WiFi, but I need my Arduino to send information about motion sensor activity to a server. Is that possible?
Can you make Arduino Uno send information through a WiFi module to a server?
Yes, I can.
The simplest way is through an HTTP "GET" request. Every time you request a web page (and there are plenty of examples of that) you are sending data to the server to tell it both what web page to get (
/foo/bar.php) and what data to submit to that web page (
It's then up to you to craft that GET request, such as:
GET /foo/bar.php?baz=4 HTTP/1.1 Host: example.com Content-length: 0
and write the PHP web page (or whatever language you prefer to write web pages in) to do something meaningful with the "baz = 4" parameter.