The Villages Aviation Club
Free FAA ADS_B Equipment Check

This FAA site automatically remotely checks the ADS_B equipment in your
airplane to determine if you are in compliance with the 2020 ADS_B
mandate.  It evaluates both ADS_B-IN and ADS_B-OUT.
You get an Email report discussing your equipment compliance.  

Below is the website to make the FAA request AND an example Email report
from the webmaster's airplane after making the request.   
Website to make FAA request
Example ADS_B Aircraft Operation Compliance Report
Example ADS_B Avionics Check