Simple Arduino controlled RFID electric door strike. I'm using a MASTER_ADD key to add keys, and separate MASTER_DELETE key to delete all keys from the arduino EEPROM.
Next steps would be to use mqtt to communicate with a Raspberry PI SQL server that will hold a central key database. That would synchronize the authorized key list for all RFID doors in the house. If you can't run cat5 cables to all your doors, the sparkcore (http://www.sparkdevices.com/) will be the perfect solution once it's released.
