Team-BHP - DIY: Arduino & RFID-based door unlocking

After a long time gap, I did another Do-It-Yourself project this time I made a Arduino Based RFID Door Unlocker.

It lets you unlock you door from even behind the windshield.
Simple project to deal with, it contains a Arduino Pro Mini with RC-522 as RFID Card Reader and a 5v Relay to trigger the door actuator.
When I first boot the Arduino it takes the 1st Card as Master Card which
takes it into programming mode, where you can Add or Remove Cards/Tags.

I was able to Read NFC Tag of my OnePlus One phone and saved it in Arduino and now If I don't have the Tag Around I can unlock my Car using my phone itself.
Later I found the RFID card issued to me from my employer also works fine and get saved. As the project is based on RC-522 module which is Read Only RFID Module, there's no change made to my Office Tag.

Delhi Metro Tokens can also be used but seems Metro Cards are of different frequency and were not read by RC-522 Module.

This is one real handy thing, as Tag is always on me while on the job and so I think now its least possible for me to get stranded if I lock my car keys inside.

Total money spent is around Rs.700/-

Don't have much pictures, and at this hour, they are not with me,
but a Video is made explaining the circuit in details.

Please do share this with your friends and family

https://youtu.be/xYsKRqzftkQ

Yes freedom, one can use ESP8266 but I had only one esp8266 which is currently used in my D.I.Y. weather station.
Its on test currently and sending Temprature, humidity, dew point, BMP to thingspeak and over couple of weekends I would use it to send automated weather data to Wunderground network.

Coming back to point, This Car door unlock is making people give that surprised look, office colleagues have lost few bets (no money involved) and people who notice me around the city give that strange look to my old car.