Circuit Lake

Electronic Project and Circuit Collection

RFID Car Lock and Unlock

10/02/2012 Category: Arduino, Remote, Wireless

Many new cars have key less entry options to lock and unlock the door. It makes your life easier. But, if you have old car and want to add this feature, you can make your own Wireless Car Lock and Unlock based on RFID.

Mathew has built a nice RFID Car Lock and Unlock for his old car. The project uses Arduino Pro as main processor and Parallax RFID reader (Low-cost module for reading passive RFID EM4100 family transponder tags). Arduino read data RFID reader and control switching circuit connected to in parallel with the door lock/unlock switch. LM7805 is used to drop voltage 12V from car battery to 5V. The voltage regulator output then sent to power both the Arduino, and the Parallax RFID readers.

DIY RFID car locker

How it works?
When you walk up to car and the RFID readers scan transponder tags and then send the tags data serially to the microcontroller. The MCU verifies whether the tag has the right code to unlock the car or not. If the code is valid the Arduino sends a signal to the switching circuit to unlock the car. But, If the code is invalid the tag is ignored and nothing happen. After 25 second, the MCU locks the car automatically.