Figure 1 - Your own RFid Lock set (click to enlarge)
At least once in our lives we have come across some kind of RFid locks in homes, offices, elevators or hotels. Some of you may have been inspired to build your own version of it for your home or as a final product. We will show you how you can do this in a blink of an eye. Using PIC-Ready1 with PIC18F4520, RFid reader, Relay 4 board, along with EasyInput and EasyBuzz we have created a RFid lock that controls 4 separate relays with RFid cards. And it will cost you less than $100!
Before you can use it, you must program the board to recognize your RFid cards, and assign them to each relay separately.
- Bring 5V to the input pins on PORTA associated with relays. You can do this using EasyInput board
- Reset PIC-Ready1 board to enter programming mode. Buzzer will signal that programming mode is enabled.
- One-by-one, program the RFid card for each relay by swaping it over RFid reader when a relay LED turns on.
- After you are finished, bring inputs on PORTA to GND and reset the board to enter normal mode.
- By swapping the appropriate card over the RFid reader, associated relay will turn on for 2 seconds, accompanied by a sound signalization.
- Buzzer will signal if the card is not recognized.
Figure 2 - RFid Lock schematics (click to enlarge)
Source code of this project is provided for free, so you can modify it to suit your needs. Since PIC18F4520 comes preprogrammed with free UART Bootloader, you won’t have to spend a dollar more on external programmers. You can modify the project as much as you like, and expand this basic functionality with your own implementation ideas.
