Working of RFID and Keypad based Door lock and Alert System using Arduino
- On scanning the wrong tag or on entering the wrong password, it will send us an alert.
- On scanning the right tag and on entering the right password, it will send us a confirmation message that the door has opened.
- You can halt the system by sending ‘close’ message to Arduino and it will only go back to normal mode when you will send the ‘open’ message to Arduino. During halt time, it won’t scan any tags and it will only look for messages.
Circuit Explanation
The RFID reader communicates with the Arduino through the SPI protocol and different Arduino boards have different SPI pins.
To test if the RFID reader is working properly or not, upload the “dumpinfo” from the examples in the Arduino and see if it is showing the information of the tags on the serial monitor or not.
The I2C LCD communicates with the Arduino through the I2C protocol. Different Arduino boards have different I2C pins. The I2C pins on Arduino Uno and Arduino Nano are A4, A5.
Next connect the keypad with Arduino. The 4X4 keypad has 8 connections but we don’t require the last column of keypad. We only require numbers for the password. So we won’t use the last pin of keypad which is for fourth column. You can also use 4X3 keypad instead of 4X4 keypad.