Learn how to use the sensor module, I2C LCD, and Arduino UNO development board to make a fingerprint-controlled door lock.
In this article, I will show you how to make a smart door lock using a fingerprint sensor and Arduino UNO. The door lock will open only when the fingerprint scanned by the user matches the fingerprint recorded on the system. If the fingerprint entered is wrong, the door will remain closed.
Required hardware
● Arduino UNO development board
● Fingerprint sensor module
● I2C LCD display
● Relay module
● Door lock
● 7 to 12V power supply
● Jumper cable
Circuit diagram and description
First, connect the fingerprint sensor to the Arduino UNO development board. Please make sure that the fingerprint sensor you use can work with Arduino through serial communication.
The default pins for serial communication on Arduino UNO are pin 0 (RDX) and pin 1 (TXD) of the board, but we will use other pins for serial communication. In this article, we will use the SoftwareSerial library in the code.
The following are the connections required between the fingerprint sensor and the UNO development board:
Then connect the I2C LCD module to UNO. The connection is as follows:

Then, connect the relay module to the Arduino UNO as shown in the circuit diagram below.

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Fingerprint door lock circuit diagram.

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To control the door lock, you need a 7 to 12V battery-I used three 18650 batteries.
For more information, please refer to the following link: https://www.yiboard.com/thread-1113-1-1.html