Introduction: DIY-Fingerprint Key Security System

This application is useful for securing our day to day required keys(lock).Sometimes we are having some common keys like home,garage,parking in between two or more people .

There are a number of bio metric systems available in a market, it mainly includes face recognition, fingerprint recognition ,etc. for various applications like door lock (On/off)system, Attendance system, cupboard locking system, etc.

Step 1: TTL-51c3 Fingerprint Sensor

Here I am having one necessary and very useful application of a fingerprint sensor. I made a “Key security system using TTL-51c3 fingerprint sensor”. This kit is useful for the school, colleges, industries and anywhere, where maintaining the log of keys of important labs, cupboard is needed but is a little difficult. So here are a few steps by using this anyone can make their “DIY- FINGERPRINT KEY SECURITY SYSTEM.”

This sensor is easily available on amazon or any shopping sites at Rs.1500/-

Step 2: Step 1-Component Selection

Above image is of required material for buliding of this system,I made my own printed circuit board ,if you are not having options for printing circuit board then you can use any microcontroller from arduino series.

Download PCB files here

Step 3: Step 2-Circuit Diagram

Connect components as shown in above figure

Step 4: Step3-Programming the Board

Here is a code for enrolling the fingerprint and unlocking the lock by authorized user.

Add TTL fingerprint,I2c ,Sd card,Rtc libararies for arduino

Download code from here

Step 5: Step 4-Power Supplies

Connect 5V, 1 A power supply adapter to electricity board.(Here you will find Fingerprint sensor starts blinking),Give 12V,1 A supply to the solenoid(lock),Close the door. Mount the system on wall

Step 6: Step 5- Arrangements

For wall mounted key security system I used stainless steel box of 20cm X 20 Cm and door of acrylic and mounted component as shown in fig above.

Step 7: Step 6- Enrolling the Fingerprints

When all components are placed properly, you will find a message on the LCD display that says “Enroll Now”(for enrollment of the new user).

1. Then you have to press your finger on the fingerprint sensor properly.

2. Remove & place the same finger for 3 times on fingerprint

3. You will get the message “Enrollment done”.

Step 8: Step 7-Precautions

  • Do not provide power supply more than 5v,1A for PCB and 12 V 1 A for Solenoid.
  • Place the box properly with a nut bolt (given)to the wall and optimized height.