Fingerprint-Based Door Unlock

People who forget their keys before leaving their homes will never again face face a situation of waiting for someone else to open the door.

IntermediateWork in progress4 hours1,736

Things used in this project

Hardware components

Texas Instruments MSP-EXP430G2 MSP430 LaunchPad

SparkFun Fingerprint Scanner - TTL (GT-511C3)

SG90 Micro-servo motor

Jumper wires (generic)

CP2102 USB 2.0 to TTL UART Serial convertor Module

Software apps and online services

Texas Instruments Energia

Story

Introduction

For most people living in hostels or dormitories, locking the front door when going out for a few minutes can be a hassle, especially if you keep forgetting your keys in the room every time you leave. Never again will this be a problem, when the only key that you'll ever need will be at your fingertips.

Abstract

The design of the system is fairly simple.

• Person places their finger on the fingerprint sensor

• If the fingerprint happens to match one of the fingerprints stored in the scanner, a servo motor turns opening the door lock

.• Hey presto, the door unlocks

Important

The library used for the Fingerprint scanner is the same one that is used for the Arduino. As a result, the library, in its current state will not work with the MSP430. To rectify this, do the following:

•Get the main code for the fingerprint sensor from the following link: https://github.com/sparkfun/Fingerprint_Scanner-TTL

•Go to the main Energia file where the.exe is stored and then find the Software Serial folder inside the./hardware/msp430/libraries subdirectory.

•Copy the Software Serial folder to the msp430/libraries

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The video showing how it works

The working of the GT-511C3 fingerprint scanner with MSP430 is shown in the above video.

Code

FingerPrint Scanner Code

#include <SoftwareSerial.h>
#include <FPS_GT511C3.h>


FPS_GT511C3 fps(P2_5,P2_4 ); // (TX pin of fps<-->msp pin P2.5, RX pin of fps<-->msp pin P2.4)

int servo = 11; // Servo pin <--> Pin P2.6

int angle;
int pwm;

void setup()
{
  Serial.begin(9600); //set up Arduino's hardware serial UART
   pinMode(servo, OUTPUT);
 
   fps.Open();         //send serial command to initialize fps
   fps.SetLED(true);   //turn on LED so fps can see fingerprint
 
 }

void loop()
{
  
  if (fps.IsPressFinger())
   recogniseFingerprint();
 
  
    }


void recogniseFingerprint()
{    
    Serial.print(".......");
   if (fps.IsPressFinger())
    {  fps.CaptureFinger(false);
       int id = fps.Identify1_N();
    

    // GT-511C3 can hold 200 fingerprint templates. 
                
    if (id <200) //<- change id value depending model you are using
    {//if the fingerprint matches, provide the matching template ID
      Serial.print("Verified ID:");
      Serial.println(id);
      rotateServo();
    }
    else
        {//if unable to recognize
         Serial.println("Finger not found");}
     }
  else
  {
    Serial.println("Please press finger");
  }
  delay(50);
} 
  
void rotateServo()
{
  for (angle = 0; angle <= 180; angle += 10)  {
   servoPulse(servo, angle);  }
   while(fps.IsPressFinger());
   for (angle = 180; angle >= 0; angle -= 10)  {
   servoPulse(servo, angle);  }
   delay(1000);
 }



void servoPulse (int servo, int angle)
{
 pwm = (angle*11) + 500;      // Convert angle to microseconds
 digitalWrite(servo, HIGH);
 delayMicroseconds(pwm);
 digitalWrite(servo, LOW);
 delay(50);                   // Refresh cycle of servo
}