Creating a fingerprint door lock with Arduino and a solenoid involves merging biometric technology with a physical locking mechanism. It utilizes a fingerprint sensor module to scan and store fingerprints, while an Arduino board processes this data and commands a solenoid to control the lock mechanism. When a recognized fingerprint is detected, the Arduino triggers the solenoid to unlock the door. Wiring the components as per a schematic and programming the Arduino to manage fingerprint authentication and solenoid control are essential steps in this project. By integrating hardware, biometrics, and programming, this project provides a practical example of using Arduino for security applications, offering a customizable and efficient solution for door access control.

Code :-

// By Arduino Techy

                                   //

#include <Adafruit_Fingerprint.h>

SoftwareSerial mySerial(2, 3);

Adafruit_Fingerprint finger = Adafruit_Fingerprint(&mySerial);

#define RELAY_PIN       4

#define ACCESS_DELAY    3000 // Keep lock unlocked for 3 seconds 

void setup()

{

  // set the data rate for the sensor serial port

  finger.begin(57600);

  delay(5);

  if (finger.verifyPassword()) 

  {

  } 

  else 

  {

    while (1) { delay(1); }

  }

  pinMode(RELAY_PIN, OUTPUT);

  digitalWrite(RELAY_PIN, HIGH);  

}

void loop()

{

  if ( getFingerPrint() != -1)

  {

    digitalWrite(RELAY_PIN, LOW);

    delay(ACCESS_DELAY);

    digitalWrite(RELAY_PIN, HIGH);   

  }  

  delay(50);            //Add some delay before next scan.

}

// returns -1 if failed, otherwise returns ID #

int getFingerPrint() 

{

  int p = finger.getImage();

  if (p != FINGERPRINT_OK)  return -1;

  p = finger.image2Tz();

  if (p != FINGERPRINT_OK)  return -1;

  p = finger.fingerFastSearch();

  if (p != FINGERPRINT_OK)  return -1;

  // found a match!

  return finger.fingerID;

}

Components :-