Introduction

In this article, I will explain how to create a Fingerprint Lock using Arduino Mega 2560. It will be used to identify the same user in the same way that a fingerprint scanner works.
Parts
  • Fingerprint sensor
  • Arduino Mega 2560
  • Servo motor
  • Jumper wires
Fingerprint Sensor
Figure 1: Fingerprint Sensor
  • It is an electronic device and captures digital images.
  • The captured image is called a live scan.
  • It simply identifies the fingerprint and gives the result.
  • It can easily match the fingerprint.
Connection:
Step 1: Connection From Servo Motor To Arduino Mega 2560,
  • The servo first pin can be connected to the Gnd.
  • The second pin can be connected to the VCC.
  • The third pin can be connected to the digital pin 06 of the Arduino Mega 2560.
Step 2: Connection From Fingerprint Sensor To Arduino Mega 2560,
  • The Gnd pin of the fingerprint sensor to the Gnd of the Arduino Mega 2560
  • The Vcc pin of the fingerprint sensor to the 5v of the Arduino Mega 2560
  • The Rx pin can be connected to the A4 of the Arduino Mega 2560.
  • The Tx pin can be connected to the A5 of the Arduino Mega 2560.
Programming
  1. #include<Fingerprint.h>
  2. #include<SoftwareSerial.h>
  3. #include<Streaming.h>
  4. #include<Servo.h>
  6. #define __Debug 1
  8. const int pinServo = 6;
  9. const int angleServo = 60;
  11. #if __Debug
  12. #define DBG(X) Serial.println(X)
  13. #else
  14. #define DBG(X)
  15. #endif
  17. SoftwareSerial mySerial(A5, A4);
  18. Fingerprint finger = Fingerprint( & mySerial);
  19. Servo myservo;
  21. void open_close_door()
  22. {
  23. myservo.attach(pinServo);
  24. for (int i = 20; i < angleServo; i++)
  25. {
  26. myservo.write(i);
  27. delay(5);
  28. }
  29. delay(2000);
  30. for (int i = (angleServo - 1); i >= 20; i--)
  31. {
  32. myservo.write(i);
  33. delay(5);
  34. }
  35. myservo.detach();
  36. }
  38. void setup()
  39. {
  40. Serial.begin(38400);
  41. finger.begin(19200);
  42. delay(500);
  43. DBG("setup ok!");
  44. }
  46. void loop()
  47. {
  48. if (getFingerprintIDez() >= 0)
  49. {
  50. open_close_door();
  51. DBG("get right finger, open door now!!");
  52. delay(2000);
  53. }
  54. delay(50);
  55. }
  57. int getFingerprintIDez()
  58. {
  59. if (!finger.verifyPassword())
  60. {
  61. DBG("Did not find fingerprint sensor :(");
  62. return -1;
  63. }
  64. uint8_t p = finger.getImage();
  65. if (p != FINGERPRINT_OK)
  66. {
  67. return -1;
  68. }
  69. p = finger.image2Tz();
  70. if (p != FINGERPRINT_OK)
  71. {
  72. return -1;
  73. }
  74. p = finger.fingerFastSearch();
  75. if (p != FINGERPRINT_OK)
  76. {
  77. return -1;
  78. }
  79. #if __Debug
  80. Serial.print("Found ID #");
  81. Serial.print(finger.fingerID);
  82. Serial.print(" with confidence of ");
  83. DBG(finger.confidence);
  84. #endif
  86. return finger.fingerID;
  87. }
Explanation:
  • When the fingerprint is the same, the sensor identifies it and prints the message as matched.
  • The servo motor also gets rotate to the 60-degree direction.
  • When fingerprints do not match, a message is sent as "Not Matched."
Output:
Figure 2: Output.
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