Program and Test

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Download Fingerprint and Keypad Libraries

Enroll Fingers

Load code

  • Load the Biometric Box sketch at the bottom of this page.
  • Edit the "secretCode" string to define your passcode.
  • Compile and upload the sketch.

Test the Latch Operation

  • Power on the box - the led on the power switch should flash a few times, then start to 'breathe'.
  • Enter your passcode - the fingerprint sensor should turn on and glow red.
  • Place your finger on the sensor and you should hear the solenoid click.

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Copy Code 
/*************************************************** 
  Biometric Box Sketch for the optical Fingerprint sensor
  This sketch implements a two-level security scheme requiring the
  user to enter a passcode via the keypad before scanning a fingerprint
  for access.

  Adafruit invests time and resources providing this open source code, 
  please support Adafruit and open-source hardware by purchasing 
  products from Adafruit!

  Written by Bill Earl for Adafruit Industries.  
  BSD license, all text above must be included in any redistribution
 ****************************************************/
#include <Keypad.h>
#include <Adafruit_Fingerprint.h>
#include <SoftwareSerial.h>

// Define the states for the lock state machine
#define LOCKED 2
#define PASSWORD_OK 1
#define UNLOCKED 0

// State Variables:   Initialize to the locked state
int LockState = LOCKED;
long StartTime = 0;
int position = 0;

// Define your password key sequence here
char* secretCode = "1423";

// Keypad key matrix:
const byte rows = 4; 
const byte cols = 3; 
char keys[rows][cols] = 
{
   {'1','2','3'},
   {'4','5','6'},
   {'7','8','9'},
   {'*','0','#'}
};

// Keypad pin definitions
byte rowPins[rows] = {2, 3, 4, 5}; 
byte colPins[cols] = {6, 7, 8};  

// Instantiate the keypad
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, rows, cols);

// More pin definitions:
int LedPin = 10;
int SolenoidPin = 11;

// Define a Fingerprint sensor on pins 12 & 13
int getFingerprintIDez();
SoftwareSerial mySerial(13, 12);
Adafruit_Fingerprint finger = Adafruit_Fingerprint(&mySerial);


void setup()                    
{
   pinMode(LedPin, OUTPUT);
   pinMode(SolenoidPin, OUTPUT);
   
   // Flash hello
   for (int i = 0; i < 3; i++)
   {
     digitalWrite(LedPin, HIGH);
     delay(100);
     digitalWrite(LedPin, LOW);
     delay(100);
   }
   
   // Initialize state and communicatins
   setLockState(LOCKED); 
   Serial.begin(9600); 
   finger.begin(57600);

   // Connect to the sensor
   if (finger.verifyPassword()) 
   {
      Serial.println("Found fingerprint sensor!");
   } 
   else 
   {
      Serial.println("Did not find fingerprint sensor :(");
      while (1);
   }
}


void loop()                    
{
   // Run the state machine:
   
   // Locked State - Monitor keypad for valid Password code entry
   if (LockState == LOCKED)
   {
      char key = keypad.getKey();

      if (key == '*' || key == '#')
      {
         position = 0;
         setLockState(LOCKED);
      }
      if (key != 0)
      {
         if (key == secretCode[position])  // Valid key in Password sequence
         {
            Serial.print("Matched ");   
            Serial.print(key);   
            Serial.print("-at-");   
            Serial.println(position);   
            position ++;
         }
         else  // Invalid key - start all over again
         {
            Serial.println("Invalid Code!");   
            position = 0;
         }
      }

      // Let the LED 'breathe' while we wait
      analogWrite(LedPin, sin((millis() % 3142) / 1000.0) * 255);

      if (position == 4)  // Password successfully entered - advance state
      {
         setLockState(PASSWORD_OK);
         position = 0;
      }
      delay(100);
   }

   // PASSWORD_OK state - Now wait for a valid fingerprint reading
   else if (LockState == PASSWORD_OK)
   { 
      if (getFingerprintIDez() != -1)
      {
         setLockState(UNLOCKED); // Valid fingerprint - advance state to UNLOCKED
      }
      if (millis () - StartTime > 5000) 
      {
         setLockState (LOCKED); // Time-out - go back to the LOCKED state
      }
   }

   // UNLOCKED state - hold the solenoid open for a limited time
   else if (LockState == UNLOCKED)
   { 
      for (int i = 0; i < 30; i++)
      {
         // Flash the led to indicate the lock is open
         digitalWrite(LedPin, LOW);
         delay(50);
         digitalWrite(LedPin, HIGH);
         delay(50);
      }
      setLockState (LOCKED);  // Time-out - go back to the locked state.
   }
}



// returns -1 if failed, otherwise returns ID #
int getFingerprintIDez() 
{
   uint8_t 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!
   Serial.print("Found ID #"); Serial.print(finger.fingerID); 
   Serial.print(" with confidence of "); Serial.println(finger.confidence);
   return finger.fingerID; 
}


// Set the state and the time of the state change
void setLockState(int state)
{
   LockState = state;
   StartTime = millis ();
   if (state == LOCKED)
   {
      Serial.println("Locked!");
      digitalWrite(LedPin, HIGH);
      digitalWrite(SolenoidPin, LOW);  
   }

   else if (state == PASSWORD_OK)
   {
      Serial.println("PASSWORD_OK!");
      digitalWrite(LedPin, LOW);  
   }    
   else if (state == UNLOCKED)
   {
      Serial.println("Unlocked!");
      digitalWrite(LedPin, LOW);
      digitalWrite(SolenoidPin, HIGH);      
   }
}
 Pre-Assembly Final Assembly 

This guide was first published on Dec 29, 2012. It was last updated on Dec 29, 2012.

This page (Program and Test) was last updated on Aug 14, 2012.

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