Arduino code for fingerprint and buzzer alarm

Projects General Guidance
11

To modify the code to add a buzzer alarm sound when an unauthorized finger is detected, you can add an additional case in the getFingerprintID() function for FINGERPRINT_NOTFOUND, which will trigger the buzzer to sound:

#include <Adafruit_Fingerprint.h>
//For Arduino UNO use pin #D2 from sensor (GREEN wire)
// pin #D3 is OUT from arduino (WHITE wire)
//For Arduino MEGA use pin #D10 from sensor (GREEN wire)
// pin #D11 is OUT from arduino (WHITE wire)
#include <SoftwareSerial.h>
SoftwareSerial mySerial(10, 11);
Adafruit_Fingerprint finger = Adafruit_Fingerprint(&mySerial);

//BUZZER pin
const int buzzer = 8;

void setup() {
  Serial.begin(9600);
  while (!Serial); // For Yun/Leo/Micro/Zero/...
  delay(100);
  Serial.println("\n\n Finger detect test");

  // set the data rate for the sensor serial port
  finger.begin(57600);
  if (finger.verifyPassword()) {
    Serial.println("Found fingerprint sensor!");
  } else {
    Serial.println("Did not find fingerprint sensor :(");
    while (1) { delay(1); }
  }

  //BUZZER
  pinMode(buzzer, OUTPUT);

  finger.getTemplateCount();
  Serial.print("Sensor contains "); Serial.print(finger.templateCount); Serial.println(" templates");
  Serial.println("Waiting for valid finger...");
}

void loop() // run over and over again
{
  getFingerprintIDez();
  delay(50); //don't ned to run this at full speed.
}

uint8_t getFingerprintID() {
  uint8_t p = finger.getImage();
  switch (p) {
    case FINGERPRINT_OK:
      Serial.println("Image taken");
      break;
    case FINGERPRINT_NOFINGER:
      Serial.println("No finger detected");
      digitalWrite(buzzer, HIGH); //UNINDENTIFIED = LOCK
      delay(3000);
      digitalWrite(buzzer, LOW);
      break;
    case FINGERPRINT_PACKETRECIEVEERR:
      Serial.println("Communication error");
      break;
    case FINGERPRINT_IMAGEFAIL:
      Serial.println("Imaging error");
      break;
    default:
      Serial.println("Unknown error");
      break;
  }

  if (p != FINGERPRINT_OK) {
    return p;
  }

  p = finger.image2Tz();
  switch (p) {
    case FINGERPRINT_OK:
      Serial.println("Image converted");
      break;
    case FINGERPRINT_IMAGEMESS:
      Serial.println("Image too messy");
      break;
    case FINGERPRINT_PACKETRECIEVEERR:
      Serial.println("Communication error");
      break;
    case FINGERPRINT_FEATUREFAIL:
      Serial.println("Could not find fingerprint features");
      break;
    case FINGERPRINT_INVALIDIMAGE:
      Serial.println("Could not find fingerprint features");
      break;
    default:
      Serial.println("Unknown error");
      break;
  }

  if (p != FINGERPRINT_OK) {
    return p;
  }

  p = finger.fingerFastSearch();
  
  if (p == FINGERPRINT_OK) {
    Serial.println("Found a print match!");
    // Unlock the door
    digitalWrite(buzzer, LOW); // turn off buzzer
  } else {
    Serial.println("Did not find a match");
    // Sound the alarm
    digitalWrite(buzzer, HIGH); // turn on buzzer
  }
  
  // found a match!
  Serial.print("Found ID #"); Serial.print(finger.fingerID); 
  Serial.print(" with confidence of "); Serial.println(finger.confidence);

  
  // Return the finger ID
  return finger.fingerID;
}

// 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) {
    Serial.println("Found a print match!");
    // Unlock the door
    digitalWrite(buzzer, LOW); // turn off buzzer
   } else {
     Serial.println("Did not find a match");
     // Sound the alarm
     digitalWrite(buzzer, HIGH); // turn on buzzer
   }
  
   // found a match!
   Serial.print("Found ID #"); Serial.print(finger.fingerID); 
   Serial.print(" with confidence of "); Serial.println(finger.confidence);

  
   // Return the finger ID
   return finger.fingerID; 
}

I'm not sure if this code will work as I don't have the contents of the "SoftwareSerial.h". But you don't have to post them either. Also, unfortunately I don't know how long the buzzer is then. But you can usually set that higher with the "Delay", which is set to 50. I hope it works now

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