Circuit Documentation

Summary

The circuit in question is designed to control access through a 12V Solenoid Lock, which is managed by an Arduino UNO microcontroller. The system uses a Fingerprint Scanner and a Voice Recognition Module as authentication methods. Upon successful authentication, the lock can be opened for a predetermined duration. The circuit also includes visual indicators (LEDs) and an audible indicator (Buzzer) to provide status feedback.

Component List

Arduino UNO

• Microcontroller board based on the ATmega328P.
• It has 14 digital input/output pins, 6 analog inputs, a 16 MHz quartz crystal, a USB connection, a power jack, an ICSP header, and a reset button.

Fingerprint Scanner

• A biometric sensor that captures fingerprints for authentication purposes.
• It typically operates at 3.3V and communicates via serial TX/RX lines.

Voice Recognition Module

• A module capable of recognizing pre-programmed voice commands.
• It requires a power supply and communicates with the microcontroller through serial lines.

KF-301 Relay

• An electromechanical switch used to control the high-power circuit of the solenoid lock.
• It has a signal input, power supply, and ground connections, along with Normally Closed (NC), Common (C), and Normally Open (NO) contacts.

12V Solenoid Lock

• An electrically-controlled lock that operates at 12V.
• It has two terminals for power supply connections.

Buzzer

• An audio signaling device that emits a tone when powered.
• It has positive and negative terminals.

LED: Two Pin (red)

• A red light-emitting diode that indicates power or status.
• It has an anode and cathode for connection to the power supply and ground, respectively.

LED: Two Pin (green)

• A green light-emitting diode used for status indication.
• Similar to the red LED, it has an anode and cathode.

12V Power Supply

• Provides the necessary power for the 12V components in the circuit, such as the solenoid lock.

Resistor (200 Ohms)

• A passive two-terminal electrical component that implements electrical resistance as a circuit element.
• Used for current limiting or voltage dropping.

Wiring Details

Arduino UNO

• 3.3V to Fingerprint Scanner VCC
• 5V to Voice Recognition Module VCC and KF-301 Relay power
• GND to Red LED cathode, Fingerprint Scanner GND, Green LED cathode, Voice Recognition Module GND, Buzzer NEGATIVE, and KF-301 Relay ground
• D9 to Resistor (connected to Red LED anode)
• D8 to Resistor (connected to Green LED anode)
• D7 to Buzzer POSITIVE
• D6 to KF-301 Relay signal
• D5 to Voice Recognition Module RDX
• D4 to Voice Recognition Module RTX
• D1 to Fingerprint Scanner RX
• D0 to Fingerprint Scanner TX

Fingerprint Scanner

• VCC to Arduino UNO 3.3V
• TX to Arduino UNO D0
• RX to Arduino UNO D1
• GND to Arduino UNO GND

Voice Recognition Module

• VCC to Arduino UNO 5V
• RDX to Arduino UNO D5
• RTX to Arduino UNO D4
• GND to Arduino UNO GND

KF-301 Relay

• signal to Arduino UNO D6
• power to Arduino UNO 5V
• ground to Arduino UNO GND
• C to 12V Solenoid Lock -
• NO to 12V Power Supply -

12V Solenoid Lock

• + to 12V Power Supply +
• - to KF-301 Relay C

Buzzer

• POSITIVE to Arduino UNO D7
• NEGATIVE to Arduino UNO GND

LED: Two Pin (red)

• anode through a 200 Ohm Resistor to Arduino UNO D9
• cathode to Arduino UNO GND

LED: Two Pin (green)

• anode through a 200 Ohm Resistor to Arduino UNO D8
• cathode to Arduino UNO GND

12V Power Supply

• + to 12V Solenoid Lock +
• - to KF-301 Relay NO

Resistor (200 Ohms)

• One resistor connected between Arduino UNO D9 and Red LED anode
• Another resistor connected between Arduino UNO D8 and Green LED anode

Documented Code

#include <Adafruit_Fingerprint.h>
#include <VoiceRecognitionV3.h>

// Define pins
#define VOICE_RX_PIN 4
#define VOICE_TX_PIN 5
#define RELAY_PIN 6      // Define relay control pin
#define BUZZER_PIN 7     // Define buzzer pin
#define RED_LED_PIN 8    // Define red LED pin
#define GREEN_LED_PIN 9  // Define green LED pin

// Hardware serial for fingerprint sensor (pins 0 and 1)
#define fingerprintSerial Serial

// Create instances
Adafruit_Fingerprint finger = Adafruit_Fingerprint(&fingerprintSerial);
VR myVR(VOICE_RX_PIN, VOICE_TX_PIN);  // Voice recognition instance

// Variables
bool fingerprintAuthenticated = false;
bool voiceAuthenticated = false;
bool accessGranted = false;
unsigned long unlockStartTime = 0;
const unsigned long unlockDuration = 10000; // 10 seconds unlock duration
const unsigned long lockoutDuration = 120000; // 120 seconds lockout duration
unsigned long lockoutStartTime = 0;
bool inLockout = false;

void setup() {
  // Initialize serial communication
  Serial.begin(9600);
  delay(100);

  // Initialize relay
  pinMode(RELAY_PIN, OUTPUT);
  digitalWrite(RELAY_PIN, HIGH);  // Ensure relay is off initially (active low)

  // Initialize buzzer
  pinMode(BUZZER_PIN, OUTPUT);
  digitalWrite(BUZZER_PIN, LOW);  // Buzzer off initially

  // Initialize LEDs
  pinMode(RED_LED_PIN, OUTPUT);
  pinMode(GREEN_LED_PIN, OUTPUT);
  digitalWrite(RED_LED_PIN, HIGH); // Red LED on as power indicator
  digitalWrite(GREEN_LED_PIN, LOW); // Green LED off initially

  // Initialize fingerprint sensor using hardware serial
  fingerprintSerial.begin(57600);
  finger.begin(57600);
  if (finger.verifyPassword()) {
    Serial.println("Found fingerprint sensor!");
  } else {
    Serial.println("Did not find fingerprint sensor :(");
    while (1) {
      delay(1);
    }
  }

  finger.getTemplateCount();
  Serial.print("Sensor contains ");
  Serial.print(finger.templateCount);
  Serial.println(" templates");

  // Initialize voice recognition module
  myVR.begin(9600); // Initialize SoftwareSerial for VR module

  // Load voice commands: 0-5
  for (uint8_t i = 0; i <= 5; i++) {
    if (myVR.load(i) >= 0) {  // Load each command
      Serial.print("Command '");
      Serial.print(i);
      Serial.println("' loaded.");
    } else {
      Serial.print("Failed to load command '");
      Serial.print(i);
      Serial.println("'.");
    }
  }

  Serial.println("Waiting for valid finger...");
}

void loop() {
  // Handle lockout state
  if (inLockout) {
    if (millis() - lockoutStartTime >= lockoutDuration) {
      inLockout = false;
      Serial.println("Lockout period ended.");
    } else {
      return; // Stay in lockout
    }
  }

  // Check fingerprint authentication
  if (!fingerprintAuthenticated && !inLockout) {
    int fingerID = getFingerprintIDez();
    if (fingerID >= 0 && fingerID <= 6) {
      fingerprintAuthenticated = true;
      digitalWrite(GREEN_LED_PIN, HIGH);  // Green LED on after fingerprint recognition
      Serial.println("Fingerprint authenticated. Please provide voice command.");
      delay(2000); // Hold green LED on for 2 seconds
      digitalWrite(GREEN_LED_PIN, LOW);   // Turn off green LED after 2 seconds
      unlockStartTime = millis(); // Record time of fingerprint authentication for voice input timing
    }
  }

  // Check voice authentication if fingerprint is authenticated
  if (fingerprintAuthenticated && !voiceAuthenticated && !inLockout) {
    uint8_t buf[64];
    int ret = myVR.recognize(buf, 50);
    if (ret > 0) {
      if (buf[1] >= 0 && buf[1] <= 5) { // Command IDs 0-5
        voiceAuthenticated = true;