Circuit Documentation
Summary
This circuit is a SmartSafe Vault system that utilizes an Arduino UNO microcontroller to control various components including a Servo Motor, an LCD display, an IR Receiver, a Buzzer, and an RFID reader. The system is designed to unlock and lock a safe based on RFID card scans and PIN inputs via an IR remote.
Component List
Servo Motor (SG90)
- Description: A small servo motor used to lock and unlock the safe.
- Pins: Pin3, 5V, GND
MKE-M07 LCD1602 I2C
- Description: An I2C LCD display used to show messages and status.
- Pins: GND, 5V, SDA, SCL
IR Receiver
- Description: An infrared receiver used to receive signals from an IR remote.
- Pins: DATA, VCC, GND
Buzzer
- Description: A buzzer used to provide audio feedback.
- Pins: PIN, GND
Arduino UNO
- Description: The main microcontroller used to control all components.
- Pins: UNUSED, IOREF, Reset, 3.3V, 5V, GND, Vin, A0, A1, A2, A3, A4, A5, SCL, SDA, AREF, D13, D12, D11, D10, D9, D8, D7, D6, D5, D4, D3, D2, D1, D0
RFID-RC522
- Description: An RFID reader used to scan RFID cards.
- Pins: VCC (3.3V), RST, GND, IRQ, MISO, MOSI, SCK, SDA
Wiring Details
Servo Motor (SG90)
- Pin3 connected to D3 on Arduino UNO
- 5V connected to 5V on Arduino UNO
- GND connected to GND on Arduino UNO
MKE-M07 LCD1602 I2C
- GND connected to GND on Arduino UNO
- 5V connected to 5V on Arduino UNO
- SDA connected to A4 on Arduino UNO
- SCL connected to A5 on Arduino UNO
IR Receiver
- DATA connected to D7 on Arduino UNO
- VCC connected to 5V on Arduino UNO
- GND connected to GND on Arduino UNO
Buzzer
- PIN connected to D5 on Arduino UNO
- GND connected to GND on Arduino UNO
RFID-RC522
- VCC (3.3V) connected to 3.3V on Arduino UNO
- RST connected to D9 on Arduino UNO
- GND connected to GND on Arduino UNO
- MISO connected to D12 on Arduino UNO
- MOSI connected to D11 on Arduino UNO
- SCK connected to D13 on Arduino UNO
- SDA connected to D10 on Arduino UNO
Documented Code
#include <Servo.h>
#include <SPI.h>
#include <MFRC522.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <IRremote.h>
#define RST_PIN 9
#define SS_PIN 10
#define RECV_PIN 7
Servo lockServo;
MFRC522 rfid(SS_PIN, RST_PIN);
LiquidCrystal_I2C lcd(0x27, 16, 2);
IRrecv irrecv(RECV_PIN);
decode_results results;
const String correctUID = "21 C9 F7 A";
const String defaultPIN = "2580";
String enteredPIN = "";
bool isUnlocked = false;
int buzzer = 4;
int failedAttempts = 0;
const int maxAttempts = 5;
void setup() {
pinMode(buzzer, OUTPUT);
Serial.begin(9600);
SPI.begin();
rfid.PCD_Init();
irrecv.enableIRIn();
lockServo.attach(3);
lockServo.write(0);
lcd.init();
lcd.backlight();
digitalWrite(buzzer, HIGH);
delay(50);
digitalWrite(buzzer, LOW);
printCentered("** GROUP 5 **", 0);
printCentered("SmartSafe Vault", 1);
delay(3000);
lcd.clear();
lockSafe();
digitalWrite(buzzer, HIGH);
delay(200);
digitalWrite(buzzer, LOW);
}
void loop() {
handleIRInput();
if (!rfid.PICC_IsNewCardPresent() || !rfid.PICC_ReadCardSerial()) {
return;
}
String scannedUID = "";
for (byte i = 0; i < rfid.uid.size; i++) {
String hexByte = String(rfid.uid.uidByte[i], HEX);
hexByte.toUpperCase();
scannedUID += hexByte;
if (i < rfid.uid.size - 1) scannedUID += " ";
}
lcd.clear();
printCentered("Scanned card", 0);
printCentered(scannedUID, 1);
delay(1000);
if (scannedUID == correctUID) {
if (!isUnlocked) {
unlockSafe();
} else {
lockSafe();
}
failedAttempts = 0;
} else {
if (!isUnlocked) {
failedAttempts++;
}
errCard();
if (failedAttempts >= maxAttempts) {
lockout();
failedAttempts = 0;
} else {
displayAttemptsLeft();
}
if (isUnlocked) {
lockSafe();
}
}
rfid.PICC_HaltA();
}
void handleIRInput() {
if (irrecv.decode(&results)) {
String key = decodeKey(results.value);
irrecv.resume();
if (key != "") {
if (isUnlocked) {
lockSafe();
enteredPIN = "";
return;
}
enteredPIN += key;
lcd.clear();
digitalWrite(buzzer, HIGH);
delay(10);
digitalWrite(buzzer, LOW);
printCentered("Entered PIN", 0);
printCentered("> " + maskPIN(enteredPIN) + " <", 1);
if (enteredPIN.length() == 4) {
delay(500);
if (enteredPIN == defaultPIN) {
unlockSafe();
enteredPIN = "";
failedAttempts = 0;
} else {
lcd.clear();
printCentered("Incorrect PIN", 0);
printCentered("Try again", 1);
enteredPIN = "";
failedAttempts++;
delay(2000);
lockSafe();
if (isUnlocked) {
lockSafe();
}
if (failedAttempts >= maxAttempts) {
lockout();
failedAttempts = 0;
}
}
}
}
}
}
String decodeKey(unsigned long value) {
switch (value) {
case 0xFF4AB5: return "0";
case 0xFF6897: return "1";
case 0xFF9867: return "2";
case 0xFFB04F: return "3";
case 0xFF30CF: return "4";
case 0xFF18E7: return "5";
case 0xFF7A85: return "6";
case 0xFF10EF: return "7";
case 0xFF38C7: return "8";
case 0xFF5AA5: return "9";
// case 0xFF02FD: return "0000";
default: return "";
}
}
String maskPIN(String pin) {
String masked = "";
for (int i = 0; i < pin.length(); i++) {
masked += "*";
}
return masked;
}
void unlockSafe() {
lockServo.write(90);
isUnlocked = true;
lcd.clear();
printCentered("Safe unlocked", 0);
printCentered("successfully!", 1);
onBeep();
delay(2000);
printCentered("Scan ID or press", 0);
printCentered("any key to lock.", 1);
}
void lockSafe() {
lockServo.write(0);
isUnlocked = false;
lcd.clear();
printCentered("Safe locked", 0);
printCentered("successfully!", 1);
onBeep();
delay(2000);
printCentered("Safe is locked", 0);
displayAttemptsLeft();
offBeep();
}
void displayAttemptsLeft() {
printCentered("Attempts: " + String(maxAttempts - failedAttempts), 1);
}
void errCard() {
lcd.clear();
if (isUnlocked) {
printCentered("Safe locked", 0);
printCentered("successfully!", 1);
} else {
printCentered("Access denied!", 0);
printCentered("Invalid card",