Arduino-Based-RFID-Access-System-C-C-Arduino

Performed DFMEA analysis on eight subsystems using AIAG methodology to identify and mitigate high-risk failure modes. Developed a state machine–driven microcontroller security system integrating RFID authentication, ultrasonic sensing, dual-servo control, and LCD/joystick interface for real-time monitoring and alerts.

//Project: Safe With A Built-In Security System //Author: Andrew Dikho, Aidan Konja, Luke Zora, Lauren Petterle //Date: 04/21/2025

//RFID logic adapted from MFRC522 library example "DumpInfo" by GithubCommunity //Modifications: Added access control with 2 keycards, servo activation, sound playback, and state machine management

#include <SPI.h> #include <MFRC522.h> #include <Servo.h> #include <LiquidCrystal.h>

#define SS_PIN 53 #define RST_PIN 11 #define TRIG_PIN 25 #define ECHO_PIN 23 #define pitches.h

const int G1 = 2, G2 = 3, G3 = 4, Y1 = 5, Y2 = 6, Y3 = 7, R1 = 8, R2 = 9, R3 = 10; const int buzz = A2; const int rs = 33, en = 32, d4 = 31, d5 = 43, d6 = 41, d7 = 39; const int joystickbutton = 49;

int distance = 36; // Assumes Max distance int state = 1; // Assumes initial state = 1 int lastState = -1; // Tracks previous state to avoid flickering on LCD bool servoposition = false; // Inside latchopen() and joystick() to avoid code running more than it should bool lastPressed = false; // Tracks joysticks state, Low or High and debounces button unsigned long lastBlinkTime = 0; // Stores last time the LED's changed state bool ledsOn = false; //Stores LED state on or off for FlashingLED() bool initialized = false; //Stores a variable in state 3 to keep from flickering on LCD and unneccesary movements on Servo

MFRC522 mfrc522(SS_PIN, RST_PIN); Servo myServo; Servo myServo2; LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

void setup() { Serial.begin(9600); lcd.begin(16, 2);

pinMode(TRIG_PIN, OUTPUT); pinMode(ECHO_PIN, INPUT); pinMode(buzz, OUTPUT); pinMode(joystickbutton, INPUT_PULLUP);

for (int i = 2; i <= 10; i++) pinMode(i, OUTPUT); // Sets all LED's to OUTPUTS

SPI.begin(); // Initializes RFID mfrc522.PCD_Init(); // RFID myServo.attach(12); // Distance Srvo myServo.write(0); // Set To Default Distance myServo2.attach(13); // Latch Servo myServo2.write(0); // Sets Default

Serial.println("System Initialized"); //Stores that initial conditions are set on Serial Monitor }

void loop() { distance = sensprox();

switch (state) { //Enables State Machine case 1: state1(); break; // Runs state1() function once and break; prevents from running another case case 2: state2(); break; // Runs state2() function once and break; prevents from running another case case 3: state3(); break; // Runs state3() function once and break; prevents from running another case }

joystick();

if (state == 1) { //Runs along with state1() function lcd.clear(); lcd.setCursor(0, 0); if (distance == 36) { // If distance is equal or more than 36 inches, no distnace is shown lcd.print("NO MOTION"); lcd.setCursor(0, 1); lcd.print("Distance: -- in "); } else { lcd.print("MOTION DETECTED"); // Once distance is less than 36 inches lcd updates to show accurate distance in inches lcd.setCursor(0, 1); lcd.print("Distance: "); lcd.print(distance); lcd.print(" in "); } }

if (state == 2) { lcd.clear(); lcd.setCursor(0, 0); lcd.print("WARNING"); lcd.setCursor(0, 1); lcd.print("SCAN TO DISARM"); lastState = state; // holds most accurate state reading } }

void state1() { initialized = false; ledprox(); buzzprox(); gaugeprox(); scan();

if (state != lastState) { lcd.clear(); lcd.setCursor(0, 0); lcd.print("NO MOTION"); lastState = state; } }

void state2() { flashingLED(); buzzmaxfreq(); gaugeproxmax(); sensproxoff(); latchopen(); }

void state3() { if (!initialized) { LEDoff(); buzzeroff(); gaugeproxdefault();

lcd.clear();
lcd.setCursor(0, 0);
lcd.print("ACCESS GRANTED");
lcd.setCursor(0, 1);
lcd.print("Welcome!");
delay(2000);

lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Press Joystick");
lcd.setCursor(0, 1);
lcd.print("To Reset Alarm");

initialized = true;

} }

void scan() { static int closeCount = 0; //static holds number across loop iterations/ counts how many times the object is close <= 11 static unsigned long lastScanTime = 0; // Holds last time scan checked the distance const unsigned long scanInterval = 150; // Minimum time between scans 150ms

if (millis() - lastScanTime < scanInterval) return; // Scans every 150ms whether distance is <= 11 or not lastScanTime = millis(); // Holds last scan time

if (distance <= 11) { closeCount++; if (closeCount >= 3) { Serial.println("✅ State changed to 2"); state = 2; closeCount = 0; } } else { closeCount = 0; } }

int sensprox() { digitalWrite(TRIG_PIN, LOW); delayMicroseconds(2); digitalWrite(TRIG_PIN, HIGH); delayMicroseconds(10); digitalWrite(TRIG_PIN, LOW);

long duration = pulseIn(ECHO_PIN, HIGH, 30000); int newDist = (int)(duration * 0.0135 / 2); // Converts distance to inches if (duration == 0 || newDist < 1 || newDist > 36) return 36; // Duration - 0 (Nothing Detected) newDist < 0, too close, greater than 36, out of range return newDist; // Will Return 36 if any of those statements are true, if not returns correct distance (newDist) } // Function adapted from MFRC522 "DumpInfo" example // Modified to implement custom control and integrate with state machine void latchopen() { if (!mfrc522.PICC_IsNewCardPresent() || !mfrc522.PICC_ReadCardSerial()) return;

String readUID = ""; for (byte i = 0; i < mfrc522.uid.size; i++) { if (mfrc522.uid.uidByte[i] < 0x10) readUID += "0"; readUID += String(mfrc522.uid.uidByte[i], HEX); } readUID.toUpperCase();

Serial.print("Scanned UID: "); //Displays the correct keykard that is scanned Serial.println(readUID);

if (readUID == "D7E42403" || readUID == "C37A762D") { // The 2 Keycards included in our Kit Serial.println("✅ Access Granted"); myServo2.write(180); //Opens Latch delay(750);
play1upsound(); //Plays sound to signal access granted servoposition = true; // Holds state that the latch was open state = 3; // State 3 is activated } else { Serial.println("❌ Access Denied"); }

mfrc522.PICC_HaltA(); mfrc522.PCD_StopCrypto1(); }

void joystick() { static unsigned long lastDebounceTime = 0; const unsigned long debounceDelay = 50;

bool currentlyPressed = digitalRead(joystickbutton) == LOW; //Comparing the button reading to LOW, Low == Button Press, High == Rest

if (currentlyPressed && !lastPressed && millis() - lastDebounceTime > debounceDelay) { // ONLY runs when currentlyPressed is true lastDebounceTime = millis(); //Records last time button was pressed //!last Pressed will always return true // lastdebounceTime will always be bigger than debouncedelay(50) if (state == 3) { Serial.println("🕹 Joystick Pressed → Resetting system"); myServo2.write(0); servoposition = false; sensproxon(); playMarioMusic(); lcd.clear(); lcd.setCursor(0,0); lcd.print(" Resetting"); lcd.setCursor(0,1); lcd.print(" System..."); delay(5000); state = 1; lastState = -1; initialized = false;

  digitalWrite(buzz, HIGH);
  delay(100);
  digitalWrite(buzz, LOW);
}

}

lastPressed = currentlyPressed; //Resets back to current button state }

void sensproxon() { pinMode(TRIG_PIN, OUTPUT); //Turns Sensor On pinMode(ECHO_PIN, INPUT); }

void sensproxoff() { pinMode(TRIG_PIN, INPUT); //Disables this pin , stops from sending signals to read a distance from pinMode(ECHO_PIN, INPUT); distance = 36; }

void ledprox() { // Maps All LED's to a threshold to give a smooth flow with proximity analogWrite(G2, map(constrain(distance, 32, 36), 36, 32, 0, 255)); analogWrite(G1, map(constrain(distance, 28, 32), 32, 28, 0, 255)); analogWrite(G3, map(constrain(distance, 24, 28), 28, 24, 0, 255)); analogWrite(Y1, map(constrain(distance, 20, 24), 24, 20, 0, 255)); analogWrite(Y2, map(constrain(distance, 16, 20), 20, 16, 0, 255)); analogWrite(Y3, map(constrain(distance, 12, 16), 16, 12, 0, 255)); analogWrite(R1, map(constrain(distance, 8, 12), 12, 8, 0, 255)); analogWrite(R2, map(constrain(distance, 4, 8), 8, 4, 0, 255)); analogWrite(R3, map(constrain(distance, 1, 4), 4, 1, 0, 255)); }

void buzzprox() { //Maps Buzzer Based on Prox. if (distance >= 36) noTone(buzz); else tone(buzz, map(distance, 36, 1, 100, 2000)); }

void gaugeprox() { // Maps Gauge Servo based on Prox. int angle = map(distance, 36, 1, 180, 0); angle = constrain(angle, 0, 180); myServo.write(angle); Serial.print("Distance: "); Serial.print(distance); Serial.print(" : Servo angle: "); Serial.println(angle); }

void flashingLED() { //Blinks the LED's every 500ms if (millis() - lastBlinkTime >= 500) { ledsOn = !ledsOn; for (int i = 2; i <= 10; i++) digitalWrite(i, ledsOn ? HIGH : LOW); // If ledson == false turn on LED's, else turn them off lastBlinkTime = millis(); } }

void buzzmaxfreq() { //Alarm noise in State 2 tone(buzz, 2000); }

void gaugeproxmax() { // Signaling "Danger" on the Gauge on Front of Box myServo.write(0); }

void LEDoff() { for (int i = 2; i <= 10; i++) digitalWrite(i, LOW); //Turns LED's OFF }

void buzzeroff() { // Turns Buzzer OFF noTone(buzz); digitalWrite(buzz, LOW); }

void gaugeproxdefault() { myServo.write(180); }

void playMarioMusic() { // Mario Theme Melody Code by TECHARENA, modified for Arduino Mega project // https://www.hackster.io/techarea98/super-mario-theme-song-with-piezo-buzzer-and-arduino-2cc461

#define NOTE_E6 1319 #define NOTE_G6 1568 #define NOTE_A6 1760 #define NOTE_AS6 1865 #define NOTE_B6 1976 #define NOTE_C7 2093 #define NOTE_D7 2349 #define NOTE_E7 2637 #define NOTE_F7 2794 #define NOTE_G7 3136 #define NOTE_A7 3520

int melodyPin = buzz; pinMode(melodyPin, OUTPUT);

int melody[] = { NOTE_E7, NOTE_E7, 0, NOTE_E7, 0, NOTE_C7, NOTE_E7, 0, NOTE_G7, 0, 0, 0, NOTE_G6, 0, 0, 0, NOTE_C7, 0, 0, NOTE_G6, 0, 0, NOTE_E6, 0, 0, NOTE_A6, 0, NOTE_B6, 0, NOTE_AS6, NOTE_A6, 0, NOTE_G6, NOTE_E7, NOTE_G7, NOTE_A7, 0, NOTE_F7, NOTE_G7, 0, NOTE_E7, 0, NOTE_C7, NOTE_D7, NOTE_B6, 0, 0, NOTE_C7, 0, 0, NOTE_G6, 0, 0, NOTE_E6, 0, 0, NOTE_A6, 0, NOTE_B6, 0, NOTE_AS6, NOTE_A6, 0, NOTE_G6, NOTE_E7, NOTE_G7, NOTE_A7, 0, NOTE_F7, NOTE_G7, 0, NOTE_E7, 0, NOTE_C7, NOTE_D7, NOTE_B6, 0, 0 };

int tempo[] = { 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 9, 9, 9, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 9, 9, 9, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12 };

int size = sizeof(melody) / sizeof(melody[0]);

for (int thisNote = 0; thisNote < size; thisNote++) { int noteDuration = 1000 / tempo[thisNote]; int freq = melody[thisNote];

if (freq == 0) {
  delay(noteDuration); // Rest
} else {
  long delayValue = 1000000 / freq / 2;
  long numCycles = (long)freq * noteDuration / 1000;

  for (long i = 0; i < numCycles; i++) {
    digitalWrite(melodyPin, HIGH);
    delayMicroseconds(delayValue);
    digitalWrite(melodyPin, LOW);
    delayMicroseconds(delayValue);
  }
}


delay(noteDuration * 1.30);

} }

void play1upsound() { // Mario 1-Up Sound by Benjamin T. Perry, modified for Arduino Mega Project // https://bikeshedeffect.weebly.com/arduino-piezo-sounds.html

// Play 1-up sound tone(buzz,NOTE_E6,125); delay(130); tone(buzz,NOTE_G6,125); delay(130); tone(buzz,NOTE_E7,125); delay(130); tone(buzz,NOTE_C7,125); delay(130); tone(buzz,NOTE_D7,125); delay(130); tone(buzz,NOTE_G7,125); delay(125); noTone(buzz); }