RFID ACCESS CONTROL GATE - CIRCUIT DIAGRAM By Jan Niezgoda ============================================= COMPONENT LIST ============================================= □ Arduino Uno R3 □ RC522 RFID Reader Module □ SG90 Micro Servo Motor □ 16x2 LCD Display (HD44780 compatible) □ Green LED (5mm) □ Red LED (5mm) □ Active Buzzer (5V) □ 220Ω Resistor × 2 (for LEDs) □ Breadboard (830 tie-points) □ Jumper wires (Male-to-Male) □ RFID cards/key fobs (13.56MHz) □ USB cable for Arduino power □ Barrier arm material (lightweight plastic/cardboard) ============================================= PIN CONNECTIONS ============================================= ARDUINO UNO → RC522 RFID MODULE ──────────────────────────────── Pin 9 (Digital) → RST Pin 10 (Digital) → SDA/SS Pin 11 (MOSI) → MOSI Pin 12 (MISO) → MISO Pin 13 (SCK) → SCK 3.3V → VCC (IMPORTANT: 3.3V NOT 5V!) GND → GND ARDUINO UNO → SERVO MOTOR ──────────────────────────────── Pin 6 (Digital) → Signal (Orange/Yellow wire) 5V → Power (Red wire) GND → Ground (Brown/Black wire) ARDUINO UNO → LCD DISPLAY (Parallel Mode) ──────────────────────────────── Pin 7 (Digital) → RS (Register Select) Pin 8 (Digital) → Enable (E) Pin 2 (Digital) → D4 Pin 3 (Digital) → D5 Pin 4 (Digital) → D6 Pin 5 (Digital) → D7 5V → VCC GND → GND GND (or POT) → VSS 5V (or POT) → VDD POT (10kΩ) → V0 (Contrast - adjust for visibility) 5V → LED+ (Backlight anode) GND (or Resistor) → LED- (Backlight cathode) ARDUINO UNO → LEDs ──────────────────────────────── Pin A0 (Analog) → Green LED Anode (+) → 220Ω Resistor → GND Pin A1 (Analog) → Red LED Anode (+) → 220Ω Resistor → GND ARDUINO UNO → BUZZER ──────────────────────────────── Pin A2 (Analog) → Buzzer Positive (+) GND → Buzzer Negative (-) ============================================= POWER SUPPLY NOTES ============================================= - Arduino powered via USB (5V from computer) or external 9V adapter - RFID Module MUST use 3.3V (using 5V may damage the module!) - All other components use 5V from Arduino - Servo motor can draw up to 500mA - ensure adequate power supply - If servo causes Arduino to reset, use external 5V power supply for servo (remember to connect grounds together - common ground) ============================================= BREADBOARD LAYOUT SUGGESTIONS ============================================= LEFT SIDE OF BREADBOARD: - Arduino Uno positioned beside breadboard - RFID module on left section of breadboard - Power rails: Red rail = 5V, Blue rail = GND CENTER OF BREADBOARD: - LCD Display spanning center (takes significant space) - Resistors and LEDs below LCD RIGHT SIDE OF BREADBOARD: - Servo motor connections - Buzzer connections - Analog pin connections (A0, A1, A2) ============================================= WIRE COLOR CODING (SUGGESTED) ============================================= Red wires → 5V Power connections Black wires → GND (Ground) connections Orange wires → 3.3V Power (RFID only) Yellow wires → Digital signal pins Green wires → SPI communication (MOSI, MISO, SCK) Blue wires → Analog pins (A0, A1, A2) White wires → LCD data pins (D4-D7) ============================================= ASSEMBLY STEPS ============================================= 1. POWER RAILS SETUP - Connect Arduino 5V to breadboard red (+) rail - Connect Arduino GND to breadboard blue (-) rail - Connect Arduino 3.3V to separate breadboard section for RFID 2. RFID MODULE - Place RC522 module on breadboard - Connect all SPI pins (10-13) and RST (9) - DOUBLE CHECK: VCC to 3.3V (NOT 5V!) 3. LCD DISPLAY - Place LCD on breadboard (may need separate small breadboard) - Connect RS, Enable, D4, D5, D6, D7 to pins 7, 8, 2, 3, 4, 5 - Connect power (5V) and ground - Adjust contrast potentiometer until text is visible 4. SERVO MOTOR - Connect servo signal wire to pin 6 - Connect servo power (red) to 5V rail - Connect servo ground (brown/black) to GND rail - Attach barrier arm to servo horn 5. LEDs & RESISTORS - Insert 220Ω resistor in series with each LED - Green LED: Anode to A0, Cathode through resistor to GND - Red LED: Anode to A1, Cathode through resistor to GND - Check LED polarity! (Long leg = Anode +, Short leg = Cathode -) 6. BUZZER - Connect positive terminal to pin A2 - Connect negative terminal to GND 7. TESTING - Upload code to Arduino - Open Serial Monitor (9600 baud) - Test each component individually first - Scan RFID cards and verify LCD shows correct messages ============================================= SAFETY NOTES ============================================= ⚠ Never connect RFID module to 5V - use 3.3V only! ⚠ Always use current-limiting resistors with LEDs ⚠ Ensure servo motor has adequate power supply ⚠ When soldering, work in ventilated area with proper tools ⚠ Double-check all connections before powering on ⚠ Be careful with servo - barrier arm can move suddenly ============================================= TOOLS NEEDED FOR PERMANENT BUILD ============================================= □ Soldering iron (30-60W recommended) □ Solder (lead-free preferred) □ Wire strippers □ Helping hands / PCB holder □ Multimeter (for testing connections) □ Hot glue gun (for mounting components) □ Small screwdriver set □ Safety glasses ============================================= TO CREATE VISUAL DIAGRAM: ============================================= 1. Use Fritzing software (free/open-source) - Download from: fritzing.org - Import Arduino Uno, RC522, Servo, LCD components - Connect according to pin definitions above - Export as PDF or high-res PNG 2. Use TinkerCAD Circuits (web-based, free) - Go to: tinkercad.com/circuits - Drag components from library - Wire according to schematic above - Simulate circuit virtually - Export screenshot or share link 3. Hand-drawn circuit diagram - Use standard circuit symbols - Label all pins clearly - Show component values (resistor Ω) - Scan or photograph final diagram - Save as PDF ============================================= For complete project documentation visit: https://niezgodabros.com/jan/arduino-egate.html Questions? Check Arduino forums or MFRC522 library documentation =============================================