Circuit Documentation

Summary

This circuit involves an Arduino Nano microcontroller interfacing with various components including an RFID reader, an I2C LCD display, a servo motor, a piezo buzzer, an RGB LED, and a power supply system. The circuit is designed to read RFID tags, display information on an LCD, control a servo motor, and provide visual and audio feedback using an RGB LED and a piezo buzzer.

Component List

1. Arduino Nano

   • Description: A small, complete, and breadboard-friendly board based on the ATmega328P.
   • Pins: D1/TX, D0/RX, RESET, GND, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11/MOSI, D12/MISO, VIN, 5V, A7, A6, A5, A4, A3, A2, A1, A0, AREF, 3V3, D13/SCK

2. RFID-RC522

   • Description: A low-cost RFID reader module.
   • Pins: SDA, SCK, MOSI, MISO, IRQ, GND, RST, 3.3V

3. 16x2 I2C LCD

   • Description: A 16x2 character LCD display with I2C interface.
   • Pins: GND, VCC, SDA, SCL

4. Tower Pro SG90 Servo

   • Description: A small servo motor commonly used in RC toys.
   • Pins: Signal, +5V, GND

5. Piezo Buzzer

   • Description: A simple piezoelectric buzzer for audio feedback.
   • Pins: pin 1, pin 2

6. LED: Four Pin (Common Cathode)

   • Description: An RGB LED with a common cathode.
   • Pins: red anode, common cathode, green anode, blue anode

7. 7805

   • Description: A voltage regulator that outputs 5V.
   • Pins: Vin, Gnd, Vout

8. 18650 Li-Ion

   • Description: A rechargeable lithium-ion battery.
   • Pins: Positive, Negative

9. Rocker Switch

   • Description: A simple on/off switch.
   • Pins: 1, 2

10. Resistor (200 Ohms)

    • Description: A resistor with a resistance of 200 Ohms.
    • Pins: pin1, pin2

Wiring Details

Arduino Nano

• GND: Connected to the GND of the servo motor, piezo buzzer, RFID reader, I2C LCD, RGB LED, and 7805 voltage regulator.
• D2: Connected to pin2 of a 200 Ohm resistor.
• D3: Connected to pin2 of another 200 Ohm resistor.
• D4: Connected to pin2 of another 200 Ohm resistor.
• D5: Connected to pin 1 of the piezo buzzer.
• D6: Connected to the Signal pin of the servo motor.
• D9: Connected to the RST pin of the RFID reader.
• D10: Connected to the SDA pin of the RFID reader.
• D11/MOSI: Connected to the MOSI pin of the RFID reader.
• D12/MISO: Connected to the MISO pin of the RFID reader.
• VIN: Connected to pin 1 of the rocker switch and the Vin pin of the 7805 voltage regulator.
• A5: Connected to the SCL pin of the I2C LCD.
• A4: Connected to the SDA pin of the I2C LCD.
• 3V3: Connected to the 3.3V pin of the RFID reader.
• D13/SCK: Connected to the SCK pin of the RFID reader.

RFID-RC522

• GND: Connected to the GND of the Arduino Nano.
• RST: Connected to D9 of the Arduino Nano.
• SDA: Connected to D10 of the Arduino Nano.
• MOSI: Connected to D11/MOSI of the Arduino Nano.
• MISO: Connected to D12/MISO of the Arduino Nano.
• 3.3V: Connected to the 3V3 pin of the Arduino Nano.

16x2 I2C LCD

• GND: Connected to the GND of the Arduino Nano.
• VCC: Connected to the Vout of the 7805 voltage regulator.
• SDA: Connected to A4 of the Arduino Nano.
• SCL: Connected to A5 of the Arduino Nano.

Tower Pro SG90 Servo

• GND: Connected to the GND of the Arduino Nano.
• Signal: Connected to D6 of the Arduino Nano.
• +5V: Connected to the Vout of the 7805 voltage regulator.

Piezo Buzzer

• pin 1: Connected to D5 of the Arduino Nano.
• pin 2: Connected to the GND of the Arduino Nano.

LED: Four Pin (Common Cathode)

• common cathode: Connected to the GND of the Arduino Nano.
• red anode: Connected to pin1 of a 200 Ohm resistor.
• green anode: Connected to pin1 of another 200 Ohm resistor.
• blue anode: Connected to pin1 of another 200 Ohm resistor.

7805

• Vin: Connected to pin 1 of the rocker switch.
• Gnd: Connected to the GND of the Arduino Nano.
• Vout: Connected to the +5V pin of the servo motor and the VCC pin of the I2C LCD.

18650 Li-Ion

• Positive: Connected to pin 2 of the rocker switch.
• Negative: Connected to the GND of the Arduino Nano.

Rocker Switch

• 1: Connected to the VIN pin of the Arduino Nano and the Vin pin of the 7805 voltage regulator.
• 2: Connected to the Positive pin of the 18650 Li-Ion battery.

Resistors (200 Ohms)

• Resistor 1: pin1 connected to the red anode of the RGB LED, pin2 connected to D2 of the Arduino Nano.
• Resistor 2: pin1 connected to the green anode of the RGB LED, pin2 connected to D3 of the Arduino Nano.
• Resistor 3: pin1 connected to the blue anode of the RGB LED, pin2 connected to D4 of the Arduino Nano.

Code Documentation

Arduino Nano Code

void setup() {
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:

}

This code is a basic template for the Arduino Nano. The setup() function is where you initialize your components and settings, and the loop() function is where you place the main code that runs repeatedly.

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This documentation provides a comprehensive overview of the circuit, including a detailed list of components, wiring details, and the initial code for the Arduino Nano.