Circuit Documentation

Summary

This circuit integrates an Arduino UNO microcontroller with an RFID-RC522 module, a 5V relay, and an HC-05 Bluetooth module. The Arduino UNO serves as the central processing unit, interfacing with the RFID module for tag reading capabilities, controlling the relay for power switching applications, and communicating with external devices via the Bluetooth module. The circuit is designed to operate with a 3.3V and 5V power supply from the Arduino UNO, with ground connections distributed across all components for a common reference point.

Component List

Arduino UNO

• Description: A microcontroller board based on the ATmega328P.
• Purpose: Acts as the central controller for the circuit, interfacing with all other components.
• Pins: UNUSED, IOREF, Reset, 3.3V, 5V, GND, Vin, Analog (A0-A5), I2C (SCL, SDA), AREF, Digital (D0-D13).

RFID-RC522

• Description: An RFID reader/writer module.
• Purpose: To read RFID tags and communicate the data to the Arduino UNO.
• Pins: VCC (3.3V), RST, GND, IRQ, MISO, MOSI, SCK, SDA.

5V Relay

• Description: An electromechanical switch that can be controlled with a low voltage signal.
• Purpose: To switch higher power circuits on and off using the Arduino's digital output.
• Pins: Normally Open, Common terminal, Normally Closed, In, GND, VCC.

HC-05 Bluetooth Module

• Description: A Bluetooth module for wireless communication.
• Purpose: To enable wireless communication between the Arduino and other Bluetooth-enabled devices.
• Pins: Key, VCC, TXD, RXD, State, GND.

Wiring Details

Arduino UNO

• 3.3V connected to RFID-RC522 VCC (3.3V) and HC-05 Bluetooth Module VCC.
• 5V connected to 5V relay VCC.
• GND connected to HC-05 Bluetooth Module GND, RFID-RC522 GND, and 5V relay GND.
• A5 connected to 5V relay In.
• D13 connected to RFID-RC522 SCK.
• D12 connected to RFID-RC522 MISO.
• D11 connected to RFID-RC522 MOSI.
• D10 connected to RFID-RC522 SDA.
• D9 connected to RFID-RC522 RST.
• D3 connected to HC-05 Bluetooth Module RXD.
• D2 connected to HC-05 Bluetooth Module TXD.

RFID-RC522

• VCC (3.3V) connected to Arduino UNO 3.3V.
• RST connected to Arduino UNO D9.
• GND connected to Arduino UNO GND.
• IRQ not connected.
• MISO connected to Arduino UNO D12.
• MOSI connected to Arduino UNO D11.
• SCK connected to Arduino UNO D13.
• SDA connected to Arduino UNO D10.

5V Relay

• VCC connected to Arduino UNO 5V.
• In connected to Arduino UNO A5.
• GND connected to Arduino UNO GND.
• Normally Open, Common terminal, and Normally Closed are available for external circuit connections.

HC-05 Bluetooth Module

• VCC connected to Arduino UNO 3.3V.
• TXD connected to Arduino UNO D2.
• RXD connected to Arduino UNO D3.
• GND connected to Arduino UNO GND.
• Key and State are available for additional functionality and status indication.

Documented Code

Arduino UNO Code (sketch.ino)

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

}

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

}

Note: The provided code is a template and does not include specific functionality. It should be populated with the setup and loop routines required for the intended operation of the circuit.