Circuit Documentation

Summary

This document provides a detailed overview of a circuit that integrates an ESP32 microcontroller, an RFID-RC522 module, a 16x2 I2C LCD, a 7.4V battery, a 7805 voltage regulator, and a rocker switch. The circuit is designed to read RFID tags and display information on the LCD screen. The ESP32 serves as the central controller, interfacing with the RFID module and the LCD.

Component List

1. ESP32 (30 pin)

   • Description: A powerful microcontroller with built-in Wi-Fi and Bluetooth capabilities.
   • Pins: EN, VP, VN, D34, D35, D32, D33, D25, D26, D27, D14, D12, D13, GND, Vin, D23, D22, TX0, RX0, D21, D19, D18, D5, TX2, RX2, D4, D2, D15, 3V3

2. RFID-RC522

   • Description: A low-cost RFID reader module that operates at 13.56 MHz.
   • Pins: VCC (3.3V), RST, GND, IRQ, MISO, MOSI, SCK, SDA

3. 16x2 I2C LCD

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

4. 7.4V Battery

   • Description: A power source for the circuit.
   • Pins: +, -

5. 7805 Voltage Regulator

   • Description: A voltage regulator that converts 7.4V to 5V.
   • Pins: Vin, Gnd, Vout

6. Rocker Switch

   • Description: A switch to control the power supply to the circuit.
   • Pins: output, input

Wiring Details

ESP32 (30 pin)

• GND connected to:

  • 7.4V Battery (-)
  • 16x2 I2C LCD (GND)
  • 7805 Voltage Regulator (Gnd)
  • RFID-RC522 (GND)

• Vin connected to:

  • 16x2 I2C LCD (VCC)
  • Rocker Switch (output)

• D23 connected to:

  • RFID-RC522 (MOSI)

• D22 connected to:

  • RFID-RC522 (RST)
  • 16x2 I2C LCD (SCL)

• D21 connected to:

  • 16x2 I2C LCD (SDA)

• D19 connected to:

  • RFID-RC522 (MISO)

• D18 connected to:

  • RFID-RC522 (SCK)

• D5 connected to:

  • RFID-RC522 (SDA)

• 3V3 connected to:

  • RFID-RC522 (VCC (3.3V))

RFID-RC522

• VCC (3.3V) connected to:

  • ESP32 (3V3)

• RST connected to:

  • ESP32 (D22)

• GND connected to:

  • ESP32 (GND)

• MISO connected to:

  • ESP32 (D19)

• MOSI connected to:

  • ESP32 (D23)

• SCK connected to:

  • ESP32 (D18)

• SDA connected to:

  • ESP32 (D5)

16x2 I2C LCD

• GND connected to:

  • ESP32 (GND)

• VCC connected to:

  • ESP32 (Vin)

• SDA connected to:

  • ESP32 (D21)

• SCL connected to:

  • ESP32 (D22)

7.4V Battery

• + connected to:

  • 7805 Voltage Regulator (Vin)

• - connected to:

  • ESP32 (GND)

7805 Voltage Regulator

• Vin connected to:

  • 7.4V Battery (+)

• Gnd connected to:

  • ESP32 (GND)

• Vout connected to:

  • Rocker Switch (input)

Rocker Switch

• output connected to:

  • ESP32 (Vin)
  • 16x2 I2C LCD (VCC)

• input connected to:

  • 7805 Voltage Regulator (Vout)

Code

No code is provided for this circuit.

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This document provides a comprehensive overview of the circuit, including a summary, component list, wiring details, and code documentation. Each component is described in detail, and the wiring connections are clearly outlined to ensure proper assembly and functionality.