Circuit Documentation

Summary

This circuit integrates various components to perform a specific set of functions. The core of the circuit is an ESP32 Expansion Board, which interfaces with an RFID-RC522 module, a 4x4 Membrane Matrix Keypad, a 20x4 LCD with I2C interface, a 2-Channel Relay Module, and a 12V Solenoid Lock. The ESP32 Expansion Board is responsible for controlling the overall operation, including reading RFID tags, capturing keypad input, displaying information on the LCD, and controlling access through the solenoid lock via the relay module. The circuit is powered by a DC Source providing 9V.

Component List

ESP32 - Expansion Board

• Microcontroller board with WiFi and Bluetooth capabilities.
• Provides GPIO pins for interfacing with other components.

RFID-RC522

• RFID reader/writer module for contactless communication using 13.56MHz.
• Interfaces with the ESP32 for RFID tag reading.

12V Solenoid Lock

• Electromechanical lock that can be controlled via an electrical signal.
• Operates at 12V and is controlled by the relay module.

Lcd 20x4 i2c

• Alphanumeric LCD display with 20 characters per line and 4 lines.
• Uses I2C communication to display data from the ESP32.

4X4 Membrane Matrix Keypad

• Input device with 16 buttons arranged in a 4x4 matrix.
• Connected to the ESP32 for user input.

Relay Module 2 Channel

• Module with two independent relay channels.
• Controls high-power devices like the solenoid lock.

DC Source 9V

• Provides the power supply for the circuit.

Wiring Details

ESP32 - Expansion Board

• D32 to Keypad C4
• D33 to Keypad C3
• D25 to Keypad C2
• D26 to Keypad C1
• D27 to Keypad R4
• D14 to Keypad R3
• D12 to Keypad R2
• D13 to Keypad R1
• D23 to Relay Module IN1
• D17 to RFID-RC522 SDA
• D16 to RFID-RC522 SCK
• D4 to RFID-RC522 MOSI
• D2 to RFID-RC522 MISO
• D15 to RFID-RC522 RST
• D22 to LCD SCL
• D21 to LCD SCA
• 5V to LCD 5v and Relay Module VCC
• G to LCD GND and Relay Module GND
• V to RFID-RC522 VCC (3.3V)
• G to RFID-RC522 GND

RFID-RC522

• VCC (3.3V) to ESP32 V
• RST to ESP32 D15
• GND to ESP32 G
• IRQ (Not connected)
• MISO to ESP32 D2
• MOSI to ESP32 D4
• SCK to ESP32 D16
• SDA to ESP32 D17

12V Solenoid Lock

• VCC to Relay Module NC1
• GND to DC Source GND

Lcd 20x4 i2c

• GND to ESP32 G
• 5v to ESP32 5V
• SCA to ESP32 D21
• SCL to ESP32 D22

4X4 Membrane Matrix Keypad

• R1 to ESP32 D13
• R2 to ESP32 D12
• R3 to ESP32 D14
• R4 to ESP32 D27
• C1 to ESP32 D26
• C2 to ESP32 D25
• C3 to ESP32 D33
• C4 to ESP32 D32

Relay Module 2 Channel

• GND to ESP32 G
• IN1 to ESP32 D23
• VCC to ESP32 5V
• NC1 to Solenoid Lock VCC
• COM to DC Source VCC

DC Source 9V

• VCC to Relay Module COM
• GND to Solenoid Lock GND

Documented Code

No code has been provided for the microcontrollers in the circuit. The code would typically include initialization routines for each of the peripherals (RFID reader, keypad, LCD, relay module), as well as the main application logic to handle user input, RFID tag reading, and control of the solenoid lock. It would also manage the display output on the LCD screen.