Circuit Documentation

Summary

This circuit integrates an Arduino UNO microcontroller with a 4x4 membrane matrix keypad, an LCD screen with I2C interface, a 1-channel 5V relay module, and an LED bulb for AC control. The circuit is powered by a mini AC-DC converter module that steps down mains voltage to 5V. A diode is used for protection in the power supply circuit. The relay module controls the LED bulb, and the keypad provides user input to the Arduino, which in turn displays information on the LCD screen.

Component List

Arduino UNO

• Microcontroller board based on the ATmega328P
• Provides digital I/O pins, analog inputs, and various power outputs

4X4 Membrane Matrix Keypad

• Provides a 4x4 matrix of buttons for user input
• Each row and column is connected to a digital pin on the Arduino

LCD screen 16x2 I2C

• Alphanumeric liquid crystal display with 16 characters by 2 lines
• Uses I2C communication to interface with the Arduino

1 Channel 5V Relay Module

• Electromechanical switch with one normally open (N.O.) contact
• Controlled by an Arduino digital output

Diode

• Semiconductor device that allows current to flow in one direction only
• Used for protecting the circuit from reverse voltage

LED bulb AC / Bombillo AC

• Light-emitting diode bulb designed for AC power
• Controlled by the relay module

Mini AC-DC 110V-230V to 5V 700mA Module

• Power supply module that converts AC mains voltage to 5V DC
• Powers the Arduino and other 5V components

Ac Supply

• Provides the mains voltage to the circuit
• Connected to the AC-DC converter and the relay module for controlling the LED bulb

MCB (Miniature Circuit Breaker)

• Safety device that automatically switches off electrical circuit during an overload or short circuit
• Protects the AC supply line

Wiring Details

Arduino UNO

• 5V and GND are connected to the power bus for 5V and ground distribution.
• Vin is connected to the 5V output from the mini AC-DC converter module.
• A4 (SDA) and A5 (SCL) are connected to the I2C data and clock lines of the LCD screen.
• D12 controls the relay module input.
• D10, D9, D8, D7, D6, D5, D4, D3 are connected to the rows and columns of the 4x4 keypad.

4X4 Membrane Matrix Keypad

• Rows R1 to R4 are connected to Arduino pins D10 to D7.
• Columns C1 to C4 are connected to Arduino pins D6 to D3.

LCD screen 16x2 I2C

• VCC and GND are connected to the 5V and ground power bus.
• SDA and SCL are connected to the Arduino's A4 and A5 pins.

1 Channel 5V Relay Module

• VCC+ and VCC- (GND) are connected to the 5V and ground power bus.
• IN is controlled by the Arduino's D12 pin.
• N.O. is connected to the LED bulb and COM is connected to the neutral line from the AC supply.

Diode

• Anode is connected to the 5V power bus.
• Cathode is connected to the ground power bus.

LED bulb AC / Bombillo AC

• + is connected to the MCB's OUT.
• - is connected to the relay module's N.O. contact.

Mini AC-DC 110V-230V to 5V 700mA Module

• 5v output is connected to the Arduino's Vin.
• GND is connected to the ground power bus.
• Neutral and Life are connected to the AC supply and MCB.

Ac Supply

• +ve is connected to the MCB's IN.
• -ve is connected to the neutral line of the AC-DC converter module and the relay module's COM.

MCB

• IN is connected to the AC supply's +ve.
• OUT is connected to the LED bulb and the AC-DC converter module's Life.

Documented Code

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

}

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

}

The provided code is a template with empty setup() and loop() functions, which are the entry points for Arduino sketches. The setup() function is called once when the sketch starts and is used for initializing settings, while the loop() function runs repeatedly, allowing the microcontroller to perform operations based on input or time-based events. Additional code would be required to handle the keypad input, control the relay, and update the LCD display.