Circuit Documentation

Summary

This document provides a detailed overview of a circuit designed to interface various components with an Arduino UNO microcontroller. The circuit includes a servo motor, a buzzer, an MQ-4 gas sensor, a temperature sensor (LM35), a SIM800L GSM module, a 5V relay module, a fan, a MOSFET, an ESP8266 ESP-01 WiFi module, a 5V battery, a rocker switch, and an I2C LCD 16x2 screen. The Arduino UNO serves as the central processing unit, controlling the components and facilitating communication between them.

Component List

• Arduino UNO: A microcontroller board based on the ATmega328P, featuring digital and analog I/O pins.
• Servo: An actuator that can be precisely controlled for angular rotation.
• Buzzer: An electronic component that emits sound when powered.
• MQ-4 Gas Sensor: A sensor for detecting methane and natural gas in the air.
• Resistor (10 Ohms): A passive two-terminal electrical component that implements electrical resistance.
• Temperature Sensor (LM35): A precision integrated-circuit temperature sensor with an output voltage linearly proportional to the Centigrade temperature.
• SIM800L GSM Module: A cellular communication module for making calls, sending messages, and connecting to the internet.
• 1 Channel 5V Relay Module: An electrically operated switch that allows you to turn on or off a circuit using voltage and/or current much higher than a microcontroller can handle.
• Fan: An electric device that creates airflow.
• MOSFET: A type of field-effect transistor used for amplifying or switching electronic signals.
• ESP8266 ESP-01 WiFi Module: A self-contained SOC with integrated TCP/IP protocol stack that can give any microcontroller access to a WiFi network.
• 5V Battery: A power source providing a 5V output.
• Rocker Switch: A switch that rocks back and forth to open or close the circuit.
• I2C LCD 16x2 Screen: A liquid-crystal display capable of displaying 16 characters per line, with 2 lines, using the I2C communication protocol.

Wiring Details

Arduino UNO

• 3.3V to ESP8266 ESP-01 WiFi Module (CH_PD and VCC)
• 5V to I2C LCD 16x2 Screen (VCC), Fan, Servo (VCC), SIM800L GSM Module (VCC), MQ-4 Gas Sensor (VCC)
• GND to I2C LCD 16x2 Screen, Servo, Buzzer, MQ-4 Gas Sensor, Temperature Sensor (LM35), 1 Channel 5V Relay Module, ESP8266 ESP-01 WiFi Module, SIM800L GSM Module
• Vin to 1 Channel 5V Relay Module (VCC+)
• A0 to MQ-4 Gas Sensor (A0)
• A1 to Temperature Sensor (LM35) (Vout)
• A4 to I2C LCD 16x2 Screen (SDA)
• A5 to I2C LCD 16x2 Screen (SCL)
• D2 to 1 Channel 5V Relay Module (IN)
• D3 to SIM800L GSM Module (RXD), ESP8266 ESP-01 WiFi Module (RXD)
• D4 to SIM800L GSM Module (RST)
• D8 to Buzzer (PIN)
• D9 to Servo (PWM)
• D10 to Resistor (pin1)

Servo

• VCC to Arduino UNO (5V)
• GND to Arduino UNO (GND)
• PWM to Arduino UNO (D9)

Buzzer

• PIN to Arduino UNO (D8)
• GND to Arduino UNO (GND)

MQ-4 Gas Sensor

• A0 to Arduino UNO (A0)
• VCC to Arduino UNO (5V)
• GND to Arduino UNO (GND)

Resistor (10 Ohms)

• Pin1 to Arduino UNO (D10)
• Pin2 to MOSFET (Gate)

Temperature Sensor (LM35)

• +Vs to Arduino UNO (GND)
• Vout to Arduino UNO (A1)
• GND to Arduino UNO (GND)

SIM800L GSM Module

• VCC to Arduino UNO (5V)
• GND to Arduino UNO (GND)
• RST to Arduino UNO (D4)
• RXD to Arduino UNO (D3)
• TXD to 1 Channel 5V Relay Module (IN)

1 Channel 5V Relay Module

• VCC+ to Arduino UNO (Vin)
• VCC- (GND) to Arduino UNO (GND)
• IN to Arduino UNO (D2)

Fan

• 5V to Arduino UNO (5V)
• GND to MOSFET (Drain)

MOSFET

• Gate to Resistor (pin2)
• Drain to Fan (GND)
• Source to Arduino UNO (GND)

ESP8266 ESP-01 WiFi Module

• TXD to Arduino UNO (D2)
• RXD to Arduino UNO (D3)
• CH_PD to Arduino UNO (3.3V)
• VCC to Arduino UNO (3.3V)
• GND to Arduino UNO (GND)

5V Battery

• Positive to 1 Channel 5V Relay Module (VCC+)
• Negative to Rocker Switch (input)

Rocker Switch

• Input to 5V Battery (negative)
• Output to 1 Channel 5V Relay Module (VCC-)

I2C LCD 16x2 Screen

• SDA to Arduino UNO (A4)
• SCL to Arduino UNO (A5)
• VCC (5V) to Arduino UNO (5V)
• GND to Arduino UNO (GND)

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 contain any functional code. It is expected that the user will fill in the setup and loop functions with the necessary code to control the circuit components.