Circuit Documentation

Summary of the Circuit

This circuit is designed around the Arduino UNO microcontroller, which serves as the central processing unit for various sensors and input/output devices. The circuit includes a DHT11 temperature and humidity sensor, an MQ-2 gas sensor, an HC-SR501 motion sensor, a membrane matrix keypad for user input, and a buzzer module for audio feedback. The sensors and the keypad provide input to the Arduino, which processes the data and can trigger the buzzer based on certain conditions. The circuit is powered by the Arduino's 5V output, and all components share a common ground.

Component List

Arduino UNO

• Microcontroller board based on the ATmega328P
• Provides digital and analog I/O pins
• Powers the circuit and processes sensor data

DHT11 Sensor V2

• Digital temperature and humidity sensor
• Provides ambient temperature and humidity readings

MQ-2 SENSOR

• Combustible gas and smoke sensor
• Provides analog and digital outputs indicating gas presence

Membrane Matrix Keypad

• Input device with rows and columns of buttons
• Allows user interaction with the circuit

Buzzer Module

• Audio signaling device
• Can produce a tone when activated

HC-SR501 Motion sensor

• Passive infrared sensor for detecting motion
• Provides a digital output when motion is detected

Wiring Details

Arduino UNO

• 5V pin connected to the VCC pins of DHT11 Sensor V2, MQ-2 SENSOR, HC-SR501 Motion sensor, and Buzzer Module
• GND pin connected to the GND pins of DHT11 Sensor V2, MQ-2 SENSOR, HC-SR501 Motion sensor, and Buzzer Module
• A0 pin connected to the A0 pin of MQ-2 SENSOR
• D12 pin connected to the OUT pin of HC-SR501 Motion sensor
• D11 pin connected to the I/O pin of Buzzer Module
• D10 pin connected to the DAT pin of DHT11 Sensor V2
• D9 to D3 pins connected to the Row 1 to Row 4 and Column 1 to Column 3 pins of Membrane Matrix Keypad respectively
• D2 pin connected to the D0 pin of MQ-2 SENSOR

DHT11 Sensor V2

• VCC pin connected to 5V of Arduino UNO
• GND pin connected to GND of Arduino UNO
• DAT pin connected to D10 of Arduino UNO

MQ-2 SENSOR

• VCC pin connected to 5V of Arduino UNO
• GND pin connected to GND of Arduino UNO
• A0 pin connected to A0 of Arduino UNO
• D0 pin connected to D2 of Arduino UNO

Membrane Matrix Keypad

• Row 1 to Row 4 pins connected to D9 to D6 of Arduino UNO respectively
• Column 1 to Column 3 pins connected to D5 to D3 of Arduino UNO respectively

Buzzer Module

• Vcc pin connected to 5V of Arduino UNO
• GND pin connected to GND of Arduino UNO
• I/O pin connected to D11 of Arduino UNO

HC-SR501 Motion sensor

• VCC pin connected to 5V of Arduino UNO
• GND pin connected to GND of Arduino UNO
• OUT pin connected to D12 of Arduino UNO

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 setup configurations and operational logic based on the desired behavior of the circuit.