Circuit Documentation

Summary

The circuit in question is designed to interface various sensors with an Arduino UNO and an ESP32 microcontroller for data acquisition and processing. The sensors include a light sensor, a DHT22 temperature and humidity sensor, and multiple gas sensors (MQ-4, MQ-9, MQ-135, and MKE-S08 MQ-2). Additionally, a 16x2 LCD display is included for output. The Arduino UNO serves as the central hub for sensor data collection, while the ESP32 is used for additional processing or connectivity.

Component List

Arduino UNO

• Microcontroller board based on the ATmega328P
• It has 14 digital input/output pins, 6 analog inputs, a 16 MHz quartz crystal, a USB connection, a power jack, an ICSP header, and a reset button.

ESP32 (30 pin)

• A powerful microcontroller with Wi-Fi and Bluetooth capabilities
• It has a wide variety of peripherals and is commonly used for IoT projects.

Light Sensor

• A sensor that measures ambient light intensity
• Typically used in applications where it is necessary to adjust brightness based on the surrounding light conditions.

DHT22

• A sensor that measures temperature and humidity
• Known for its reliability and accuracy for environmental monitoring.

MQ-4

• A gas sensor designed for detecting natural gas and methane
• Used in safety systems for gas leak detection.

MQ135

• A sensor for detecting a wide range of gases, including NH3, NOx, alcohol, benzene, smoke, and CO2.

MQ-9 Breakout

• A sensor that detects carbon monoxide and flammable gases
• Suitable for detecting CO and combustible gas concentrations in the air.

MKE-S08 MQ-2 Sensor

• A gas sensor for detecting LPG, propane, hydrogen, and even smoke.

LCD 16x2 (Wokwi Compatible)

• A liquid crystal display capable of displaying 16 characters per line in 2 lines
• Used for displaying sensor data or messages.

Wiring Details

Arduino UNO

• 5V and GND pins provide power to the sensors and the LCD.
• Analog pins A0 to A3 are connected to the gas sensors for analog signal reading.
• I2C pins SCL and SDA are connected to the Light Sensor for communication.
• Digital pins D0 to D12 are used for interfacing with the ESP32 and the LCD display.
• Digital pin D5 is connected to the DHT22 sensor for data output.

ESP32 (30 pin)

• Vin and GND are connected to the power rail from the Arduino UNO.
• RX0 and TX0 are connected to D0 and D1 on the Arduino UNO for serial communication.

Light Sensor

• VCC and GND are connected to the power rail.
• SCL and SDA are connected to the corresponding I2C pins on the Arduino UNO.

DHT22

• VCC and GND are connected to the power rail.
• OUT is connected to digital pin D5 on the Arduino UNO.

MQ-4, MQ135, MQ-9 Breakout, MKE-S08 MQ-2 Sensor

• VCC and GND are connected to the power rail.
• Analog output pins are connected to the respective analog pins on the Arduino UNO.
• Digital output pins (if any) are connected to the respective digital pins on the Arduino UNO.

LCD 16x2 (Wokwi Compatible)

• VDD and VSS are connected to the power rail.
• RS, RW, E, and data pins D4 to D7 are connected to digital pins D7 to D12 on the 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 for the Arduino UNO is a template with empty setup and loop functions. This code should be expanded with initialization of the connected sensors and display, as well as the main logic for reading sensor data and displaying or transmitting it.

ESP32 Code

No code was provided for the ESP32 microcontroller.

End of documentation.