Circuit Documentation

Summary

This document provides a detailed overview of a circuit designed to monitor air quality and environmental conditions using various sensors and an ESP32 microcontroller. The circuit includes air quality sensors (MQ-135 and MQ-2), a temperature and humidity sensor (DHT11), multiple LEDs for status indication, and a piezo buzzer for audible alerts. The ESP32 microcontroller serves as the central processing unit, interfacing with all sensors and output devices.

Component List

1. MQ-135 SENSOR AIR QUALITY

   • Pins: VCC, GND, A0, D0
   • Description: Air quality sensor for detecting gases like NH3, NOx, alcohol, benzene, smoke, and CO2.
   • Purpose in Circuit: Measures air quality and sends analog data to the ESP32.

2. MQ-2 SENSOR

   • Pins: VCC, GND, A0, D0
   • Description: Gas sensor for detecting LPG, i-butane, propane, methane, alcohol, hydrogen, and smoke.
   • Purpose in Circuit: Measures gas concentration and sends analog data to the ESP32.

3. DHT11 Sensor V2

   • Pins: GND, DAT, VCC
   • Description: Temperature and humidity sensor.
   • Purpose in Circuit: Measures temperature and humidity and sends digital data to the ESP32.

4. ESP32 (30 pin)

   • Pins: EN, VP, VN, D34, D35, D32, D33, D25, D26, D27, D14, D12, D13, GND, Vin, D23, D22, TX0, RX0, D21, D19, D18, D5, TX2, RX2, D4, D2, D15, 3V3
   • Description: Microcontroller with Wi-Fi and Bluetooth capabilities.
   • Purpose in Circuit: Central processing unit that interfaces with all sensors and output devices.

5. LED: Two Pin (orange)

   • Pins: cathode, anode
   • Description: Orange LED for visual indication.
   • Purpose in Circuit: Provides visual status indication.

6. LED: Two Pin (blue)

   • Pins: cathode, anode
   • Description: Blue LED for visual indication.
   • Purpose in Circuit: Provides visual status indication.

7. LED: Two Pin (green)

   • Pins: cathode, anode
   • Description: Green LED for visual indication.
   • Purpose in Circuit: Provides visual status indication.

8. LED: Two Pin (red)

   • Pins: cathode, anode
   • Description: Red LED for visual indication.
   • Purpose in Circuit: Provides visual status indication.

9. Piezo Buzzer

   • Pins: pin 1, pin 2
   • Description: Buzzer for audible alerts.
   • Purpose in Circuit: Provides audible alerts.

Wiring Details

MQ-135 SENSOR AIR QUALITY

• VCC connected to 3V3 of ESP32
• GND connected to GND of ESP32
• A0 connected to D35 of ESP32

MQ-2 SENSOR

• VCC connected to 3V3 of ESP32
• GND connected to GND of ESP32
• A0 connected to D34 of ESP32

DHT11 Sensor V2

• GND connected to GND of ESP32
• DAT connected to D4 of ESP32
• VCC connected to 3V3 of ESP32

ESP32 (30 pin)

• D4 connected to DAT of DHT11 Sensor V2
• GND connected to GND of Piezo Buzzer, MQ-135 SENSOR AIR QUALITY, MQ-2 SENSOR, DHT11 Sensor V2, LED: Two Pin (orange), LED: Two Pin (green), LED: Two Pin (red), LED: Two Pin (blue)
• 3V3 connected to VCC of MQ-135 SENSOR AIR QUALITY, MQ-2 SENSOR, DHT11 Sensor V2
• D35 connected to A0 of MQ-135 SENSOR AIR QUALITY
• D34 connected to A0 of MQ-2 SENSOR
• D32 connected to anode of LED: Two Pin (orange)
• D33 connected to anode of LED: Two Pin (green)
• D25 connected to anode of LED: Two Pin (red)
• D26 connected to anode of LED: Two Pin (blue)
• D2 connected to pin 1 of Piezo Buzzer

LED: Two Pin (orange)

• cathode connected to GND of ESP32
• anode connected to D32 of ESP32

LED: Two Pin (blue)

• cathode connected to GND of ESP32
• anode connected to D26 of ESP32

LED: Two Pin (green)

• cathode connected to GND of ESP32
• anode connected to D33 of ESP32

LED: Two Pin (red)

• cathode connected to GND of ESP32
• anode connected to D25 of ESP32

Piezo Buzzer

• pin 1 connected to D2 of ESP32
• pin 2 connected to GND of ESP32

Code

No code is provided for this circuit.