Circuit Documentation

Summary

This document provides a detailed overview of a circuit that includes an ESP32 Devkit V1 microcontroller, a 16x2 I2C LCD, a DHT22 temperature and humidity sensor, an MQ-4 gas sensor, and a Mtiny Power module. The circuit is designed to read environmental data and display it on the LCD screen.

Component List

1. 16x2 I2C LCD

   • Description: A 16x2 character LCD display with I2C interface.
   • Pins: GND, VCC, SDA, SCL

2. Mtiny Power

   • Description: A power module providing 3.3V, 5V, and VIN.
   • Pins: 3V3, 5V, GND, VIN

3. DHT22

   • Description: A digital temperature and humidity sensor.
   • Pins: GND, VCC, DAT

4. ESP32 Devkit V1

   • Description: A development board featuring the ESP32 microcontroller.
   • Pins: 3V3, GND, D15, D2, D4, RX2, TX2, D5, D18, D19, D21, RX0, TX0, D22, D23, EN, VP, VN, D34, D35, D32, D33, D25, D26, D27, D14, D12, D13, VIN

5. MQ-4

   • Description: A gas sensor for detecting methane (CH4).
   • Pins: A0, D0, GND, VCC

Wiring Details

16x2 I2C LCD

• GND connected to Mtiny Power GND
• VCC connected to Mtiny Power 5V
• SDA connected to ESP32 Devkit V1 D21
• SCL connected to ESP32 Devkit V1 D22

Mtiny Power

• GND connected to:
  • ESP32 Devkit V1 GND
  • DHT22 GND
  • MQ-4 GND
  • 16x2 I2C LCD GND
• 5V connected to:
  • ESP32 Devkit V1 VIN
  • DHT22 VCC
  • MQ-4 VCC
  • 16x2 I2C LCD VCC

DHT22

• GND connected to Mtiny Power GND
• VCC connected to Mtiny Power 5V
• DAT connected to ESP32 Devkit V1 D4

ESP32 Devkit V1

• GND connected to Mtiny Power GND
• VIN connected to Mtiny Power 5V
• D2 connected to MQ-4 A0
• D4 connected to DHT22 DAT
• D21 connected to 16x2 I2C LCD SDA
• D22 connected to 16x2 I2C LCD SCL

MQ-4

• A0 connected to ESP32 Devkit V1 D2
• GND connected to Mtiny Power GND
• VCC connected to Mtiny Power 5V

Code

No code is provided for this circuit.

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This document provides a comprehensive overview of the circuit, including a summary, component list, wiring details, and code documentation. The wiring details ensure that each component is correctly connected to the power supply and the microcontroller, facilitating proper operation of the circuit.