Circuit Documentation

Summary of the Circuit

This circuit integrates an ESP8266 NodeMCU microcontroller with an MQ-4 gas sensor and is powered through a 2.1mm Barrel Jack with Terminal Block. The ESP8266 NodeMCU reads analog data from the MQ-4 sensor to monitor gas levels. The power for the circuit is distributed from the barrel jack to both the sensor and the microcontroller.

Component List

ESP8266 NodeMCU

• Description: A Wi-Fi microcontroller module based on the ESP8266 chipset.
• Pins: D0, D1, D2, D3, D4, 3V3, GND, D5, D6, D7, D8, RX, TX, A0, RSV, SD3, SD2, SD1, CMD, SD0, CLK, EN, RST, VIN
• Purpose: Acts as the central processing unit of the circuit, reading sensor data and providing Wi-Fi connectivity.

MQ-4 Gas Sensor

• Description: A gas sensor designed for detecting natural gas and methane levels in the air.
• Pins: A0, D0, GND, VCC
• Purpose: To detect the presence and concentration of gas in the environment.

2.1mm Barrel Jack with Terminal Block

• Description: A power connector that allows for easy connection to an external power supply.
• Pins: POS, NEG
• Purpose: To provide power to the circuit from an external source.

Wiring Details

ESP8266 NodeMCU

• A0: Connected to the A0 pin of the MQ-4 gas sensor for analog data reading.
• GND: Connected to the NEG pin of the 2.1mm Barrel Jack and the GND pin of the MQ-4 gas sensor to establish a common ground.
• VIN: Connected to the POS pin of the 2.1mm Barrel Jack to receive power.

MQ-4 Gas Sensor

• A0: Connected to the A0 pin of the ESP8266 NodeMCU for analog data output.
• GND: Connected to the NEG pin of the 2.1mm Barrel Jack and the GND pin of the ESP8266 NodeMCU to establish a common ground.
• VCC: Connected to the POS pin of the 2.1mm Barrel Jack to receive power.

2.1mm Barrel Jack with Terminal Block

• POS: Provides power to the VIN pin of the ESP8266 NodeMCU and the VCC pin of the MQ-4 gas sensor.
• NEG: Connected to the GND pins of both the ESP8266 NodeMCU and the MQ-4 gas sensor to complete the circuit.

Documented Code

There is no code provided for the microcontroller in this circuit. The ESP8266 NodeMCU would typically be programmed to read the analog signal from the MQ-4 sensor, process the data, and possibly send the information to a server or display it locally. However, without the provided code, this section cannot be documented further.