Circuit Documentation

Summary

This circuit integrates various components including a NodeMCU V3 ESP8266, an Arduino UNO, an HC-SR04 Ultrasonic Sensor, an MQ-5 gas sensor, an LCD 16x2 display, a rotary potentiometer, a red LED, a piezo buzzer, and a battery. The circuit is designed to interface these components to perform specific tasks, with the Arduino UNO acting as the primary microcontroller.

Component List

1. NodeMCU V3 ESP8266

   • Pins: A0, GND, VU, S3, S2, S1, SC, S0, SK, 3V3, EN, RST, Vin, D0, D1, D2, D3, D4, D5, D6, D7, D8, RX, TX
   • Description: A low-cost Wi-Fi microcontroller with GPIO, ADC, and PWM capabilities.

2. HC-SR04 Ultrasonic Sensor

   • Pins: VCC, TRIG, ECHO, GND
   • Description: A sensor used to measure distance using ultrasonic waves.

3. MQ-5 Gas Sensor

   • Pins: VCC, GND, Digi Out, Analog out
   • Description: A gas sensor used to detect LPG, natural gas, and coal gas.

4. Battery

   • Pins: -, +
   • Description: Provides power to the circuit.

5. LED: Two Pin (red)

   • Pins: Cathode, Anode
   • Description: A red LED used for visual indication.

6. Piezo Buzzer

   • Pins: Pin 1, Pin 2
   • Description: A buzzer used for sound indication.

7. LCD 16x2 (Wokwi Compatible)

   • Pins: VSS, VDD, V0, RS, RW, E, D0, D1, D2, D3, D4, D5, D6, D7, A, K
   • Description: A 16x2 character LCD display.

8. Rotary Potentiometer

   • Pins: Leg1, Wiper, Leg2
   • Description: A variable resistor used to adjust voltage.
   • Properties: Resistance: 10k Ohms

9. Arduino UNO

   • Pins: UNUSED, IOREF, Reset, 3.3V, 5V, GND, Vin, A0, A1, A2, A3, A4, A5, SCL, SDA, AREF, D13, D12, D11, D10, D9, D8, D7, D6, D5, D4, D3, D2, D1, D0
   • Description: A popular microcontroller board based on the ATmega328P.

10. Resistor (200 Ohms)

    • Pins: Pin1, Pin2
    • Description: A resistor used to limit current.
    • Properties: Resistance: 200 Ohms

Wiring Details

NodeMCU V3 ESP8266

• GND connected to the common ground.
• 3V3 connected to the 5V power rail.
• RX connected to Arduino UNO D1.
• TX connected to Arduino UNO D0.

HC-SR04 Ultrasonic Sensor

• VCC connected to the 5V power rail.
• GND connected to the common ground.
• TRIG connected to Arduino UNO D9.
• ECHO connected to Arduino UNO D8.

MQ-5 Gas Sensor

• VCC connected to the 5V power rail.
• GND connected to the common ground.
• Analog out connected to Arduino UNO A0.

Battery

• - connected to the common ground.
• + connected to the 5V power rail.

LED: Two Pin (red)

• Cathode connected to the common ground.
• Anode connected to Resistor pin2.

Piezo Buzzer

• Pin 1 connected to Arduino UNO D10.
• Pin 2 connected to the common ground.

LCD 16x2 (Wokwi Compatible)

• VSS connected to the common ground.
• VDD connected to the 5V power rail.
• V0 connected to Rotary Potentiometer wiper.
• RS connected to Arduino UNO D12.
• RW connected to the common ground.
• E connected to Arduino UNO D11.
• D4 connected to Arduino UNO D5.
• D5 connected to Arduino UNO D4.
• D6 connected to Arduino UNO D3.
• D7 connected to Arduino UNO D2.
• A connected to Resistor pin2.
• K connected to the common ground.

Rotary Potentiometer

• Leg1 connected to the common ground.
• Wiper connected to LCD 16x2 V0.
• Leg2 connected to the 5V power rail.

Arduino UNO

• GND connected to the common ground.
• 5V connected to the 5V power rail.
• A0 connected to MQ-5 Analog out.
• D0 connected to NodeMCU V3 ESP8266 TX.
• D1 connected to NodeMCU V3 ESP8266 RX.
• D2 connected to LCD 16x2 D7.
• D3 connected to LCD 16x2 D6.
• D4 connected to LCD 16x2 D5.
• D5 connected to LCD 16x2 D4.
• D6 connected to Resistor pin1.
• D8 connected to HC-SR04 ECHO.
• D9 connected to HC-SR04 TRIG.
• D10 connected to Piezo Buzzer pin 1.
• D11 connected to LCD 16x2 E.
• D12 connected to LCD 16x2 RS.

Resistor (200 Ohms)

• Pin1 connected to Arduino UNO D6.
• Pin2 connected to LED Anode.
• Pin1 connected to the 5V power rail.
• Pin2 connected to LCD 16x2 A.

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:

}

Documentation (documentation.txt)

This documentation provides a comprehensive overview of the circuit, including a summary, detailed component list, wiring details, and the code used in the microcontroller.