Circuit Documentation

Summary

The circuit in question is designed to interface various sensors and modules with an Arduino UNO microcontroller and an ESP8266 NodeMCU module. The sensors include a DHT11 temperature and humidity sensor, a Heart Pulse Sensor, and an MQ-135 air quality sensor. Additionally, a 16x2 LCD display is used for output. The Arduino UNO is responsible for reading sensor data and controlling the LCD display, while the ESP8266 NodeMCU module is included for potential wireless communication capabilities.

Component List

Arduino UNO

• Microcontroller board based on the ATmega328P
• Features digital I/O pins, analog input pins, and various power pins
• Utilized as the main controller for interfacing with sensors and the LCD display

DHT11

• Digital temperature and humidity sensor
• Provides a digital output signal

Heart Pulse Sensor

• Sensor for measuring heart rate
• Outputs a signal that corresponds to the heartbeat

MQ-135 Sensor Air Quality

• Gas sensor for detecting a wide range of gases, including NH3, NOx, alcohol, benzene, smoke, and CO2
• Provides both analog and digital outputs

ESP8266 NodeMCU

• Wi-Fi microcontroller module based on the ESP8266
• Features digital I/O pins and a single analog input pin
• Can be used for adding wireless communication to the circuit

LCD Display 16x2

• Alphanumeric liquid crystal display
• Capable of displaying 16 characters per line across 2 lines
• Used for displaying sensor readings and messages

Wiring Details

Arduino UNO

• GND connected to the common ground net
• 5V connected to the common VCC net
• A0 connected to MQ-135 Sensor Air Quality A0
• A1 connected to Heart Pulse Sensor SIGNAL
• D12 connected to LCD Display RS
• D11 connected to LCD Display E
• D6 connected to LCD Display DB7
• D5 connected to LCD Display DB4
• D4 connected to LCD Display DB5
• D3 connected to LCD Display DB6
• D2 connected to DHT11 DATA
• D1 connected to ESP8266 NodeMCU RX

DHT11

• DATA connected to Arduino UNO D2
• GND connected to the common ground net
• VCC connected to the common VCC net

Heart Pulse Sensor

• SIGNAL connected to Arduino UNO A1
• GND connected to the common ground net
• VCC connected to the common VCC net

MQ-135 Sensor Air Quality

• A0 connected to Arduino UNO A0
• GND connected to the common ground net
• VCC connected to the common VCC net

ESP8266 NodeMCU

• RX connected to Arduino UNO D1
• GND connected to the common ground net

LCD Display 16x2

• RS connected to Arduino UNO D12
• E connected to Arduino UNO D11
• DB7 connected to Arduino UNO D6
• DB4 connected to Arduino UNO D5
• DB5 connected to Arduino UNO D4
• DB6 connected to Arduino UNO D3
• VSS (GND) connected to the common ground net
• VDD connected to the common VCC net
• RW connected to the common ground net (for write-only mode)

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. The actual implementation should include initialization of the sensors and display, as well as the main logic for reading sensor data and updating the display.

ESP8266 NodeMCU Code

No code provided for the ESP8266 NodeMCU module.

End of documentation.