Circuit Documentation

Summary

This circuit is designed to interface with a pH meter, a turbidity sensor, and a DS18B20 temperature sensor, and display their readings through the Arduino UNO+WiFi R3 ATmega328P+Node MCU ESP8266 CH340G microcontroller. The circuit is powered by a 12V power supply, which is stepped down to 5V using an XL4015 5A DC Buck Step-down converter to power the microcontroller and sensors. The LED indicates the operational status, and resistors are used for current limiting and signal conditioning.

Component List

PH Meter

• Pins: Signal, VCC, GND
• Description: Measures the pH level of a solution.

Turbidity Sensor

• Pins: OUT, VCC, GND
• Description: Measures the turbidity of a liquid.

LED: Two Pin (red)

• Pins: cathode, anode
• Description: Provides visual indication.

DS18B20 1-Wire Temperature Sensor Probe Cable

• Pins: shield, GND, DQ, VDD
• Description: Measures temperature.

Resistor (47k Ohms)

• Pins: pin1, pin2
• Description: Limits current or divides voltage.

Resistor (4.7k Ohms)

• Pins: pin1, pin2
• Description: Used for the DS18B20 temperature sensor's data line pull-up.

XL4015 5A DC Buck Step-down

• Pins: Output +, Output -, Input +, Input -
• Description: Steps down the voltage from 12V to 5V.

Arduino UNO+WiFi R3 ATmega328P+Node MCU ESP8266 CH340G

• Pins: Multiple digital and analog pins, power, and ground.
• Description: Microcontroller board for processing and I/O interfacing.

12v Power Supply

• Pins: +, -
• Description: Provides 12V power to the circuit.

Wiring Details

PH Meter

• Signal connected to Arduino's A2
• VCC connected to Arduino's 5.0v
• GND connected to common ground net

Turbidity Sensor

• OUT connected to Arduino's A1
• VCC connected to Arduino's 5.0v
• GND connected to common ground net

LED: Two Pin (red)

• cathode connected to common ground net
• anode connected to Resistor (4.7k Ohms) pin2

DS18B20 1-Wire Temperature Sensor Probe Cable

• DQ connected to Resistor (4.7k Ohms) pin2
• VDD connected to Arduino's 5.0v
• GND connected to common ground net

Resistor (47k Ohms)

• pin1 connected to Arduino's A0
• pin2 connected to DS18B20's DQ

Resistor (4.7k Ohms)

• pin1 connected to Arduino's 3.5v
• pin2 connected to LED's anode

XL4015 5A DC Buck Step-down

• Output + connected to Arduino's VIN
• Output - connected to common ground net
• Input + connected to 12v Power Supply's +
• Input - connected to 12v Power Supply's -

12v Power Supply

• + connected to XL4015's Input +
• - connected to XL4015's Input -

Documented Code

/*
 * This Arduino Sketch reads data from a turbidity sensor, a DS18B20 temperature
 * sensor, and a pH meter. The readings are printed to the Serial Monitor.
 */

#include <OneWire.h>
#include <DallasTemperature.h>

// Pin definitions
const int turbidityPin = A1;
const int phPin = A2;
const int oneWireBus = A0;

// Setup a oneWire instance to communicate with any OneWire devices
OneWire oneWire(oneWireBus);

// Pass our oneWire reference to Dallas Temperature sensor
DallasTemperature sensors(&oneWire);

void setup() {
  // Start serial communication
  Serial.begin(9600);

  // Start up the temperature sensor library
  sensors.begin();
}

void loop() {
  // Read turbidity sensor
  int turbidityValue = analogRead(turbidityPin);
  float turbidityVoltage = turbidityValue * (5.0 / 1023.0);

  // Read pH sensor
  int phValue = analogRead(phPin);
  float phVoltage = phValue * (5.0 / 1023.0);

  // Request temperature readings
  sensors.requestTemperatures();
  float temperatureC = sensors.getTempCByIndex(0);

  // Print sensor values to Serial Monitor
  Serial.print("Turbidity Voltage: ");
  Serial.print(turbidityVoltage);
  Serial.println(" V");

  Serial.print("pH Voltage: ");
  Serial.print(phVoltage);
  Serial.println(" V");

  Serial.print("Temperature: ");
  Serial.print(temperatureC);
  Serial.println(" °C");

  // Wait 1 second before next loop
  delay(1000);
}

This code is designed to be uploaded to the Arduino UNO+WiFi R3 ATmega328P+Node MCU ESP8266 CH340G. It initializes the sensors in the setup() function and continuously reads the sensor values in the loop() function, outputting the results to the Serial Monitor.