Circuit Documentation

Summary

This circuit is designed to monitor and control environmental parameters for applications such as smart plant systems. It includes sensors for measuring temperature, humidity, soil moisture, and motion detection. The system uses an Arduino UNO as the primary microcontroller for sensor data acquisition and control logic, interfacing with an LCD display for real-time data output. An ESP32 microcontroller is included for wireless communication capabilities, potentially to interface with IoT platforms like Blynk for remote monitoring. A battery case provides power to the system, ensuring portability and ease of deployment.

Component List

Arduino UNO

• Microcontroller board based on the ATmega328P
• Used for controlling sensors, LCD display, and relay

ESP32 (30 pin)

• Microcontroller with Wi-Fi and Bluetooth capabilities
• Used for IoT connectivity and remote data transmission

LCD Display 16x2

• Alphanumeric liquid crystal display
• Displays temperature, humidity, and soil moisture data

My battery case

• Power supply unit for the circuit
• Provides a portable power source

KY-015 DHT11

• Temperature and humidity sensor
• Measures ambient temperature and humidity

Soil Moisture Sensor

• Detects the moisture level in the soil
• Used to monitor and control watering systems

PIR Sensor

• Motion detector sensor
• Detects the presence of humans or animals in the vicinity

LDR (Light Dependent Resistor)

• Measures the intensity of light
• Can be used to monitor environmental light conditions

Wiring Details

Arduino UNO

• 5V connected to LCD Display (LEDA, VDD), KY-015 DHT11 (5V), PIR Sensor (VCC), LDR (VCC), Soil Moisture Sensor (VCC)
• GND connected to ESP32 (GND), My battery case (-), LCD Display (LEDK, RW, VSS), KY-015 DHT11 (GND), PIR Sensor (GND), LDR (GND), Soil Moisture Sensor (GND)
• Vin connected to ESP32 (Vin), My battery case (+)
• A0 connected to Soil Moisture Sensor (SIG)
• A1 connected to LDR (A0)
• D12 connected to LCD Display (DB7)
• D11 connected to LCD Display (DB6)
• D10 connected to LCD Display (DB5)
• D9 connected to LCD Display (DB4)
• D8 connected to LCD Display (E)
• D7 connected to LCD Display (RS)
• D3 connected to PIR Sensor (Data)
• D2 connected to KY-015 DHT11 (S)
• D1 connected to ESP32 (RX0)
• D0 connected to ESP32 (TX0)

ESP32 (30 pin)

• GND connected to Arduino UNO (GND), My battery case (-)
• Vin connected to Arduino UNO (Vin), My battery case (+)
• RX0 connected to Arduino UNO (D1)
• TX0 connected to Arduino UNO (D0)

LCD Display 16x2

• LEDA and VDD connected to Arduino UNO (5V)
• LEDK, RW, and VSS connected to Arduino UNO (GND)
• DB7 connected to Arduino UNO (D12)
• DB6 connected to Arduino UNO (D11)
• DB5 connected to Arduino UNO (D10)
• DB4 connected to Arduino UNO (D9)
• E connected to Arduino UNO (D8)
• RS connected to Arduino UNO (D7)

KY-015 DHT11

• 5V connected to Arduino UNO (5V)
• S connected to Arduino UNO (D2)
• GND connected to Arduino UNO (GND)

Soil Moisture Sensor

• VCC connected to Arduino UNO (5V)
• GND connected to Arduino UNO (GND)
• SIG connected to Arduino UNO (A0)

PIR Sensor

• VCC connected to Arduino UNO (5V)
• GND connected to Arduino UNO (GND)
• Data connected to Arduino UNO (D3)

LDR

• VCC connected to Arduino UNO (5V)
• GND connected to Arduino UNO (GND)
• A0 connected to Arduino UNO (A1)

Documented Code

Arduino UNO Code

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <DHT.h>

#define DHTPIN 2      // Pin where DHT11 is connected
#define DHTTYPE DHT11
DHT dht(DHTPIN, DHTTYPE);

#define soilMoisturePin A0
#define relayPin 8
#define pirPin 3

LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  lcd.begin();
  lcd.backlight();
  
  pinMode(relayPin, OUTPUT);
  pinMode(pirPin, INPUT);
  
  dht.begin();
  lcd.setCursor(0, 0);
  lcd.print("Smart Plant");
  delay(2000);
}

void loop() {
  float temp = dht.readTemperature();
  float humidity = dht.readHumidity();
  int soilMoistureValue = analogRead(soilMoisturePin);
  int motionDetected = digitalRead(pirPin);

  // Display sensor data on LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("T:"); lcd.print(temp); lcd.print("C");
  lcd.setCursor(0, 1);
  lcd.print("H:"); lcd.print(humidity); lcd.print("%");
  lcd.setCursor(8, 1);
  lcd.print("M:"); lcd.print(soilMoistureValue);

  // Control water pump based on soil moisture
  if (soilMoistureValue < 400) {   // Adjust threshold as needed
    digitalWrite(relayPin, LOW);  // Activate pump (LOW because relay is active LOW)
  } else {
    digitalWrite(relayPin, HIGH);  // Deactivate pump
  }

  delay(2000);  // Wait for 2 seconds before repeating
}

ESP32 Code

#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>

char auth[] = "YourBlynkAuthToken";
char ssid[] = "YourWiFiSSID";
char pass[] = "YourWiFiPassword";

BlynkTimer timer;

void sendSensorData() {
  // Send sensor data to Blynk
  Blynk.virtualWrite(V1, dht.readTemperature());
  Blynk.virtualWrite(V2, dht.readHumidity());
  Blynk.virtualWrite(V3, analogRead(soilMoisturePin));
  Blynk.virtualWrite(V4, digitalRead(pirPin));
}

void setup() {
  Serial.begin(9600);
  Blynk.begin(auth, ssid, pass);

  timer.setInterval(2000L, sendSensorData);
}

void loop() {
  Blynk.run();
  timer.run();
}

(Note: The ESP32 code references variables and functions such as dht.readTemperature() and analogRead(soilMoisturePin) which are not defined within the provided code snippet. These would typically be defined in the same manner as in the Arduino UNO code, or the ESP32 would need to be programmed to receive this data from the Arduino UNO via serial communication or another protocol.)