Circuit Documentation

Summary

This circuit is designed to monitor soil moisture levels and control a water pump based on the moisture readings. It uses an ESP8266 NodeMCU microcontroller to read data from a soil moisture sensor and display the information on a 16x2 I2C LCD. The microcontroller also controls a relay module to turn the water pump on or off based on the soil moisture levels. The system is connected to the internet via Wi-Fi and can be monitored and controlled using the Blynk app.

Component List

1. ESP8266 NodeMCU

   • Description: A low-cost Wi-Fi microcontroller with GPIO, ADC, and PWM capabilities.
   • 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

2. 16x2 I2C LCD

   • Description: A 16x2 character LCD display with I2C interface.
   • Pins: GND, VCC, SDA, SCL

3. 5V Mini Water Pump

   • Description: A small water pump operating at 5V.
   • Pins: Positive pin, Negative pin

4. Relay Module 5V-30V

   • Description: A relay module that can be triggered by a 5V signal to switch higher voltage loads.
   • Pins: Common contact, Normally open, Normally closed, Trigger, V-, V+

5. 9V Battery

   • Description: A standard 9V battery for powering the water pump.
   • Pins: +, -

6. Soil Moisture Sensor

   • Description: A sensor to measure the moisture content in the soil.
   • Pins: VCC, GND, SIG

Wiring Details

ESP8266 NodeMCU

• D0: Connected to Relay module (Trigger)
• D1: Connected to 16x2 I2C LCD (SCL)
• D2: Connected to 16x2 I2C LCD (SDA)
• 3V3: Connected to Relay module (V+), Soil Moisture Sensor (VCC), and 16x2 I2C LCD (VCC)
• GND: Connected to Relay module (V-), Soil Moisture Sensor (GND), and 16x2 I2C LCD (GND)
• A0: Connected to Soil Moisture Sensor (SIG)

16x2 I2C LCD

• GND: Connected to ESP8266 NodeMCU (GND)
• VCC: Connected to ESP8266 NodeMCU (3V3)
• SDA: Connected to ESP8266 NodeMCU (D2)
• SCL: Connected to ESP8266 NodeMCU (D1)

5V Mini Water Pump

• Positive pin: Connected to 9V Battery (+)
• Negative pin: Connected to Relay module (Normally open)

Relay Module 5V-30V

• Common contact: Connected to 9V Battery (-)
• Normally open: Connected to 5V Mini Water Pump (Negative pin)
• Trigger: Connected to ESP8266 NodeMCU (D0)
• V-: Connected to ESP8266 NodeMCU (GND)
• V+: Connected to ESP8266 NodeMCU (3V3)

9V Battery

• +: Connected to 5V Mini Water Pump (Positive pin)
• -: Connected to Relay module (Common contact)

Soil Moisture Sensor

• VCC: Connected to ESP8266 NodeMCU (3V3)
• GND: Connected to ESP8266 NodeMCU (GND)
• SIG: Connected to ESP8266 NodeMCU (A0)

Documented Code

#define BLYNK_TEMPLATE_ID "TMPL6mU3PuwAw"
#define BLYNK_TEMPLATE_NAME "MyProject"
#define BLYNK_PRINT Serial
#include <LiquidCrystal_I2C.h>
#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>
#include <DHT.h>
#include <Wire.h>

// Initialize the LCD display
LiquidCrystal_I2C lcd(0x27, 16, 2);
// Wi-Fi credentials
char auth[] = "0C8Pt-X2iftjL3-Gdq9y6Q-WNVJoncjg";
char ssid[] = "mohan";
char pass[] = "1234567890";

BlynkTimer timer;
bool Relay = 0;
bool isBlocked = true;
bool automaticControlEnabled = true;
int value = 0;

// Water pump control pin
#define sensor A0
#define WATER_PUMP_PIN D0
#define SOIL_MOISTURE_THRESHOLD 30  // Adjust this threshold value as needed

// Function prototypes
void soilMoistureSensor();
BLYNK_WRITE(V1);
BLYNK_WRITE(V3);

void setup() {
    Serial.begin(115200);
    pinMode(WATER_PUMP_PIN, OUTPUT);
    digitalWrite(WATER_PUMP_PIN, HIGH);
    lcd.begin();
    lcd.backlight();
    
    // Connect to Wi-Fi
    WiFi.begin(ssid, pass);
    while (WiFi.status() != WL_CONNECTED) {
        delay(1000);
        Serial.println("Connecting to WiFi...");
    }
    Serial.println("Connected to WiFi");

    // Initialize Blynk
    Blynk.begin(auth, ssid, pass, "blynk.cloud", 80);
    Blynk.virtualWrite(V3, 1);
    lcd.setCursor(1, 0);
    lcd.print("System Loading");
    for (int a = 0; a <= 15; a++) {
      lcd.setCursor(a, 1);
      lcd.print(".");
      delay(500);
    }
    lcd.clear();

    // Call the function
    timer.setInterval(100L, soilMoistureSensor); 
}

// Blynk virtual pin handler for water pump control

// Get the soil moisture values
void soilMoistureSensor() {
    int value = analogRead(sensor);
    value = map(value, 0, 1024, 0, 100);
    value = (value - 100) * -1;

    Blynk.virtualWrite(V0, value);
    lcd.setCursor(0, 0);
    lcd.print("Moisture :");
    lcd.print(value);
    lcd.print(" ");
if (automaticControlEnabled) {

    // Check if soil moisture is below the threshold
    if (value < SOIL_MOISTURE_THRESHOLD) {
        // If below threshold, turn on the water pump
        if (!Relay) {
            digitalWrite(WATER_PUMP_PIN, HIGH);  // Assuming LOW activates the relay or pump
            Relay = 1;
            Blynk.virtualWrite(V2, 1);  // Update Blynk app to reflect the pump status
            Serial.println("Water pump turned ON");
        }
    } else {
        // If above or equal to threshold, turn off the water pump
        if (Relay) {
            digitalWrite(WATER_PUMP_PIN, LOW);  // Assuming HIGH deactivates the relay or pump
            Relay = 0;
            Blynk.virtualWrite(V2, 0);  // Update Blynk app to reflect the pump status
            Serial.println("Water pump turned OFF");
        }
    }
}
}
BLYNK_WRITE(V1) {
    // Callback for changes in Button V3 state
    if (isBlocked) {
        // Button V1 is blocked, do nothing
    } else {
        int waterPumpStatus = param.asInt();
        
        if (waterPumpStatus == 1) {
            digitalWrite(WATER_PUMP_PIN, HIGH);  // Assuming HIGH is ON and LOW is OFF
            Serial.println("Water pump turned ON");
            Blynk.virtualWrite(V2, 1);
        } else {
            digitalWrite(WATER_PUMP_PIN, LOW);   // Assuming HIGH is ON and LOW is OFF
            Serial.println("Water pump turned OFF");
            Blynk.virtualWrite(V2, 0);
        }
    }
}

BLYNK_WRITE(V3) {
    int restartButtonState = param.asInt();

    if (restartButtonState == 1) {
        Serial.println("Restart AUTO MOOD...");
        ESP.restart();
        Blynk.virtualWrite(V3, 1);
        isBlocked = true;
    } else {
        // Callback for changes in Button V3 state
        automaticControlEnabled = param.asInt();
        int enableDisableButtonState = param.asInt();
        automaticControlEnabled = enableDisableButtonState == 1;
        Blynk.virtualWrite(V3, automaticControlEnabled ? 1 : 0);
        Blynk.virtualWrite(V3, 0);
        Blynk.virtualWrite(V2, 0);
        digitalWrite(WATER_PUMP_PIN, LOW);  // Assuming HIGH deactivates the relay or pump
        Relay = 0;
        is