Circuit Documentation

Summary

This document provides a detailed overview of a circuit designed to monitor environmental conditions and control a motor based on specific criteria. The circuit includes an ESP32 microcontroller, various sensors (DHT22, Ultrasonic Sensor, Soil Moisture Sensor), a relay, a buzzer, and a power supply unit. The ESP32 is programmed to read sensor data and control the motor based on temperature, humidity, and soil moisture levels over time.

Component List

1. ESP32 (30 pin)

   • Description: A powerful microcontroller with built-in WiFi and Bluetooth capabilities.
   • Pins: EN, VP, VN, D34, D35, D32, D33, D25, D26, D27, D14, D12, D13, GND, Vin, D23, D22, TX0, RX0, D21, D19, D18, D5, TX2, RX2, D4, D2, D15, 3V3

2. DHT22

   • Description: A digital temperature and humidity sensor.
   • Pins: +, Out, -

3. Ultrasonic Sensor

   • Description: A sensor used to measure distance by using ultrasonic waves.
   • Pins: +VCC, Trigger, Echo, GND

4. 5V Relay

   • Description: An electromechanical switch used to control high voltage devices.
   • Pins: Normally Open, Common terminal, Normally Closed, In, GND, VCC

5. Soil Moisture Module

   • Description: A module used to measure the moisture content in the soil.
   • Pins: positive, negative, Analog, Digital, Ground, VCC

6. SparkFun Soil Moisture Sensor

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

7. AC-DC PSU board 220V-5V&12V

   • Description: A power supply unit that converts 220V AC to 5V and 12V DC.
   • Pins: AC-N, AC-L, +5V, GND, +12V

8. Buzzer

   • Description: An audio signaling device.
   • Pins: PIN, GND

Wiring Details

ESP32 (30 pin)

• D34 connected to Soil Moisture Module Analog
• GND connected to AC-DC PSU board GND, Buzzer GND, DHT22 -, Ultrasonic Sensor GND, Soil Moisture Module Ground, 5V Relay GND
• D22 connected to Buzzer PIN
• D18 connected to Ultrasonic Sensor Echo
• D5 connected to Ultrasonic Sensor Trigger
• D4 connected to DHT22 Out
• D15 connected to 5V Relay In
• 3V3 connected to DHT22 +, Soil Moisture Module VCC

DHT22

• + connected to ESP32 3V3
• Out connected to ESP32 D4
• - connected to ESP32 GND

Ultrasonic Sensor

• +VCC connected to AC-DC PSU board +5V
• Trigger connected to ESP32 D5
• Echo connected to ESP32 D18
• GND connected to ESP32 GND

5V Relay

• In connected to ESP32 D15
• GND connected to ESP32 GND
• VCC connected to AC-DC PSU board +5V

Soil Moisture Module

• Analog connected to ESP32 D34
• Ground connected to ESP32 GND
• VCC connected to ESP32 3V3
• positive connected to SparkFun Soil Moisture Sensor VCC
• negative connected to SparkFun Soil Moisture Sensor GND

SparkFun Soil Moisture Sensor

• VCC connected to Soil Moisture Module positive
• GND connected to Soil Moisture Module negative

AC-DC PSU board 220V-5V&12V

• GND connected to ESP32 GND
• +5V connected to Ultrasonic Sensor +VCC, 5V Relay VCC

Buzzer

• PIN connected to ESP32 D22
• GND connected to ESP32 GND

Code Documentation

#include <WiFi.h>
#include <HTTPClient.h>

const char* ssid = "Sharath Teja";
const char* password = "SHARATH R";

unsigned long startTime;
const unsigned long dayMillis = 86400000; // Milliseconds in a day

void setup() {
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");

  // Set motor pin as output
  pinMode(motorPin, OUTPUT);
  
  startTime = millis();
}

void loop() {
  unsigned long currentTime = millis();
  unsigned long elapsedTime = currentTime - startTime;
  unsigned int days = elapsedTime / dayMillis;
  
  // Check the number of days and control motor accordingly
  if (days < 14) {
    if(temperature>30 && humidity<70 && soilmoisture<20){
        digitalWrite(motorPin, HIGH); // Turn motor ON
    } 
    else  {
        digitalWrite(motorPin, LOW); // Turn motor OFF
        }
  } 
  else if (days >= 14 && days < 28) {
    if(temperature>25 && humidity<60 && soilmoisture<40){
        digitalWrite(motorPin, HIGH); // Turn motor ON
    } 
    else  {
        digitalWrite(motorPin, LOW); // Turn motor OFF
        }
  } 
  else if (days >= 28 && days < 42) {
   if(temperature>30 && humidity<50 && soilmoisture<60){
        digitalWrite(motorPin, HIGH); // Turn motor ON
    } 
    else  {
        digitalWrite(motorPin, LOW); // Turn motor OFF
        }
  }
    else if (days >= 42 && days < 56) {
   if(temperature>30 && humidity<40 && soilmoisture<80){
        digitalWrite(motorPin, HIGH); // Turn motor ON
    } 
    else  {
        digitalWrite(motorPin, LOW); // Turn motor OFF
        }
  }
    else if (days >= 56 && days < 70) {
   if(temperature>30 && humidity<40 && soilmoisture<60){
        digitalWrite(motorPin, HIGH); // Turn motor ON
    } 
    else  {
        digitalWrite(motorPin, LOW); // Turn motor OFF
        }
  }
  delay(6000); // Update every 60 seconds
}

This code is designed to connect the ESP32 to a WiFi network and control a motor based on temperature, humidity, and soil moisture readings. The motor control logic changes based on the number of days elapsed since the start of the program.